Typhus – how to identify and effectively treat a dangerous disease?

Typhus is an infectious disease that is characterized by a cyclical course, severe intoxication, the appearance of a rash, fever and damage to the central nervous and vascular systems.

Today, cases of infection are recorded in developing countries, but rarely in Russia and Ukraine. The causative agent of typhus is Provacek's rickettsia, an intracellular parasite of a non-motile gram-negative species. The microorganism received its name in honor of the Czech scientist who first discovered it. Although mass infections are mentioned back in the 16th century in Europe.

When dried, parasites can persist in the environment for a long time. Because of this fact, typhus pathogens can be found in bed linen, towels, and bathrobes in public places.

The main source of the disease is an infected person, who is more dangerous to others during the last few days of the incubation period, during fever and a week of normalized temperature. Typhus is spread by lice that suck the blood of a sick person, then become infectious after a few days. Upon contact with healthy individuals, the insect secretes infected feces, which penetrate the human epithelial cells and then into the blood through scratched areas.

Typhus

This is an acute infectious disease caused by rickettsia bacteria. The carriers of typhus are lice. In past centuries, these insects were very common among the poor population, for this reason the disease was very widespread. If a person fell ill in one house, his relatives and neighbors soon became infected. This type of typhus is characterized by the following symptoms: rash, fever, disruption of the cardiovascular and nervous systems. There are two forms: epidemic typhus and endemic.

The disease is extremely dangerous; there have been many deaths before, but modern medicine has learned to fight it. Typhus spreads quickly, and in Russia alone after the revolution, in 1917-1921, more than three million people died from it. But in 1942, an effective vaccine was developed. As a result, doctors prevented the epidemic.

Severe form

In severe forms of the disease, a condition occurs that is called “typhoid status” in medicine. It is characterized by the following manifestations:

• delusions and hallucinations;
• excitement;
• memory lapses;
• clouding of consciousness.

In addition to neuropsychiatric disorders, typhus in severe form is accompanied by severe weakness, insomnia (up to complete loss of sleep) and skin manifestations.

Symptoms of the disease last about 2 weeks. The rash is also observed in the third week. Then, with proper treatment, all manifestations of the disease gradually disappear.

How does infection occur?

The lice bite itself does not lead to infection. It occurs at the moment of scratching the skin, when the secretions left by lice are rubbed into the body. Typhoid is a disease with an incubation period of up to two weeks. Laboratory tests become positive only 7 days after infection.

The disease begins with chills, fever, severe headache and back pain. After a few days, a pink, spotted rash appears in the abdomen. The patient's consciousness begins to fog, speech becomes incoherent and hasty. Some people even sometimes fall into a coma. The temperature constantly remains at 40 degrees and drops sharply after 14 days. When typhoid epidemics occur, almost 50% of patients die.

Incubation period and initial symptoms

The incubation period of the disease ranges from 6 to 25 days. At this time, the person does not feel the symptoms of the pathology. Only at the end of the latent period may a slight discomfort be felt.

Then the person’s temperature rises sharply to +39 and even +40 degrees. The first signs of the disease appear:

• aches in the body and limbs;
• pain and feeling of heaviness in the head;
• feeling tired;
• insomnia;
• redness of the eyes due to hemorrhage in the conjunctiva.

Around the 5th day of illness, the temperature may drop slightly. However, the patient's condition does not improve. Signs of intoxication of the body are increasing. Subsequently, the high temperature returns again. The following symptoms are noted:

• redness and swelling of the face;
• nausea;
• coating on the tongue;
• cardiopalmus;
• drop in blood pressure;
• dizziness;
• disturbance of consciousness.

During a medical examination, already on the 5th day of the disease, an enlargement of the liver and spleen is noted. If you pinch the patient's skin, hemorrhage remains. The initial period of illness lasts about 4-5 days.

Brill's disease

This is a relapse, it is a little easier to tolerate, but has all the manifestations of typhus. The causative agent is Provacek's rickettsia, whose properties are completely similar to epidemic typhus bacteria. The disease is named after the person who first described it. It is not epidemic, but is transmitted through lice.

It may reappear after the first disease decades later. Main symptoms: severe headache, hyperesthesia of feelings, clouding of mind. There is facial hyperemia, but weaker than with typhus. In some patients, doctors additionally find Rosenberg enanthema. This is a very profuse rash, but sometimes the disease occurs without it.

Diagnostics

The diagnosis of typhus is based on the presence of high temperature, acute onset, specific rash and characteristic features: the formation of petechiae during the Sterling-Leede-Rumpel test and rubbing the skin with an elastic band (with a medium-hard pencil eraser, rub the skin of the subclavian region three to four times, after which 15 minutes stripes of tiny bright red petechiae are formed). From the 4-5th day, an agglutination reaction with Proteus X19 appears.

Differential diagnosis from typhoid fever with profuse rash, which can involve the limbs and even give primary and secondary petechiae, is quite difficult. In these cases, it is necessary to pay attention to the condition of the tongue (dry and thin - in typhoid fever, thickened, moist with a juicy coating - in typhoid fever), early enlargement of the spleen, intestinal phenomena and the absence of conjunctivitis in typhoid fever.

Sometimes the rash of typhus, when it is not abundant, is pink and covers only the skin of the false ribs, is similar to typhoid fever. In these cases, bacteriological and serological diagnosis are necessary for early recognition.

Typhus can sometimes be confused with measles when an erythematous-papular macular rash, conjunctivitis, runny nose and bronchitis are present. The formation of secondary and primary petechiae in the tests described above, the absence of typical measles enanthema, Filatov-Koplik spots, stages of the rash, typical rash damage to the center of the face and leukopenia - decide the issue in favor of typhus.

Meningococcal sepsis with secondary damage to the meninges can be confused with typhus. The rash with meningococcal sepsis is extremely similar to typhus. Typical symptoms of damage to the meninges and a spinal puncture resolve the issue. Possible confusion with purpura variolosa, for which, in addition to an extremely severe condition, a drop in temperature after the rash is typical.

Typhus falls into two forms: anergic and reactive. Between these two forms there are a number of transitional forms. The energetic form is characterized by a sharp depression of the central nervous system, early developing cardiovascular weakness, cyanotic rash, and symptoms of progressive collapse. The reactive form is characterized by a roseolous-papular rash, good blood supply to the skin, an enlarged spleen from the 8-9th day of illness, moderate dryness of the tongue and its moisturizing from the 9-10th day of illness, moderate confusion (nocturnal delirium) and a slight weakening of the heart. activities with a slight decrease in blood pressure.

Epidemiological typhus

An infectious disease caused by Provacek's rickettsia. This is a classic transmissible anthroponosis. Infection occurs mainly from a person who suffers from typhus. Epidemic typhus is a type of typhus.

To treat this disease, tetracycline antibiotics are used, which should be taken up to 5 times a day. If the form of the disease is severe, chloramphenicol succinate is prescribed, taken 3 times a day. The causative agent of epidemic typhus is bacteria that infect body lice. Through them, infection occurs. Head lice are found in a smaller area than body lice, which is why the epidemic factor is limited.

Cause of illness

The disease occurs due to rickettsiae entering the body. Humans are very susceptible to the microorganism that causes typhus. In microbiology, rickettsiae are considered to occupy an intermediate position between bacteria and viruses. The infectious agent can penetrate the walls of blood vessels and remain there for a long time. Sometimes a microorganism lives inside a person for years, and manifestations of the disease occur only when the immune system is weakened. Rickettsia are classified as bacteria, but their ability to invade cells is more characteristic of viruses.

The causative agent of typhus dies at temperatures above +55 degrees in about 10 minutes. A temperature of +100 degrees destroys rickettsia almost instantly. Also, this bacterium does not tolerate exposure to disinfectants. However, the microorganism tolerates cold and drying well.

Symptoms and course of the disease

As mentioned above, the causative agent of epidemic typhus is Provacek's rickettsia. The disease begins very acutely. Within a few days the temperature rises to a critical level. The patient suffers from severe headaches, insomnia and incessant vomiting. Some may experience mental and neurological disorders, when consciousness darkens and even euphoria appears.

The skin of a sick person is hyperemic, and heart function is disrupted from the first days. Typhus often causes hypotension, tachycardia, and irregular heart rhythms. Upon examination, an enlarged spleen and liver are revealed. Sometimes there are problems with urination, liquid comes out drop by drop, with severe pain.

On the fifth day of illness, a rash appears on the body, mainly on the sides and limbs. With a more severe course of the disease, rashes can be observed on the face and neck. Sometimes there are complications in the form of meningitis. If you begin to treat epidemic typhus immediately, without wasting precious time, then it will completely disappear within two weeks.

Symptoms

Identifying the symptoms of typhus at an early stage helps to completely get rid of the pathogen if appropriate treatment measures are taken. Like many diseases, this disease is best treated at an early stage, and in order to identify it, you need to know the main symptoms of the disease.

Typhus is characterized by three forms of the disease, which are called: initial, peak and complications. The incubation period lasts from 6 to 25 days and is characterized by a cyclical course of the disease.

Symptoms of the initial stage

The initial form is characterized by an increase in a person’s body temperature to 39 and, in rare cases, 40 degrees. At the same time, fatigue, headaches and muscle aches slowly begin to appear. A person with the first symptoms of the disease is characterized by a prodromal manifestation. The duration of sleep decreases, insomnia occurs, and unintentional heaviness appears in the head. Everything leads to general malaise of the body.

Symptoms of typhus in children

After 3-4 days, febrile symptoms appear throughout the body. But already on the fifth day the temperature drops to 37 degrees. At the same time, all other symptoms remain and even worsen. The fever becomes constant, intoxication increases and general exhaustion of the body increases. Along with headaches, dizziness and hyperesthesia (disorders of the sensory organs) occur. It is common for a person to experience vomiting, a coated tongue and dryness. A disturbance of consciousness occurs.

Important symptoms of the initial stage are:

• Redness of the facial skin;
• Reduced blood pressure;
• The occurrence of tachycardia;
• The appearance of hemorrhages on the body after pinching it.

A medical examination reveals hyperemia and swelling on the face. If you feel a person’s skin, it has a characteristic sign of dryness. The second day of localization of typhus is characterized by the appearance of hemorrhages in the folds of the conjunctiva and endothelial symptoms. From the third day, hemorrhage occurs in the transitional folds of the conjunctiva. From the fifth day, hepatosplenomegaly and increased vascular fragility appear. All these symptoms determine the initial form of the disease, which gradually develops into the peak stage.

Signs of heat form

Symptoms of the height form of typhus

Symptoms of the high stage are characterized by the appearance of a rash all over the body. Often, the first signs of a rash appear already on the 6th day, and closer to the tenth day they spread throughout the body. At the same time, headaches only intensify and recur more and more often. Fever becomes a common condition for a person with typhus.

The rash primarily appears on the extremities, and then along the torso. It looks like thick, bumpy pimples that cause itching all over the body even before they appear. The rash almost never appears on the face, feet or palms. In this case, the tongue takes on a brownish appearance, which indicates the progression of hepatomegaly.

Pain occurs in the lumbar area, which indicates the appearance of pathology in the renal vessels. A person experiences problems such as bloating, constipation and prolonged urination. Urination is characterized by pain, which is caused by atony of the bladder. In this case, it is typical to release urine one drop at a time.

Often the height of the disease causes swelling of the tongue, which leads to problems chewing food and speaking. Sometimes the form of fever is characterized by the appearance of such diseases:

• dysphagia;
• anisocoria;
• nystagmus;
• weakening of the pupils.

The most dangerous end of the high stage leads to the appearance of meningitis.

Meningitis

Signs of severe form

The severe form is caused by the appearance of typhoid status, characterized by:

• the occurrence of mental disorders;
• psychomotor agitation;
• talkativeness;
• violation of self-awareness;
• the appearance of memory gaps.

Severe symptoms last from 4 to 10 days.

On the part of the digestive system, enlargements of the liver and spleen are observed, which can be detected by ultrasound.

During sleep, hallucinations appear, leading to night awakenings. There is practically no sleep at this stage, which affects the nervous system. After the expiration of a two-week period, all of the above symptoms gradually disappear, except for the rash. The disease enters the convalescent stage.

The rash and weakness may continue for another week, after which they also gradually disappear.

Symptoms of Brill's disease

Symptoms of Brill's disease

Brill's disease is caused by almost identical symptoms to the main symptoms of typhus. This disease is a recurrent typhus syndrome and occurs due to the presence of the pathogen in the body for a long period. Manifestation occurs in the case of active reproduction of Provachek's rickettsia, which is caused by a decrease in immunity. The so-called passive pathogen of typhus, which can remain in the human body for a long time.

Symptoms of the disease almost always have the same severity, only they occur in a milder form. Body temperature does not rise above 38 degrees, and it is caused by frequent changes. The duration of febrile manifestations is halved, which means it lasts about a week.

The disease is characterized by an exceptionally mild form of the disease and there are no phases of peak and complications. Diagnosis is the same as for typhus disease. It was noticed that this disease manifested itself even after the 20-year period.

How to detect typhus

It is very difficult to make a correct diagnosis in the first days of the disease, since the symptoms are similar to those of other diseases. For correct diagnosis, test results are needed to help determine the disease. Typhus may initially resemble syphilis, influenza, measles, pneumonia and a number of other ailments. The person is checked for the presence of lice, contacts with typhus patients, etc. Differential methods are sometimes used, when the doctor separates symptoms from similar diseases.

After 5-6 days, the diagnosis can be made more confidently, based on the nature of the rashes and the timing of their appearance, facial hyperemia, changes in the nervous system and a number of other indicators. Doctors also carefully study blood tests.

Laboratory tests are then carried out to identify typhoid bacteria. Serological tests detect the presence of parasites in the blood and confirm an accurate diagnosis. All this time, complex therapy is applied to the person, which helps relieve symptoms. Targeted drugs against typhus are prescribed only after doctors are sure that the patient has this particular disease.

Causes

The direct causative agent of both types of typhus is Provacek's rickettsia, which is a cross between viruses and bacteria. These pathogens are quite resistant to maintaining viability at high temperatures, but heating to 50 degrees causes their death.

The main reasons why the disease can be localized in humans is direct contact with virus carriers. These carriers are lice, which differ in their characteristic properties. The body louse retains its vital activity in clothes and underwear. This louse becomes infected by sucking the blood of an animal infected with typhus.

Once the louse has landed on the patient’s body, it also becomes infectious within 5–6 days. The disease is transmitted through contact with an infected parasite, which is especially dangerous on the 2nd–3rd day of the incubation period.

Vectors of typhus

For your information! The transmission of typhus from a sick person to a healthy person is almost impossible.

A much lower probability of infection with typhus is present in head lice, but still it is not completely excluded. In addition, scientists have proven that the head louse also has the ability to infect, but has much less potential to damage the human body. It has only been proven that the pubic louse is not a carrier of the disease.

Lice infection does not occur immediately; initially, rickettsia enters the parasite's intestines with the blood, after which the rickettsia accumulates and multiplies. As a result, the intestines become clogged with viruses, and the louse becomes a full-fledged carrier of typhus.

The causative agent of typhus

The duration of viability of an infected louse is short-lived and takes about 3 weeks, after which blockage of the intestines leads to its self-destruction. When a louse lands on the body, it is not yet dangerous, and after suction, defecation occurs. When sucking blood, this parasite actively secretes mucus, which actually causes itching. This mucus, entering the body, is the source of infection of the body with the disease typhus.

The possibility of infection of the body with the help of lice feces, which enter through the respiratory tract, cannot be ruled out. In this case, the ingested feces settle on the mucous membrane of the respiratory tract, where they are localized in the body.

A high probability of infection with typhus is present during violations of hygienic living conditions (wars, famine and other social upheavals).

Often, the provocation of the disease occurs in the event of activation of rickettsia, which persisted after incomplete cure of typhus.

The repeated manifestation of the disease is called “Brill’s disease”, based on the same symptoms, only the cause of its occurrence is a decrease in immunity, but this is described in more detail below.

Epidemic typhus, treatment

Tetracycline antibiotics are considered the main drugs. If a person has intolerance to them, then the drug “Levomycetin” is used. The drug "Tetracycline" is prescribed more often. Taken orally 4 times a day. If the disease is severe, then for the first two days intravenous or intramuscular injections of chloramphenicol sodium succinate are given 3 times a day.

When the body temperature becomes normal, the medicine is taken in the usual dosage. Sometimes complications may arise due to the use of antibiotics. It occurs as a layering of a second disease, such as pneumonia. In this case, additional medications are prescribed.

Causal therapy usually gives a very rapid effect, and as a result, vaccine therapy and long-term oxygen therapy are not required. Vitamins are used as pathogenetic drugs. Mostly ascorbic acid and vasoconstrictor drugs are prescribed.

Typhoid is a disease that can cause serious complications. They are especially common in older people who have reduced immunity. They are additionally prescribed anticoagulants. They prevent the development of thrombohemorrhagic syndrome. The most effective of these drugs is Heparin. Elderly people need to take it as soon as an accurate diagnosis is established. The duration of taking such medications is from three to five days.

Diagnosis of the disease

Algorithm for diagnosing typhus

Diagnosis of typhus includes three types of studies:

1. General.
2. Additional.
3. Specific.

Diagnosis through a general examination includes:

• Blood analysis. When a person becomes ill, an increase in ESR is observed, the quantitative composition of platelets decreases, and giant granulocytes appear.
• Analysis of cerebrospinal fluid, on the basis of which lymphocytic cytosis is determined.
• Biochemical research. Based on this, a decrease in the quantitative composition of the protein is determined, the ratio of albumins and globulins is disrupted.

Diagnostic measures through an additional type include conducting studies of individual organs through:

• ECG;
• Ultrasound;
• EEG;
• X-rays of light.

Based on these data, the doctor draws appropriate conclusions, but if there is reason to doubt the research results, then a specific diagnosis is prescribed. Most specialists start with this type.

Specific diagnostics consists of serological methods, which are characterized by:

1. Carrying out an indirect hemagglutination reaction (IRHA), through which the picture of the composition of antibodies in the body is clarified. If typhus is present, the test will be positive.
2. An enzyme immunoassay can detect the presence of class G and M antigens, so if IgM antigens are detected, this indicates the initial stage of the disease. IgG - speaks of Brill's disease.
3. The component ligament reaction is the most accurate method for detecting the presence of antibodies, but the only drawback is that its accuracy lies in the duration of the disease. The stage of height and complications is detected 100%.

Prevention of epidemic typhus

The causes of diseases lie in lice, so you need to start fighting them. It is advisable to prevent their appearance at all. Early diagnosis is also important. It is necessary to isolate the patient in time and, if possible, hospitalize. In the hospital, he must undergo thorough sanitary treatment. Clothes are disinfected.

For prophylaxis, a formaldehyde-inactivated typhoid vaccine containing dead Provacek's rickettsia is used. Now, thanks to timely and high-quality treatment and prevention of typhus, vaccination is no longer required on a large scale. The incidence has decreased significantly.

Complications

During the height of the disease, a serious complication is possible - infectious-toxic shock. It occurs as a result of poisoning of the body with rickettsia poisons. In this case, there is acute failure of the heart, blood vessels and adrenal glands. Before this complication, the patient’s temperature often drops. The periods from 4 to 5 and from 10 to 12 days from the onset of the disease are considered especially dangerous. It is at this time that the risk of developing this complication is increased.

Typhus can cause complications on blood vessels and the brain. Thrombophlebitis or meningitis occurs. Rickettsia is often associated with another bacterial infection. The patient develops signs of pneumonia, otitis, furunculosis, as well as inflammatory diseases of the genitourinary organs. These pathologies are often accompanied by suppuration, which can lead to blood poisoning.

The patient has to remain in bed. This can cause bedsores, and in severe cases, gangrene can develop due to vascular damage.

Endemic typhus

An acute infectious disease caused by Muzer's rickettsia. The second type of bulk. Typhoid carriers are small rodents (rats, guinea pigs, etc.). That is why it has several other names:

• rat;
• classical;
• lousy;
• prison or ship fever.

Very common among small wild rodents. They are the natural reservoir for the virus. You can become infected not only through contact with them, but also by eating food that contains urine or feces of rat or mouse fleas. And also through scratching the skin, when their feces get into them. The disease can also be transmitted through tick bites on sick rodents.

Other types of typhus

In addition to typhus, there is also typhoid and relapsing fever. However, these are completely different diseases that are not caused by rickettsia. The word “typhoid” in medicine refers to infectious pathologies accompanied by fever and clouding of consciousness.

Typhoid fever is caused by salmonella and is not transmitted by lice. The pathology occurs with signs of damage to the gastrointestinal tract.

Relapsing fever is caused by spirochetes. The bacteria are spread by mites and lice. This disease is also characterized by fever and rashes. The pathology must be differentiated from the rash form. Relapsing fever always has a paroxysmal course.

Typhoid fever

An acute anthroponotic intestinal infection caused by Salmonella bacteria, which produce endotoxin that is pathogenic only for humans. Does not create disputes. The disease is characterized by: fever with general intoxication of the body, skin rash, damage to the lymphatic system and small intestine.

After infection has occurred, the maximum number of viral bacteria is formed in the third week. Transient carriers release the virus into the environment within 14 days. In acute cases of the disease, this process can continue for three months. In the chronic form, typhoid bacillus is secreted for several years.

Typhoid fever is transmitted by the fecal-oral route. Mainly through water, but there is also a possibility of infection at home and through food intake. People are very susceptible to this disease, but if they get sick, they develop strong immunity. Therefore, a typhoid fever vaccination is given in advance.

The disease mainly appears in areas with contaminated water and poor sewage systems. Adults and teenagers most often become infected from water, and small children - during milk outbreaks. The disease usually occurs in summer and autumn.

Pathogenesis

Rickettsia affects the adrenal glands and blood vessels. The body develops a lack of the hormone adrenaline, which leads to a drop in blood pressure. Destructive changes occur in the vascular walls, which causes a rash.

Damage to the heart muscle is also noted. This is due to intoxication of the body. The nutrition of the myocardium is disrupted, which leads to degenerative changes in the heart.

Typhoid nodules (granulomas) form in almost all organs. They especially affect the brain, which leads to severe headaches and increased intracranial pressure. After recovery, these nodules disappear.

Symptoms and course of typhoid fever

Divided into several periods. Initially, in the first week, intoxication manifests itself progressively. Typhoid fever symptoms during this period are as follows: the skin turns pale, weakness appears, the headache intensifies, a significant or complete decrease in appetite occurs, and bradycardia begins. A pale coating is visible on the tongue, constipation or diarrhea is tormented.

The height of the disease occurs on the tenth day. The temperature is high and does not decrease, intoxication is pronounced. There is lethargy, irritability, and a pale pink rash appears in the form of roseolae protruding above the skin. It appears on the stomach, chest, side of the body, and on the bends of the limbs. The heart beats dullly, hypotension and bradycardia begin. The coating on the tongue turns brown, and teeth marks are visible along the edges. The stomach becomes bloated and constipation occurs. The spleen and liver enlarge, consciousness is impaired, the patient begins to delirium, and hallucinations appear. Even toxic shock may occur if the condition is very severe.

After the disease begins to recede, the temperature drops sharply. The recovering person has a good appetite, sleep is restored, weakness disappears, and overall health improves greatly.

The period of convalescence is dangerous with relapses, which can occur in 10% of patients. Precursors: the spleen and liver do not normalize, appetite weakens, weakness returns, and general malaise increases again. Clinical manifestations are the same as the course of the underlying disease, but shorter in duration.

Typhoid fever can be mild, moderate or severe. There are also two atypical ones - erased and abortive. They occur more often now, due to the use of antibiotics in treatment and the use of immunoprophylaxis. The fever lasts for a week, but can last three days. Often the onset of the disease is very acute, and serological reactions can be negative throughout the course of the disease.

Clinical picture

The incubation period for typhus ranges from 8-10 to 13-14 days. A prodromal period lasting 3-4 days is often observed. The prodromal period, often characterized by patients as a “premonition” of the disease, actually comes down to a number of symptoms: poor sleep, dull muscle pain, shortness of breath, catarrh of the pharynx and upper respiratory tract, low-grade fever, headache. The onset of a developed reaction (disease) is characterized by chills, a rapid, often step-like rise in temperature, reaching a maximum during the first four days of the disease. Usually on the 4-5th day the temperature gives a morning drop, forming a kind of indentation on the temperature curve, then in the evening it rises again and remains at a high level until the 8th day, when it again gives a morning drop, but more significant than on the 8th day. 5th day. By the evening of the 8th day it rises again and lasts until the 12th day, when it decreases and then, in several large steps, reaches the norm by the 14-16th day of illness. Thus, temperature remissions divide typhus into 4 periods of 4 days duration, and incisions in the temperature curve are usually accompanied by diuresis. This division is not artificial, since each period has its own biological and clinical characteristics.

⇒ The first period (days 1-4) is a period of warming up the body and increased reproduction of the pathogen in the internal organs.

⇒ In the second period (5-8th day) there is an increased expulsion of the pathogen into the bloodstream, which is clinically manifested by a rash.

⇒ By the beginning of the third period (8-12th day), immune bodies appear and in this period of “biological recovery,” which is the most difficult, intense interaction occurs between the micro- and macroorganism.

⇒ Its natural continuation is the fourth period of “clinical recovery” - the period of crisis (13-16th day).

Sometimes (especially in children) a shortened temperature reaction is observed, lasting 9-10 days, or, conversely, extended to 20-22 days. Typhoids of the shortened type produce real crises, while typhus of the extended type often lead to lysis. In some cases, on the 5-6th day after the temperature drops, slight increases are observed that last for several days (temperature tails).

In severe forms of the disease, the usual drop in temperature for typhus on the 5th and 8th day may be absent.

Rash

With typhus on the 1st day, enanthema is quite often observed in the form of several round hemorrhages on the soft palate at the base of the tongue. Exanthema normally appears on the 5th day, but can also appear on the 1st-7th day. It is located first on the lateral surfaces of the chest - on the skin covering the false ribs, on the skin of the elbow, mastoid processes (variably). The rash gradually, over the next three days, occupies a larger or smaller surface of the skin, spreading even to the palms, soles and scalp, sometimes giving repeated rashes not only in the later days of the illness, but even after the crisis.

Roseolous-papular rash occurs in those forms of typhus that give a good prognosis; sometimes miliary vesicles appear on the roseopapules. They can be distinguished from prickly heat by their small size and pink corolla of roseola. Some of the roseolas develop into secondary petechiae - hemorrhages that appear in the center of the roseolas. Along with these secondary petechiae, primary petechiae are also observed, especially in those places where the skin is stretched (elbow folds). Roseola is usually round in shape, the diameter of its individual elements varies from 1 to 2 cm.

Secondary petechiae sometimes look like short stripes, while primary petechiae resemble a pin prick. The color of roseola is pale pink, but under the influence of impregnation with blood pigment it can turn into a dirty reddish-brown. In severe cases, the rash may be entirely petechial. Along with this typical rash, successive erythemas of a spotty nature, with exudative phenomena, can be observed.

The rash usually lasts 5-6 days, but petechiae remain until the 12-15th day of illness. Roseola disappears, leaving behind weak pigmentation even when there were no secondary petechiae. The more energetic the skin reaction, i.e. the pinker the rash, the more pronounced the inflammatory reaction in roseola and the better blood circulation in the skin, the better the prognosis; the more petechiae, the worse the prognosis; the prognosis is poor when large spots form on the skin along with small petechiae, spreading like drops of ink on a piece of paper.

Petechiae, if they are not visible, can be easily caused artificially - by tightening the shoulder above the elbow for a few minutes; in this case, hemorrhages appear in the skin below the site of constriction (Leede-Rumpel, Sterling symptom). The same, but even smaller petechiae can be caused by rubbing the skin of the subclavian area with an elastic band. In some forms, the rash appears to be faintly translucent. Finally, there may be cases that occur without the appearance of a rash.

Typhus without rash occurs at epidemic levels of 6-8%. Its course is somewhat milder: this form is predominantly found in children and adolescents. The tongue becomes, starting from the third day of illness, dry, flesh-red in color: sometimes there is a pale orange spot on the back surface of the tip; the papillae of the tongue are raised, forming longitudinal pectinate elevations. The tongue quickly becomes covered with a brown-brown coating. The nasal mucosa swells and becomes covered with drying mucus, making it difficult to breathe through the nose. The patient breathes with an open mouth, which further increases the dryness of the mouth. The complexion in the first 4 days is either pale or, conversely, red; the latter depends on neuroparalytic hyperemia associated with damage to the superior and middle nodes of the cervical sympathetic nerve. Eyelids squinted or compressed; the connective membrane is hyperemic, the pupils are narrow, the corneas are shiny. The entire face appears swollen due to increased skin turgor (the conjunctiva of the eyeballs and eyelids turns red).

Patients seek peace; they are irritated by sounds, smells, light, and feeding. The voice becomes hoarse. Breathing in the lungs is somewhat weakened. Heart sounds are muffled; the pause between systole and diastole is shortened; The pulse either corresponds to the temperature or lags somewhat behind it.

The skin is dry, but sometimes it gets moisturized with sweat in the morning. By the end of the first five-day period and, in any case, with typhus of moderate severity from the second five-day period, the patient’s condition changes sharply due to the ensuing weakening of the circulatory system and a disorder of the nervous system. Heart sounds become muffled, murmurs appear, expansion of the boundaries of the heart is observed both due to the ventricles and the right atrium, blood pressure decreases, and with further deterioration of the condition, cyanosis and shortness of breath occur. In severe cases, embryocardia appears. By the end of the second five-day period, the phenomena of meningo-encephalitis, sometimes mildly expressed, occur. The improvement is reflected primarily in the fact that the skin becomes softer and moist, takes on a normal color, the drop in blood pressure is not so pronounced and sometimes a slight perspiration appears in the early morning hours. The pulse quickens. The amount of urine increases. The puffiness of the face disappears. By the end of the third five-day period, with favorable current forms, cardiac activity begins to gradually improve, the pulse slows down somewhat and the temperature begins to decrease from the 12th day. After the crisis, the patient seems stunned for about 7 days, but consciousness is usually quickly restored along with the desire, which does not correspond to the slowly growing reparative processes, to be discharged as quickly as possible and get to work.

Changes in the cardiovascular system

The first clinical alarm signal from the heart is the appearance of an additional third sound at the apex. The appearance of this tone indicates overstrain of the heart muscle, which may cause cardiac arrest.

In addition to the additional tone at the apex, attacks of suffocation, cyanosis, increased heart rate and often profuse sweating are observed at this time. In this case, increasing cardiovascular asthenia is characterized by a decrease in the conductivity of the heart muscle; the atria contract frequently (tachysystole), but due to damage to the conduction pathways, the rhythm of ventricular contractions lags behind the contractions of the atria, and arrhythmia develops. Individual contractions of the ventricles are transmitted to the chest wall in the form of worm-like contractions and are clearly visible in persons with thin outer integuments. The subsequent expansion of the atrium is detected by an increase in relative dullness in the area of ​​the second intercostal space and the right edge of the manubrium of the sternum. Shortly before death, a gallop rhythm appears, indicating a significant weakening and depletion of the muscular strength of the heart. Sometimes a blowing diastolic murmur appears at the base of the heart, apparently dependent on atrial flutter.

The course of typhus is characterized by hypotension. Already by the 4th day of illness, blood pressure in adults drops: systolic - up to 100 mm Hg. Art., and diastolic - up to 70-85, and this decrease progresses until the 8-12th day of illness.

If there is no significant increase in heart rate, pulse pressure may seem normal to the touch, but the pressure gauge shows an ominous drop. If by the 12th day the blood pressure begins to rise, then this is a favorable symptom. The appearance of circulatory shortness of breath with a decrease in blood pressure is a poor prognostic sign.

Blood picture in typhus

The blood picture in this disease shows significant changes: the number of red blood cells decreases, their diameter increases due to water retention. During the entire febrile period, moderate leukocytosis with a shift to the left and lymphopenia is observed. The number of eosinophils sometimes drops to zero, Turk cells reach 8-10%. Basophilic inclusions of Dele and Provacek are often found in the protoplasm of leukocytes. Changes in the blood return to normal fairly soon after the crisis.

The Weil-Felix agglutination reaction with the blood serum of patients with typhus has not only great diagnostic, but also epidemiological significance. The reaction from the 4th-5th day of illness is positive in 45%, from the 6th - in 70%, from the 7th - in 86%, and from the 9th-10th day it is positive in 95-98% of patients. In the remaining 2-5%, it can appear only during the period of convalescence. After recovery, this reaction in most cases disappears after 3 months (rarely lasts up to a year).

Typhus at the beginning of its development revives and resumes the so-called anamnestic agglutination reaction in relation to the typhoid group, if the patient had previously suffered typhoid fever or paratyphoid fever; the Vidal reaction associated with vaccination is also revived if the patient has previously been vaccinated with typhoid vaccine.

The Weil-Felix reaction acquires great epidemiological significance when it appears in healthy people or in cases representing a mild, indeterminate febrile illness. The increase in both the number of such diseases and the increase in the reaction of healthy people is a categorical indication of the need to carry out the most energetic measures to improve the health of the area (fighting lice, improving living conditions, isolating feverish people, etc.). During hikes and long stays in places infected with typhus, repeated tests for the Weil-Felix reaction should be carried out periodically.

When assessing the Weil-Felix reaction, you need to keep in mind that it is often positive in Bang disease and Malta fever. Globulins are easily precipitated when the blood serum of patients with typhus is diluted with distilled water. Veltman's reaction - mixing 1:10 distilled water with typhus serum taken at the end of the 2nd week, causes the formation of a precipitate due to the precipitation of globulins. The latter can replace the Weyl-Felix reaction.

Changes in the nervous system

Already in the first days of the disease, irritation of the central nervous system is detected in the form of increased talkativeness and general agitation. From the 5-6th day, the state of excitement gives way to depression, and later the patient falls into a delirious state. Even with great willpower and mild forms of typhus, it is difficult to stay within the limits of normal thinking. Delirium can take on a calm or violent character. Delusional ideas have the most diverse nature: professional, migration, split personality, musical, erotic; delusions are often induced by illusory ideas, actions and speeches of others, and often contain colorful, vivid pictures, usually of a frightening nature. Very often the subject of delirium is attempts against property and person. Delusional ideas can persist for a long time after recovery and acquire the character of asthenic confusion. Patients need the most careful supervision and all sharp objects should be removed from them.

There is no doubt that in addition to changes in the cerebral cortex, changes in the semicircular canals and labyrinth play a role in the nature of delirium. Exacerbation of visual, auditory, gustatory and olfactory perceptions, as well as skin and tactile sensitivity, are observed no less often.

The phenomena of meningoencephalitis are also typical of typhus; clinically, they manifest themselves in severely ill patients between the 8th and 10th day of illness with an increase in muscle twitching in the muscles of the face, hand and forearm; breathing diverges from the pulse, becoming more frequent and interrupted by deep sighs, the pupils narrow, lacrimation appears, the injection of the conjunctiva intensifies: after these initial phenomena, as the process progresses, breathing acquires a Biotian character; the pulse becomes irregular, blood pressure drops uncontrollably, facial muscles, especially facial muscles, twitch more and more, and these grimaces primarily cover the area of ​​the mouth and eye slits. When brought out of this state, the patient sluggishly answers questions and then falls into oblivion again.

If meningoencephalitis progresses, the corneas begin to fade, the swallowing reflex is disrupted and sucking movements of the lips appear, protruding them, with the appearance of saliva bubbles. In some cases, patients lie with their mouths slightly open, obediently endure the infusion of liquid into the mouth and feeding, but do not swallow the injected nutrients and often retain them in the oral cavity and cheek pouches. Tears flow from the eyes, and a stream of saliva flows from the half-open mouth. Rigidity of the limbs and Kernig's sign (usually one-sided) appear. The pulse is rapid and small, and traces of protein appear in the urine. Blood pressure drops uncontrollably. The limbs, nose and ears are either pale or cyanotic. In 40%, a profuse, spotted cyanotic rash appears. This condition was formerly called "coma vigilans". Hiccups occur frequently. Patients can remain in this state for 3-4 days before death. In the cerebrospinal fluid there are signs of an inflammatory process: increased pressure, pleocytosis, and in 30% a positive Nonne-Appelt reaction.

Death after a crisis is even more tragic. Two days after the temperature drops, the patient develops excruciating pain in the mesogastric region, accompanied by vomiting, hiccups and belching. The face becomes cyanotic in color. Cardiac activity increases to the degree of embryocardia, heart sounds are muffled, the pulse is small, soft, urination increases, breathing is rapid and shallow, often of the Biot type; the temperature either drops below normal or rises sharply, and with symptoms of increasing cardiac weakness, while maintaining consciousness, patients die in prolonged agony, sometimes lasting more than a day. In both the first and second cases, patients literally swim in their own urine, and hospital staff are exhausted changing the sheets under them.

With paresis of the splanchnic nerve, accompanied by a flow of blood into the abdominal cavity, collapse phenomena develop: the patient complains of dizziness, nausea (brain anemia), tension and dull pain in the abdomen; the face turns pale, the pulse becomes frequent, weak and small, visible veins become empty, dull tones and noises are heard in the heart. Vomiting is common.

In typhus, both motor and sensory nerve fibers are affected. Neuralgia during typhus is observed mainly in the area of ​​the trigeminal and occipital nerves. These neuralgia, having begun during the prodrome, can continue not only during illness, but also for a long time after recovery. Most often, damage to the ulnar nerve is observed, leading the area innervated by it to paresthesia, paresis and paralysis. The long thoracic nerve is often affected, as well as other nerves of the upper shoulder girdle, sometimes even the entire brachial bundle. Paralysis of the nerves of the upper girdle is observed mainly in persons engaged in manual labor. In some cases of typhus, changes are also observed in the nerves of the extremities (peroneal nerve). Of the sensory nerves, the optic and auditory nerves are relatively often affected. If the development of neuritis of the motor nerves occurs after a crisis, it is often accompanied by feverish temperature fluctuations.

Changes in the gastrointestinal tract

Typhus is usually accompanied by constipation. During the crisis and often after it, some patients experience vomiting, mainly in women. Vomiting occurs without preliminary nausea; patients feel great after vomiting and do not lose their appetite. With regard to the prognosis, this symptom has no significance, and after a few days it disappears without a trace.

The liver in patients with typhus from the 2nd week is enlarged by 100% and is sensitive to pressure. Apparently, as autopsies and histological studies have shown, this increase depends on active hyperemia of the liver, followed by stagnation as cardiac activity weakens. The liver reaches normal size only 2-3 weeks after the crisis.

Bile retention is not observed, therefore, with typhus, retention jaundice is very rare.

Changes in the respiratory system

The voice of patients with typhus is weak and hoarse. Laryngoscopy reveals swelling and hyperemia of the laryngeal mucosa. Perichondritis is rare. Breathing is usually rapid, but does not vary with the temperature. Changes in breathing with significant damage to the heart and central nervous system can be very diverse, and breathing often takes on a Kussmail-Biot or Chain-Stokes character.

Active hyperemia of the lungs, the presence of which is shown by autopsy data, develops by the end of the first five days. Due to the expansion and overflow of blood in the vessels surrounding the alveoli, the air capacity of the alveoli decreases, which affects breathing, which becomes frequent and shallow. In patients with typhus, in addition, symptoms of dry bronchitis are observed. Irritation of the vagus nerve leads to hypersecretion of the mucous membrane of the bronchial tree, as a result of which bronchopneumonia develops, mainly in the lower lobes of the lungs. Physical phenomena in these bronchopneumonias are often insignificant and are reflected upon percussion by dullness with a tympanic tinge, and upon auscultation by hard breathing, dry rales and deep crepitus. Bronchopneumonic foci can merge, and then, with deterioration of cardiac activity, shortness of breath, cyanosis and a drop in blood pressure develop. These pneumonias resolve simultaneously with the crisis of the underlying disease, and often in the next 2-3 days after it all physical phenomena completely disappear.

In addition to these pneumonias, characterized by a slight cough, insignificant secretion of glassy sputum, poor in formed elements and almost devoid of microbial flora, occasional pneumonia may develop due to parainfection with influenza and pneumococcus. Pulmonary edema, which ends the picture of the disease in the dying, occurs as a result of extravasation of plasma through the walls of the pulmonary capillaries both into the cavity of the alveoli and into the interstitial tissue of the lung.

Heart attacks, abscesses and gangrene of the lungs are a fairly common occurrence with typhus: they usually develop in the late days of the illness between the 14th and 18th days. They are caused by parainfection. The changes are located in the lower lobes.

Pleurisy, as a primary disease, rarely occurs in typhus. If they appear during pneumonia, abscesses, heart attacks and gangrene, they often take on an exudative and even purulent character. Typically, catarrhal laryngitis accompanying typhus rarely gives rise to serious complications.

Changes in the kidneys

Clinically, a relatively slight increase in specific gravity is observed in the urine, despite the high temperature and low fluid supply. The specific gravity remains around 1.018-1.020, increasing only on some days (sweating) to 1.030.

Quite often traces of protein, an insignificant amount of hyaline, less often granular casts and single red blood cells are found in the urine; from the 5th-6th day of illness, a diazoreaction and a reaction to urobilinogen usually appear.

Prevention of typhoid fever

Prevention is considered the main way to combat this disease. It involves a set of measures, many of which are controlled by the health care system. The causes of diseases can be different and lie in dirty water, contaminated products, and unsanitary conditions. Therefore, strict controls and epidemiological checks are carried out.

Doctors are observing groups of people who may be carriers of typhoid fever. All persons on whom the possible spread of the disease depends are controlled. These are workers of medical institutions, public utilities, water stations and catering.

Disease prevention also involves long-term follow-up of a recovered person. Patients are discharged only after tests have shown negative results five times in a row. After this, the recovered person regularly takes them to the clinic at his place of residence for three months. After this period, he is tested twice a year for typhoid fever.

People who have been ill, even after recovery, must constantly monitor their temperature. And at the slightest increase, even if it’s just a common cold, go to the clinic to check if the disease has returned again. Because such cases sometimes happen.

If a healthy person has been in contact with a sick person, then a 21-day medical observation is prescribed. At this time, blood, feces and urine are examined, typhoid bacteriophage is given, and vaccination is used. The pathogenic bacillus is very resistant to the external environment, so if hygiene rules are not followed, there is a high probability of infection.

The period of the height of the disease

A rash appears on day 5-6. Skin manifestations of typhus are associated with vascular damage by rickettsia. There are two types of rashes associated with this disease - roseola and petechiae. Different types of rashes can occur on one area of ​​the skin. Roseolas are small spots (up to 1 cm) of pink color. The appearance of such rashes can be seen in the photo below.

Petechiae are pinpoint subcutaneous hemorrhages. They are formed due to increased permeability of the walls of blood vessels. The rash covers the torso and limbs. Palms, soles of feet and face remain clean. There is no itching. In the photo you can see what petechiae-shaped rashes look like.

The coating on the tongue turns brown at the height of the disease. This indicates progressive damage to the spleen and liver. Body temperature is constantly elevated. Other symptoms of typhus are also noted:

• excruciating headache;
• difficulty urinating;
• confusion;
• difficulty swallowing food;
• involuntary vibrations of the eyeballs;
• lower back pain associated with renal vascular damage;
• constipation;
• bloating;
• rhinitis;
• signs of inflammation of the bronchi and trachea;
• slurred speech due to swelling of the tongue.

When peripheral nerves are damaged, radiculitis-type pain may occur. An enlarged liver is sometimes accompanied by yellowing of the skin. However, liver pigments remain within normal limits. Changes in skin color are associated with impaired carotene metabolism.

The disease lasts about 14 days. With proper treatment, the temperature gradually decreases, the rash disappears and the person recovers.

Relapsing fever - what is it?

This species combines epidemic and endemic. During illness, fever alternates with normal body temperature. Relapsing fever can be found everywhere in the world, in almost every country. It is only absent in Australia, since this continent is located far from the rest. The highest incidence is observed in African countries and India. Large outbreaks of the disease have been reported in Russia and the Balkan Peninsula. The causative agent of typhus is Borrel spirochetes. Tick-borne relapsing fever is a vector-borne zoonotic disease. Its causative agents are many bacteria called Borrelia.

Relapsing fever is transmitted by ticks and rodents, which are the natural reservoir of the disease. Ticks infected with typhus retain the virus throughout their lives. Viral bacteria can also be transmitted transovarially, penetrating the eggs of arthropods.

Human infection occurs through tick bites. A papule forms at this site, and after some time the disease itself develops. The population of endemic areas has low susceptibility to this disease, but among visitors it is very high. Therefore, tourists are always advised to take appropriate preventive vaccinations and be extremely careful. This is especially true for those people who want to visit African countries.

In epidemic relapsing fever, infection occurs when the bite is scratched and insect feces are rubbed into the skin. If the bacteria remain outside and do not penetrate the blood, they die quickly (within half an hour). Therefore, if you are bitten by a tick, it is strictly forbidden to scratch the area affected by the insect. You have to endure it, even though it’s unpleasant. Epidemic relapsing fever is a disease that affects only humans; animals are not afraid of it.

And finally, here are some tips to help avoid possible infection. It is imperative to maintain personal hygiene and undergo regular medical examinations. It is not recommended to visit places where unsanitary conditions flourish and insects dangerous to humans can be found. Before traveling abroad, it is better to find out if there are any epidemics in the country you want to visit. This is especially true in Asia and Africa. Even if no danger is observed, extreme caution should be exercised.

Treatment methods

If a diagnosis such as typhus is confirmed, the patient is admitted to a hospital. Until a persistent decrease in temperature, a person is prescribed bed rest for about 8-10 days. Medical staff need to prevent bedsores in patients, as well as constantly monitor blood pressure.

No special diet required. Food should be gentle, but at the same time sufficiently high in calories and rich in vitamins.

Drug treatment of typhus should be aimed at solving the following problems:

• combating the pathogen;
• removal of intoxication and elimination of neurological and cardiovascular disorders;
• elimination of symptoms of pathology.

Tetracycline antibiotics are most effective against rickettsia. The following drugs are prescribed:

• "Doxycycline";
• "Tetracycline";
• "Metacycline";
• "Morphocycline".

Usually a person feels better within 2-3 days of antibacterial treatment. However, the course of antibiotics must be continued until body temperature normalizes. Sometimes doctors prescribe taking antibacterial medications until complete recovery.

In addition to tetracyclines, antibiotics of other groups are also prescribed: Levomycetin, Erythromycin, Rifampicin. They help prevent the addition of a secondary bacterial infection.

To relieve intoxication of the body, droppers with saline solutions are placed. To eliminate symptoms of the heart and adrenal glands, Caffeine, Adrenaline, Norepinephrine, Cordiamin, and Sulphocamphocaine are prescribed. Antihistamines are also used: Diazolin, Suprastin, Tavegil.

If you have a high fever, your doctor may recommend antipyretics. However, you should not get too carried away with them, as these drugs can provoke cardiovascular complications.

Anticoagulants play an important role in therapy: Heparin, Phenindione, Pelentan. They prevent the formation of thrombotic complications. Thanks to the use of these drugs, mortality from typhus has decreased significantly.

If the patient experiences clouding of consciousness, insomnia, delirium and hallucinations, then antipsychotics and tranquilizers are indicated: Seduxen, Haloperidol, Phenobarbital.

In severe forms of the disease, Prednisolone is prescribed. To strengthen blood vessels during typhoid, therapy is carried out with the drug “Ascorutin” with vitamins C and P.

The patient is discharged from the hospital no earlier than 12-14 days of illness. After this, the sick leave is extended for at least 14-15 days. Next, the patient is under clinical observation for 3-6 months. He is recommended to undergo examinations by a cardiologist and a neurologist.

Pathogenesis [edit | edit code ]

The gates of infection are minor skin lesions (usually scratching), after 5-15 minutes the rickettsiae penetrate into the blood, a small part of them dies, the rest enters the lymph flow and is sent to the regional lymph nodes, where they multiply (primary reproduction), this period corresponds to the incubation period. After which there is a massive release of rickettsia into the bloodstream (primary rickettsia), some of the rickettsia die, and endotoxin is released, and the acute period of the disease begins. Rickettsia penetrates the vascular endothelium and multiplies. This leads to swelling and desquamation of endothelial cells. The cells that enter the bloodstream are destroyed, and the released rickettsiae infect new endothelial cells. The most rapid process of reproduction of rickettsia occurs in the last days of the incubation period and in the first days of fever.

Epidemiology [edit | edit code]

The identification of typhus as an independent nosological form was first made by Russian doctors Y. Shchirovsky (1811), Y. Govorov (1812) and I. Frank (1885). A detailed distinction between typhoid and typhus (based on clinical symptoms) was made in England by Murchison (1862) and in Russia by S. P. Botkin (1867). The role of lice in the transmission of typhus was first established by N. F. Gamaleya in 1909. The infectiousness of the blood of patients with typhus was proven by the experience of self-infection by O. O. Mochutkovsky (the blood of a patient with typhus was taken on the 10th day of illness, introduced into the skin incision of the forearm, O. O. Mochutkovsky’s disease occurred on the 18th day after self-infection and was severe). The incidence of typhus increased sharply during wars and national disasters, the number of cases amounted to millions.

The outstanding microbiologist Alexey Vasilyevich Pshenichnov, MD, PhD, devoted his life to the study of epidemiology and the development of methods for treating rickettsial diseases. Department of Microbiology, Perm State University (PSU), head of the viral-rickettsial department of the Research Institute of Vaccines and Serums, Perm. A. V. Pshenichnov studied in detail the life cycle of different strains of rickettsia, created a medium for cultivating rickettsia in laboratory conditions outside the “host” organism. A great contribution to the study of the epidemiology of typhus was made by his sons Pshenichnov Vadim Alekseevich (military doctor, general, for a long time - deputy director for science of the Research Institute of Microbiology in Zagorsk) and Robert Alekseevich Pshenichnov, who headed the rickettsial laboratory, and then, together with his father, created and headed Department of Ecology and Genetics of Microorganisms (today Institute of Ecology and Genetics of Microorganisms, Ural Branch of the Russian Academy of Sciences).

Currently, the high incidence of typhus remains only in some developing countries. However, the long-term persistence of rickettsia in those who previously had typhus and the periodic occurrence of relapses in the form of Brill-Zinsser disease does not exclude the possibility of epidemic outbreaks of typhus. This is possible when social conditions deteriorate (increased population migration, head lice, deteriorating nutrition, etc.).

The source of infection is a sick person, starting from the last 2-3 days of the incubation period until the 7-8th day from the moment the body temperature normalizes. After this, although rickettsiae can persist in the body for a long time, the convalescent no longer poses a danger to others. Typhus is transmitted through lice, mainly through body lice, less often through head lice. After feeding on the blood of a patient, the louse becomes infectious after 5-6 days and until the end of life (that is, 30-40 days). Human infection occurs by rubbing lice feces into skin lesions (in scratches). There are known cases of infection from blood transfusions taken from donors in the last days of the incubation period. Rickettsia circulating in North America ( R. canada

), transmitted by ticks.

Prevention

The basis of prevention is the systematic extermination of rodents (deratization), especially in port cities, as well as the prevention of their importation from incoming ships. If there are a significant number of rats, it is necessary to ensure that they do not enter the premises (especially food warehouses and stores) to prevent contamination of food with the excrement of infected animals. Timely identification of the outbreak of rat rickettsiosis followed by mandatory deratization and disinsection is important. In the absence of carriers, a patient with endemic typhus does not pose a danger to others. Vaccination against endemic typhus is not used.

Transmission routes

This disease is transmitted transmissibly, that is, through the blood. The source of infection is a sick person, and the carriers of typhus are body lice. That is why infection of the population with pediculosis can provoke the spread of the pathology. In more rare cases, infection occurs through blood transfusion from a sick person.

The louse becomes infected approximately 5-6 days after being on the body of a sick person and remains infectious for about a month. Then the insect dies. The disease is not transmitted by lice bites. The parasites' saliva does not contain rickettsia. The bacteria accumulate in the intestines of these insects and are then excreted in the feces. Typically, pediculosis in humans is always accompanied by severe itching. The patient becomes infected when he introduces lice excrement into scratches and lesions on the skin.

Epidemiologists suggest another route of transmission. A person can inhale particles of parasite feces. In this case, the causative agent of typhus enters the body through the mucous membrane of the respiratory tract. Then the rickettsiae begin pathogenic activity in the body.

Can head lice be carriers? Doctors believe that these insects can also transmit the disease, but much less frequently than body parasites. Pubic lice are not able to transmit rickettsia.

The spread of lice can provoke infection with typhus. In the past, outbreaks of this disease often occurred in adverse conditions, during times of war or famine, when hygiene and sanitation levels dropped sharply.

The disease leaves behind immunity, but not absolute. Repeated cases of infection in rare cases were still observed. In medical practice, even triple infections with rickettsia have been recorded.

Brief historical background [edit | edit code]

Typhus was originally a disease of the Old World. The name “typhos” was first used by the ancient Greek physician Hippocrates.

In the history of wars, typhus often turned out to be a decisive factor: the number of victims of this disease often exceeded losses in battles, as, for example, in the Thirty Years' War, during Napoleon's invasion of Russia, in the Crimean War, in the First World War. In post-revolutionary Russia, typhus killed about 3 million people between 1917 and 1921.

In 1942, an effective vaccine for the prevention of typhus was developed by Alexey Vasilyevich Pshenichnov. The People's Commissariat of Health of the RSFSR ordered the directors of the Molotov, Irkutsk, and Moscow institutes to create departments for vaccine production. The widespread use of the vaccine made it possible to prevent a typhus epidemic in the active army and in the rear during the Great Patriotic War.

The fact that epidemics of typhus more often occur in the cold season and during periods of hostilities, when the “infestation of lice” increases and large groups of people live crowded together in unsuitable living conditions, suggested that lice are the carriers of the disease. In 1909, Charles Nicole proved that the causative agent of typhus from person to person is the body louse Pediculus humanus corporis

, for which he was awarded the Nobel Prize in Physiology or Medicine in 1928. A head louse can also transmit typhus, a pubic louse is extremely rare. The role of animals as a reservoir of infection has not been established. Between epidemics, the infection is maintained in a dormant state among people who are chronic carriers of pathogenic rickettsiae. Episodic cases of an infection called Brill's disease (a recurrent form of typhus) sometimes occur in the eastern United States.

In children

In children, typhus develops with a certain set of clinical signs. Most often, the disease does not appear immediately. This makes diagnosis much more difficult.

However, the child tends to exhibit prodromal signs. Prodromal signs appear as follows:

• loss of child activity;
• weakness;
• apathy;
• increased arousal;
• fever.

Fever is manifested by a significant increase in body temperature. The child also has rashes. Nervous disorders are quite pronounced. The child develops a delusional state.

There is a certain tendency for the disease to develop in children. Typhus may have a hidden, unexpressed course. This is especially true for kids. Therefore, the disease is not detected immediately.

To treat a child, a whole range of measures is carried out. This takes into account the child’s condition, the presence of complications and the course of the disease. The treatment process is aimed at the following therapeutic measures:

• maintaining body systems;
• sedatives;
• means that support the activity of the heart.

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How to prevent infection and spread of infection

To prevent the disease, it is necessary to combat head lice. Doctors notify the sanitary-epidemiological station about each case of typhus. At the source of infection, bedding, linen and clothing are treated and disinfested. If, after carrying out measures to prevent typhus, parasites still remain on the patient’s personal belongings, then the treatment is repeated until they are completely eliminated.

It is necessary to establish medical surveillance of all people who have been in contact with the patient. The maximum duration of the incubation period of the disease is up to 25 days. During this period, it is necessary to regularly measure the temperature and inform the doctor about any deviations in health.

Currently, all patients with prolonged fever (more than 5 days) are prescribed serological blood tests for rickettsia. This is one of the measures to prevent typhus. Prolonged persistence of high temperature is one of the signs of this disease. It must be remembered that mild forms of the disease can occur with minor rashes, and it is not always possible to identify pathology by skin manifestations. Doctors have proven that in rare cases, asymptomatic carriage of rickettsia occurs. Therefore, testing is one of the ways to detect infection early and prevent the spread of the disease.

Epidemiology

Source of infection and reservoir

Endemic typhus is a zoonotic infection common among rodents - gray and black rats (Rattus norvegicus and Rattus rattus), European and American subspecies of house mice, which are the reservoir of the pathogen in nature.

Other rodents (voles, gerbils, marmots, etc.) may also be susceptible to this infection, and domestic cats can also be infected from rodents directly through their ectoparasites. In rodents, infection can last a long time and be asymptomatic. Rodents become infected by contact, by eating food contaminated with the excrement of sick animals, through infected ectoparasites - rat fleas (Xenopsylla cheopis), mouse fleas, and sometimes cat fleas (Ctenocephalides felis), which do not attack humans under normal conditions, as well as certain types of gamas. ticks, in which the infection can be transmitted transovarially.

Mechanism and factors of transmission

Humans become infected when rickettsiae from dried feces of ectoparasites come into contact with the mucous membranes of the eyes, mouth, upper respiratory tract, and damaged skin. Occasionally, people become infected through the bites of gamasid ticks.

Susceptible contingent and immunity

In humans, endemic typhus occurs, as a rule, in the form of a sporadic incidence throughout the year with a maximum in the summer-autumn period, which is due to the high activity of rodents and ectoparasites during this season of the year. The disease is registered mainly among people in contact with rodents - workers of food enterprises, sellers of grocery stores, warehouses, residents of houses inhabited by rodents, etc. During the hunting season, cases of the disease are recorded among hunters. The disease is usually not transmitted from person to person, but in conditions of significant infestation of the population, transmission of the causative agent of endemic typhus through human body louse is sometimes possible, resulting in epidemic outbreaks similar to epidemic typhus, as happened in Mexico, China and Africa . After an illness, stable antitoxic and antibacterial immunity is formed, repeated diseases and relapses are not recorded. During the infectious process, it is possible to form unstable, unstressed cross-immunity between Muser's and Provasek's rickettsia, which does not happen after vaccination.

Treatment

Epidemic typhus, in fact, like endemic typhus, has a general treatment picture. First of all, therapeutic measures include keeping the patient in bed and complete rest. It is imperative to provide him with a diet that does not contain all foods that negatively affect the body (fried, smoked). Treatment of typhus also includes the use of the following techniques:

• Etiotropic;
• Antibacterial;
• Pathogenic;
• Symptomatic.

The etiotropic method of treatment involves therapy through the use of tetracyclic drugs: metacycline, tetracycline, morphocycline and doxycycline. Depending on whether epidemic or endemic typhus predominates in a person, appropriate drugs from this series are prescribed. But the drug doxycycline, which has maximum effectiveness, is considered the most popular among doctors.

Forecast

With tick-borne typhus, the prognosis depends on the condition of the patient. The more severe the condition, the worse the prognosis. The state of immunity plays a significant role.

Immunity helps to cope with possible complications. Even if complications do not always appear. The prognosis also depends on the prescribed treatment.

Only proper adequate treatment can cope with the disease. Including improving the forecast. The prognosis is best with the right medication approach.

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Diagnosis [edit | edit code]

The diagnosis of sporadic cases in the initial period of the disease (before the appearance of a typical exanthema) is very difficult. Serological reactions also become positive only from the 4th to 7th day from the onset of the disease. During epidemic outbreaks, the diagnosis is facilitated by epidemiological data (information about morbidity, the presence of lice, contact with patients with typhus, etc.). When exanthema appears (that is, from the 4th to 6th day of illness), a clinical diagnosis is already possible. The timing and nature of the rash, facial hyperemia, Rosenberg enanthema, Chiari-Avtsyn spots, changes in the nervous system - all this makes it possible to differentiate primarily from typhoid fever (gradual onset, lethargy of patients, changes in the digestive organs, later appearance of exanthema in the form of a roseolo-papular monomorphic rash, absence of petechiae, etc.).

It is necessary to differentiate from other infectious diseases that occur with exanthema, in particular, with other rickettsioses (endemic typhus, tick-borne rickettsiosis of North Asia, etc.). The blood picture has some differential diagnostic value. Typhus is characterized by moderate neutrophilic leukocytosis with a band shift, eosinopenia and lymphopenia, and a moderate increase in ESR.

To confirm the diagnosis, various serological tests are used. The Weil-Felix reaction, an agglutination reaction with Proteus OXig, has retained some significance, especially with an increase in antibody titer during the course of the disease. Most often, RSCs with rickettsial antigen (prepared from Provacek's rickettsiae) are used; the diagnostic titer is considered to be 1:160 or higher, as well as an increase in antibody titer. Other serological reactions are also used (microagglutination reaction, hemagglutination reaction, etc.).

A memorandum from the WHO meeting on rickettsial diseases (1993) recommended indirect immunofluorescence as the recommended diagnostic procedure. During the acute phase of the disease (and the convalescence period), antibodies are associated with IgM, which is used to distinguish them from antibodies resulting from a previous illness. Antibodies begin to be detected in the blood serum from the 4-7th day from the onset of the disease, the maximum titer is reached 4-6 weeks from the onset of the disease, then the titers slowly decrease. After suffering from typhus, Provacek's rickettsia remain in the body of the convalescent for many years, this causes long-term persistence of antibodies (associated with IgG also for many years, although in low titers). Recently, trial therapy with tetracycline antibiotics has been used for diagnostic purposes. If, when tetracycline is prescribed (in usual therapeutic doses), body temperature does not normalize after 24-48 hours, then this allows us to exclude typhus (if the fever is not associated with any complication).

Rickettsia Provacek

The causative agent of the disease is Provacek's rickettsia, which are microorganisms that parasitize the endothelial cells of blood capillaries. Under natural conditions, Provacek's rickettsia multiply in the endothelial cells of the blood capillaries of a sick person and in the epithelial cells of the intestinal wall of lice infected with them. Rickettsia can be cultivated in the lung tissue of white mice and on the chorion-allantoic membrane of a chicken egg embryo, which is used to obtain vaccines against typhus (Durand and Cox vaccines). Rickettsia quickly die in a humid environment, but persist for a long time in lice feces and in a dried state. They die at a temperature of 100 degrees, under the influence of conventional disinfectants.

How is typhoid transmitted: sources of infection

Typhus can only be transmitted by body lice and head lice. The source of infection can be animals and an infected person. After sucking blood containing rickettsia bacteria, the insects end up on the skin and hair areas of the body. Carrying out their vital functions, they lay eggs and excrement.

It is important to establish a diagnosis of typhus or suspect its presence in the first 4 days of the disease, since the louse becomes infectious to other persons from the 5th day after the infectious bloodsucking

After the penetration of rickettsia, the bacterium begins to rapidly multiply in the insect’s body. The incubation period is 4-5 days.

The insect bites a person, injecting toxins into the epidermis. Each time they suck blood, the lice have a bowel movement. The skin becomes irritated by the injected toxins, causing itching and scratching. When louse feces enter the wound surface of the epidermis, the circulatory system becomes infected with rickettsia bacteria.

Routes of infection:

1. In some situations, infection can occur through the air. Shaking bedding or underwear with dried mite feces can lead to infection. Once in the pulmonary tract, the bacterium wakes up and begins to actively multiply, affecting the circulatory and nervous systems.
2. Infections are known from donor blood transfusions taken during the last stages of the incubation period of an infected person.
3. Lice are very sensitive to changes in body temperature and quickly move from a sick host with a fever or a deceased person, crawling onto other people.

Dried feces retain a long lifespan; in case of massive and prolonged gatherings of people and prolonged non-handling of things, a chain mechanism of disease transmission occurs in 90% of cases.

Prevention and prevention

The incidence of typhus in the population has decreased significantly thanks to Order No. 342 developed by the Ministry of Health on the prevention of lice. This document regulates the correctness of preventive measures.

A number of preventive procedures include:

1. Carrying out scheduled inspections. They should be carried out by a medical worker at a preschool or school institution, dormitories, orphanages, or boarding schools.
2. Ensuring sanitary conditions.
3. Availability of personnel to carry out routine inspections.
4. Organization of special events in areas of infection.
5. Information and explanatory work.

With the development of pediculosis, Order 342 states that carriers and infected people are people who have been found to have live, dry or dead lice, as well as nits.

If infection is established, each case must be registered and information transferred to the epidemiological service. A person should not visit public places for 2 weeks. During this period he must undergo a course of therapy. When an infection is detected in a team, regular inspections are carried out throughout the month.

Complications[edit | edit code]

Provacek's Rickettsia parasitizes the vascular endothelium, and in connection with this, various complications can occur - thrombophlebitis, endarteritis, pulmonary embolism, cerebral hemorrhage, myocarditis. Predominant localization in the central nervous system leads to complications such as psychosis and polyradiculoneuritis. The addition of a secondary bacterial infection can cause pneumonia, otitis, mumps, glomerulonephritis, etc. With antibiotic therapy, when all manifestations of the disease disappear very quickly, and even in mild forms of the disease, pulmonary embolism is almost the only cause of death in patients. As a rule, this happened already during the recovery period, at normal body temperature. Often the complication was provoked by an increase in a person’s physical activity.

History of world epidemics, part 2

In the first part of the History of World Epidemics, we talked about plague and smallpox. Today we will remember the horrors that cholera “gave us” - its outbreaks were observed 7 times in less than 200 years, and typhus - only during the First World War in Russia and Poland 3.5 million people died from it.

Illustration from 1866. Source

Cholera

Cholera is caused by motile bacteria - Vibrio cholerae, Vibrio cholerae. Vibrios reproduce in plankton in salt and fresh water. The mechanism of cholera infection is fecal-oral. The pathogen is excreted from the body through feces, urine or vomit, and enters a new body through the mouth - with dirty water or through unwashed hands. Epidemics are caused by mixing wastewater with drinking water and lack of disinfection.

The bacteria produce an exotoxin, which in the human body causes ions and water to leak out of the intestines, leading to diarrhea and dehydration. Some types of bacteria cause cholera, others cause cholera-like dysentery.

The disease leads to hypovolemic shock, a condition caused by a rapid decrease in blood volume due to loss of water, and death.

Cholera has been known to mankind since the time of the “father of medicine” Hippocrates, who died between 377 and 356 BC. He described the disease long before the first pandemic, which began in 1816. All pandemics spread from the Ganges Valley. The spread was facilitated by heat, water pollution and mass gatherings of people near rivers.

The causative agent of cholera was isolated by Robert Koch in 1883. The founder of microbiology, during cholera outbreaks in Egypt and India, grew microbes on gelatin-coated glass plates from the feces of patients and the intestinal contents of the corpses of the dead, as well as from water. He was able to isolate microbes that looked like curved sticks, similar to a comma. Vibrios were called "Koch's comma".

Scientists have identified seven cholera pandemics:

1. First pandemic, 1816–1824
2. Second pandemic, 1829–1851
3. Third pandemic, 1852–1860
4. Fourth pandemic, 1863–1875
5. Fifth pandemic, 1881–1896
6. Sixth pandemic, 1899–1923
7. Seventh pandemic, 1961–1975

A possible cause of the first cholera epidemic was abnormal weather, which caused a mutation of Vibrio cholerae. In April 1815, the Tambora volcano erupted in what is now Indonesia, a magnitude 7 disaster that claimed the lives of ten thousand island residents. Up to 50,000 people then died from the consequences, including starvation.

One of the consequences of the eruption was the “year without summer.” In March 1816 it was winter in Europe, there was a lot of rain and hail in April and May, and there were frosts in America in June and July. Germany was tormented by storms, and snow fell every month in Switzerland. A mutation of Vibrio cholerae, perhaps coupled with famine due to cold weather, contributed to the spread of cholera in 1817 throughout Asia. From the Ganges the disease reached Astrakhan. More than 30,000 people died in Bangkok.

The pandemic was stopped by the same factor that started it: the abnormal cold of 1823-1824. In total, the first pandemic lasted eight years, from 1816 to 1824.

The calm was short-lived. Just five years later, in 1829, a second pandemic broke out on the banks of the Ganges. It lasted for 20 years - until 1851. Colonial trade, improved transport infrastructure, and the movement of armies helped the disease spread throughout the world. Cholera reached Europe, the USA and Japan. And, of course, she came to Russia. The peak in our country occurred in 1830-1831. Cholera riots swept across Russia. Peasants, workers and soldiers refused to tolerate quarantine and high food prices and therefore killed officers, merchants and doctors.

In Russia, during the second cholera epidemic, 466,457 people fell ill, of whom 197,069 died. The spread was facilitated by the return of the Russian army from Asia after the wars with the Persians and Turks.

Emperor Nicholas I pacifies the cholera riot in St. Petersburg in 1831 with his presence.
Lithograph from the French periodical Album Cosmopolite. Dated 1839. Source The third pandemic dates back to the period from 1852 to 1860. This time, more than a million people died in Russia alone.

In 1854, 616 people died from cholera in London. There were many problems with sewerage and water supply in this city, and the epidemic led to the fact that they began to think about them. Until the end of the 16th century, Londoners took water from wells and the Thames, and also for money from special tanks. Then, over the course of two hundred years, pumps were installed along the Thames, which began pumping water to several areas of the city. But in 1815, sewers were allowed to be drained into the same Thames. People washed, drank, and cooked in water, which was then filled with their own waste—for seven whole years. The sewers, of which there were about 200,000 in London at the time, were not cleaned, leading to the “Great Stench” of 1858.

London physician John Snow discovered in 1854 that the disease was transmitted through contaminated water. Society did not pay much attention to this news. Snow had to prove her point to the authorities. First, he persuaded the handle of the water stand on Broad Street, where the outbreak was centered, to be removed. He then compiled a map of cholera cases, which showed the relationship between the locations of the disease and its sources. The largest number of deaths was recorded in the vicinity of this particular water intake. There was one exception: no one died in the monastery. The answer was simple - the monks drank exclusively beer of their own production. Five years later, a new sewer system scheme was adopted.

An advertisement in London, distributed in 1854, ordered the consumption of only boiled water.

The seventh and last cholera pandemic began in 1961. It was caused by the more persistent Vibrio cholerae in the environment, called El Tor - after the name of the quarantine station where the mutated Vibrio was discovered in 1905.

By 1970, El Tor cholera had spread to 39 countries. By 1975 it was observed in 30 countries. At the moment, the danger of cholera being imported from some countries has not gone away.

The highest rate of spread of infection is shown by the fact that in 1977, a cholera outbreak in the Middle East spread to eleven neighboring countries, including Syria, Jordan, Lebanon and Iran, in just a month.

Early 20th century magazine cover

In 2019, cholera is not as bad as it was one hundred or two hundred years ago. Many more people have access to clean water, and sewage rarely goes into the same bodies of water that people drink from. Sewage treatment plants and water supply are on a completely different level, with several degrees of purification.

Although cholera outbreaks still occur in some countries. One of the most recent cases of a cholera epidemic began (and continues) in Haiti in 2010. In total, more than 800,000 people were infected. During peak periods, up to 200 people fell ill per day. The country is home to 9.8 million people, meaning cholera has affected almost 10% of the population. It is believed that the epidemic was started by Nepalese peacekeepers who brought cholera into one of the country's main rivers.

On November 8, 2019, the country announced mass vaccination. They plan to vaccinate 800,000 people within weeks.

Cholera in Haiti. Photo: RIA Novosti

In October 2019, it was reported that Aden, Yemen's second largest city, had two hundred cases of cholera, with nine deaths. The disease spread through drinking water. The problem is exacerbated by famine and war. According to the latest data, cholera is suspected in 4,116 people throughout Yemen.

Typhoid

Under the name “typhoid”, which translated from ancient Greek means “cloudness of consciousness”, several infectious diseases are hidden at once. They have one common denominator - they are accompanied by mental disorders against the background of fever and intoxication. Typhoid fever was identified as a separate disease in 1829, and relapsing fever in 1843. Before this, all such diseases had one name.

Typhus

A group of infectious diseases collectively called typhus is caused by the rickettsia bacteria, intracellular parasites named after Howard Taylor Ricketts (pictured), who described the causative agent of Rocky Mountain spotted fever in 1909.

In the United States, this fever is still common, with up to 650 cases of the disease reported annually. The spread is evidenced by the fact that between 1981 and 1996, the fever was found in every US state except Hawaii, Vermont, Maine and Alaska. Even today, when medicine is at a much higher level, the mortality rate is 5-8%. Before the invention of antibiotics, the death rate reached 30%.

In 1908, Nikolai Fedorovich Gamaleya proved that the bacteria that causes typhus are transmitted by lice. Most often - clothes, which is confirmed by outbreaks in the cold season, periods of “lice”. Gamaleya substantiated the importance of disinfestation in order to combat typhus.

Bacteria enter the body through combs or other damage to the skin. After a louse has bitten a person, the disease may not occur. But as soon as a person begins to itch, he rubs the lice’s intestinal secretions, which contain rickettsiae. 10-14 days after the incubation period, chills, fever, and headache begin. After a few days, a pink rash appears. Patients experience disorientation, speech impairment, and temperature up to 40 °C. Mortality during an epidemic can be up to 50%.

In 1942, Alexey Vasilyevich Pshenichnov, a Soviet scientist in the field of microbiology and epidemiology, made a huge contribution to the methodology for the prevention and treatment of typhus and developed a vaccine against it. The difficulty in creating a vaccine was that rickettsia cannot be cultivated using conventional methods - the bacteria need living animal or human cells. A Soviet scientist has developed an original method of infecting blood-sucking insects. Thanks to the rapid launch of the production of this vaccine in several institutes during the Great Patriotic War, the USSR managed to avoid an epidemic.

The time of the first typhus epidemic was determined in 2006, when the remains of people found in a mass grave under the Acropolis of Athens were examined. The Plague of Thucydides killed more than a third of the population of Athens in one year in 430 BC. Modern molecular genetic methods have made it possible to detect the DNA of the causative agent of typhus.

Typhus sometimes struck armies more effectively than a living enemy. The second major epidemic of this disease dates back to 1505-1530. The Italian doctor Fracastor observed her with the French troops besieging Naples. At that time, high mortality and morbidity rates of up to 50% were noted.

In the Patriotic War of 1812, Napoleon lost a third of his troops from typhus. Kutuzov's army lost up to 50% of its soldiers from this disease. The next epidemic in Russia was in 1917-1921, this time about three million people died.

Currently, antibiotics of the tetracycline group and chloramphenicol are used to treat typhus. Two vaccines are used to prevent the disease: the Vi-polysaccharide vaccine and the Ty21a vaccine, developed in the 1970s.

Typhoid fever

Typhoid fever is characterized by fever, intoxication, skin rashes and damage to the lymphatic system of the lower small intestine. It is caused by the bacterium Salmonella typhi. Bacteria are transmitted in the same way as in the case of typhus - through the nutritional, or fecal-oral, route. In 2000, 21.6 million people worldwide suffered from typhoid fever. The mortality rate was 1%. One of the effective ways to prevent typhoid fever is washing your hands and dishes. As well as careful attention to drinking water.

Patients experience a rash - roseola, brachycardia and hypotension, constipation, enlargement of the liver and spleen and, which is typical for all types of typhus, lethargy, delirium and hallucinations. Patients are hospitalized and given chloramphenicol and biseptol. In the most severe cases, ampicillin and gentamicin are used. In this case, it is necessary to drink plenty of fluids, possibly adding glucose-salt solutions. All patients take leukocyte production stimulants and angioprotectors.

Relapsing fever

After being bitten by a tick or louse, a carrier of the bacterium, a person begins the first attack, which is characterized by chills, followed by fever and headache with nausea. The patient's temperature rises, the skin dries out, and the pulse quickens. The liver and spleen enlarge, and jaundice may develop. Signs of heart damage, bronchitis and pneumonia are also noted.

The attack lasts from two to six days, and repeats after 4-8 days. If the disease after a louse bite is characterized by one or two attacks, then tick-borne relapsing fever causes four or more attacks, although they are milder in clinical manifestations. Complications after the disease - myocarditis, eye damage, spleen abscesses, heart attacks, pneumonia, temporary paralysis.

For treatment, antibiotics are used - penicillin, chloramphenicol, chlortetracycline, as well as arsenic drugs - novarsenol.

Death from relapsing fever is rare, except in central Africa. Like other types of typhus, the disease depends on socio-economic factors - in particular, nutrition. Epidemics among populations without access to qualified medical care can result in a mortality rate of up to 80%.

During the First World War in Sudan, 100,000 people died from relapsing fever, that’s 10% of the country’s population.

Edvard Munch. "At the Deathbed (Fever)." 1893

Humanity has managed to control plague and smallpox in vitro thanks to the high level of modern medicine, but even these diseases sometimes break through to people. And the threat of cholera and typhus exists even in developed countries, let alone developing ones, where another epidemic may break out at any moment.

On November 4, 2019, it was reported that a typhoid epidemic was threatening Dagestan. In Makhachkala, about 500 people were hospitalized with acute intestinal infection after water poisoning. Two people were taken to intensive care. To prevent the epidemic, the Russian Ministry of Health planned to transfer the drugs Algavac M, Vianvac, Shigelvac and Intesti-bacteriophage.

The cause of infection in Makhachkala was tap water. The director of the local water utility has been arrested, and twenty-three other people are under investigation. Now residents of Rostov fear the same thing.

Tick ​​subspecies - differential diagnosis

Before the onset of the second stage of the disease, differential diagnosis is carried out with typhoid fever, syphilis, measles and other diseases that are characterized by a rash. Regardless of how severe the symptoms are, the diagnosis must be carried out in full.

When typhus occurs, the main symptoms remain, such as high body temperature and throbbing headache. The body is also covered with a petechial rash, which is more pronounced on the lateral surface of the body and the surfaces of the limbs on the inside. The tongue is always dry; over time, a brown coating forms on the mucous membrane.

Exodus

The outcome of this disease will depend on many factors. Deaths occur with tick-borne typhus in seven percent of cases. All other cases end in recovery.

After an illness, immunity is formed. Recovery is possible with timely diagnosis. Since after diagnosis, treatment begins immediately. Otherwise, a disorder develops in the central nervous system.

The outcome is favorable if the patient follows comprehensive treatment. In this case, the entire complex of drugs is important. Otherwise, the prognosis is not encouraging. Up to the development of severe damage to the central nervous system.

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Lice incubation period: how to avoid disease

After infection with rickettsia, the insect continues to live and function normally. In the insect's body, bacteria begin to multiply at high speed. Rickettsia viruses are tenacious and are able to resume their activity even in a dried state. When they enter the human body, they begin to multiply quickly.

Already on the 5th day, feces release a huge number of rickettsiae, which are deposited on:

• Fabric surfaces;
• Epidermis;
• And hairy parts of the body.

The reaction of the patient’s immune system occurs only after 2 weeks, and symptoms begin caused by intoxication of the body, damage to the vascular membranes and the nervous system. Rash is a skin manifestation of the disease. It takes about 2 weeks from the moment of infection to the first symptoms, so turning to specialists occurs already at the height of the disease.

Typhoid pathogens

There are several types of typhus, each of which has its own pathogens. So the rash form is caused by the bacteria Rickettsia . They are very afraid of heat treatment and disinfectants. When exposed to boiling water, they die within a few seconds.

The abdominal form is caused by Salmonella bacteria , which produce endotoxin, which is harmful exclusively to the human body. This pathogen, unlike many others, cannot form spores and capsules. However, it is very resistant to low temperatures, but cannot withstand high temperatures; when exposed to boiling water, it dies immediately.

He is also afraid of disinfectants, dying from them in a few minutes. Dairy products are a favorable environment for these bacteria; they can stay there for several months. In addition, they live in soil and aquatic environments for about the same time, but in running water they can only live for a few days.

The recurrent form is caused by microorganisms belonging to the spirochetes of the genus Borrelia . The most common pathogen is Obermeyer's borella. They develop in the body of lice or ticks, through which infection occurs. These bacteria are also killed by boiling and disinfection. The epidemic form is caused by Provacek's rickettsia , which infects body lice. It is because of them that you can become infected with typhus.