What is relapsing fever. Relapsing fever - what insects should be afraid of? Relapsing fever methods of laboratory diagnostics

Relapsing fever(Latin typhus recurrens) is a collective name that combines epidemic (the carrier of the pathogen is a louse) and endemic (the carrier of the pathogen is a tick) spirochetosis, occurring with alternating bouts of fever and periods of normal body temperature.

The causative agents of relapsing fever are spirochetes of the genus Borrelia, in particular, one of the most common pathogens of epidemic typhus is Obermeier's Borrellia Obermeieri, discovered in 1868 by Otto Obermeier.

Tick-borne relapsing fever is a zoonotic vector-borne disease. The causative agents are many types of Borrelia: B. duttonii, B. persica, B. hispanica, B. latyschewii, B. caucasica, common in certain geographical areas. These borrelia are similar to the causative agent of epidemic relapsing fever in morphology, resistance to environmental factors, and biological properties.

A person becomes infected by tick bites. At the site of inoculation of the pathogen, a papule is formed (primary affect). The pathogenesis and clinical manifestations of tick-borne relapsing fever are similar to epidemic. Diseases often occur in the warm season with the activation of the vital activity of ticks.

The population of areas endemic for tick-borne relapsing fever acquires a certain degree of immunity to circulating pathogens - they have antibodies to borrelia common in this region in their blood serum. It is mainly visitors who get sick.

The carriers of epidemic V. typhus are the lice Pediculus humanus capitis (head), P. humanus humanus (clothes) and Phtirius pubis (pubic). The louse, having sucked the patient's blood, becomes capable of infecting a person throughout its life, since borrelia are non-pathogenic for lice, and microorganisms multiply well in the insect's hemolymph. There is no transovarial transmission of Borrelia in lice. A person becomes infected by rubbing lice hemolymph containing Borrelia (when combing a bite, crushing an insect) (contaminative infection). In the environment, Borrelia quickly die. Under the action of a temperature of 45-48 ° C, death occurs after 30 minutes. Epidemic relapsing fever only affects humans.

Pathogenesis (what happens?) during relapsing fever:

Once in the internal environment of the body, Borrelia invade the cells of the lymphoid-macrophage system, where they multiply, and then enter the blood in larger quantities. Under the influence of the bactericidal properties of blood, they are partially destroyed and endotoxin is released, damaging the circulatory and central nervous system. Toxicosis is accompanied by fever, and foci of necrosis appear in the spleen and liver. Due to the aggregates from borrelia formed under the influence of antibodies, which linger in the capillaries of internal organs, local blood supply is disrupted, which leads to the development of hemorrhagic infarcts.

The first febrile period of the disease ends with the formation of antibodies against the first generation Borrelia. Under the influence of these antibodies, microbial aggregates arise with a load of platelets and most of the Borrelia die. Clinically, this is expressed by the onset of remission. But some of the pathogens change their antigenic properties and become resistant to the formed antibodies, they remain in the body. This new generation of borrelias multiplies and, flooding the bloodstream, gives a new attack of fever. The resulting antibodies against the second generation of the pathogen lyse a significant part of them, but not completely. Resistant pathogens that have changed antigenic specificity, multiplying, again give a relapse of the disease. This is repeated several times. Recovery occurs only when a spectrum of antibodies appears in the blood, lysing all antigenic variants of Borrelia.

The transferred disease does not leave strong immunity. The formed antibodies remain for a short time.

Symptoms of relapsing fever:

The first attack begins suddenly: a short chill is replaced by fever and headache; there are pains in the joints and muscles (mainly calf), nausea and vomiting. The temperature rises quickly, the pulse is frequent, the skin is dry. The nervous system is involved in the pathological process, often delirium occurs (see DELIRIOUS). At the height of the attack, various forms of rash appear on the skin, the spleen and liver increase, and jaundice sometimes develops. During a fever, there may be signs of heart damage, as well as bronchitis or pneumonia. The attack lasts from two to six days, after which the temperature drops to normal or subfebrile and the patient's health improves rapidly. However, after 4-8 days, the next attack develops with the same symptoms. Cases without recurrences are rare.

For louse relapsing fever, one or two repeated attacks are characteristic, which end in complete recovery and temporary immunity. Tick-borne relapsing fever is characterized by four or more attacks of fever, they are shorter and milder in clinical manifestations, although the second attack may be more severe than the first.

Complications. Meningitis, iritis, iridocyclitis, uveitis, rupture of the spleen, synovitis. Previously observed icteric typhoid is a layering of salmonella infection.

Diagnosis of relapsing fever:

Recognition is based on epidemiological data, a characteristic clinical picture of the disease (acute onset, a critical drop in temperature with profuse sweating at the end of an attack, an early and significant enlargement of the spleen (splenomegaly), alternating febrile seizures and apyrexia). The data of the study of peripheral blood are of diagnostic value (moderate leukocytosis, especially during an attack, aneosinophilia, thrombocytopenia, increasing anemia, ESR increased).

Laboratory diagnostics
During an attack, at the height of the fever, the pathogen can be relatively easily detected in the patient's blood. To do this, preparations of a thick drop or blood smear are prepared, stained according to Romanovsky - Giemsa or magenta and microscoped. It is possible to microscope blood drops in a dark field, observing the mobility of Borrelia. The method of serological diagnostics consists in the formulation of lysis reactions, RSK.

Differentiation of epidemic from endemic relapsing fever is carried out in a biological experiment: a guinea pig is injected with the patient's blood. Borrelia of epidemic relapsing fever, unlike endemic ones, do not cause disease in the animal. With tick-borne typhus, the mumps falls ill for 5-7 days, and borrelia are found in its blood.

Treatment for relapsing fever:

Antibiotics (penicillin, chloramphenicol, chlortetracycline) and arsenic preparations (novarselon) are used to treat epidemic relapsing fever. In the treatment of tick-borne typhus, tetracycline antibiotics, levomycetin, and ampicillin are used.

Prevention of relapsing fever:

Prevention of epidemic typhus is reduced to the fight against lice, avoiding contact with lice patients. At present, epidemic relapsing fever does not occur in our country and in many others. Prevention of tick-borne relapsing fever is to protect people from tick attacks, the destruction of rodents and insects in natural foci.

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Relapsing fever- a group of acute infectious transmissible human diseases caused by Borrelia. It is characterized by bouts of fever followed by periods of apyrexia. Transmitted by lice or ticks.

relapsing fever

Relapsing fever (other names are epidemic relapsing fever, relapsing fever, epidemic relapsing spirochetosis, louse-borne relapsing fever). Relapsing fever lice - anthroponosis, transmitted by lice, manifested by intoxication, enlargement of the spleen and liver, alternation of 2-3 or more febrile attacks with fever-free intervals.

ICD code -10

A68.0. Headache relapsing fever.

Etiology (causes) of lice typhus

The causative agent of lice typhus is the spirochete Borrelia recurrentis Obermeieri (Obermeyer's spirochete) of the family Spirochaetaceae, genus Borrelia, shaped like a filiform spiral with 6–8 curls; has active mobility; anaerobe. Reproduces by transverse division. It stains well with aniline dyes, gram-negative. Spirochete grows on special nutrient media.

The number of Borrelia protein antigens reaches several tens, their synthesis is encoded by different genes, some of which are periodically in an inactive "silent" form. During the disease, due to rearrangements in the chromosome, the “silent” gene is activated and the generation of Borrelia with a new antigenic composition appears.

Obermeier's spirochete contains endotoxins. Pathogenic for monkeys, white mice and rats; not pathogenic for guinea pigs.

B. recurrentis is not stable in the environment, it quickly dies when dried and heated to 50 °C. Sensitive to benzylpenicillin, tetracyclines, chloramphenicol, erythromycin.

Epidemiology of lice typhus

Source of infection- sick person. The chance of infection increases during bouts of fever. The carrier of Borrelia is the louse (mainly body louse, less often the head louse), which can transmit the infection 6–28 days after it feeds on the blood of a sick person. Spirochetes multiply and accumulate in the hemolymph of the louse. Infection of a person occurs when the hemolymph of a crushed louse gets on damaged skin (combing, rubbing with clothes).

Body louse - a carrier of infection

Susceptibility people to this infection is absolute.

Immunity after suffering lice relapsing fever, it is unstable, repeated diseases are possible.

In the past, relapsing fever was widespread in many countries of the world, the incidence increased sharply during wars, famines and other socio-economic disasters. During the First and Second World Wars, epidemics were observed everywhere. In Russia, lice relapsing fever was completely eliminated in the middle of the last century, but the possibility of importing this disease into our country from endemic regions cannot be ruled out: some countries of Asia, Africa, Central and South America. Characterized by seasonality with an increase in incidence in the winter-spring period.

The pathogenesis of lice typhus

Borrelia that have penetrated the skin into the human body are captured by the cells of the histiophagocytic system and multiply in them - this phase corresponds to the incubation period of typhoid fever. Then the pathogen enters the bloodstream - borreliemia develops, manifested by the following symptoms: chills, fever, etc. After a few days, antibodies are produced that inactivate borreliae. Microbes are not found in the peripheral blood, the fever stops. As a result of the death of spirochetes, endotoxin is released, which acts on the cells of the endothelium of blood vessels, the liver, and the spleen, causing a violation of thermoregulation and microcirculation.

The accumulation of Borrelia in small vessels leads to the development of thrombosis, hemorrhage, DIC. Borreliemia and toxinemia manifest with the first febrile attack, after which some of the spirochetes remain in the central nervous system, bone marrow, and spleen. They multiply and a few days after the temperature returns to normal, they again enter the bloodstream, causing a second febrile attack. The new generation of Borrelia differs in the structure of antigens from the previous one, therefore the pathogen is resistant to the antibodies formed during the first attack, but is destroyed by phagocytes and antibodies produced during the second attack. This process is repeated until the patient has antibodies to all generations of Borrelia.

Pathological and anatomical changes in those who died from typhoid fever are found primarily in the spleen, liver, brain, and kidneys.

The spleen can be enlarged 5-8 times, its capsule is tense, easily torn; in the parenchyma, hemorrhages, heart attacks, foci of necrosis are detected, in the vessels - thrombosis, a large number of borrelia. Foci of necrosis are found in the liver.

In the brain, vasodilatation, hemorrhages, and perivascular infiltrates are detected.

Clinical picture (symptoms) of typhoid fever

The incubation period is from 3 to 14 (average 7–8) days.

Typhus classification

Clinical classification provides for the allocation of erased, mild, moderate, severe forms of typhoid fever. The severity criteria are the height and duration of fever, the severity of intoxication, the intensity of hemodynamic disorders.

The main symptoms and dynamics of their development

The vast majority of cases of typhoid fever are characterized by a violent, sudden onset with a tremendous chill, which after a few hours is replaced by fever and a rapid increase in body temperature to 39-40 ° C and above. Occasionally, the disease begins with a prodromal period, during which general weakness, fatigue, headaches and joint pains appear.

Already on the first day there is a severe headache, aching muscles (especially calf), lower back, joints, photophobia, insomnia. Loss of appetite, nausea, vomiting, thirst may occur. Patients become lethargic, lethargic, some show meningeal symptoms. There is an injection of the sclera, hyperemia of the conjunctiva. Possible nosebleeds, petechial rash, hemoptysis. From the second day of illness, the spleen enlarges, which causes a feeling of heaviness, pressure or dull pain in the left hypochondrium.

From the 3-4th day, yellowness of the skin and sclera appears, the liver enlarges. Typical shortness of breath, tachycardia up to 140-150 per minute, lowering blood pressure. The tongue is dry, densely coated with white coating, acquires a "milky", "porcelain" appearance.

Diuresis is reduced.

Hyperthermia in typhoid fever persists for 5-7 days, after which the body temperature drops critically to subnormal, which is accompanied by heavy sweating and often a sharp drop in blood pressure up to collapse. The duration of the first attack ranges from 3 to 13 days. During the "crisis" up to 3-4.5 liters of light urine is released.

After the temperature normalizes, the patients feel better, the pulse slows down, but severe weakness persists.

The disease may be limited to one febrile attack (especially with early antibiotic treatment). In most patients, after 7–10 days of apyrexia, the body temperature suddenly rises again and a second febrile attack occurs, similar to the first, but shorter (3–4 days), although often more severe.

rice. 9-1g Temperature curve of fever in typhoid fever

In more than half of the cases, the disease ends with a second attack. Sometimes after 9–12, extremely rarely - 20 days after the next period of normal temperature, a third attack occurs, even shorter and lighter. In total, 4–5 febrile attacks are possible, with each of the subsequent ones being shorter than the previous one, and the periods of apyrexia becoming longer. Early initiation of etiotropic therapy reduces the number of seizures.

In typical cases, the temperature curve is so characteristic that it is she who makes it possible to suspect relapsing fever.

The period of convalescence is long, the state of health of patients is restored slowly, within a few weeks after the final normalization of temperature, general weakness, fatigue, dizziness, and insomnia persist.

Complications of lice typhus

Specific complications, as with other spirochetosis, are meningitis, encephalitis, iritis, iridocyclitis. The most severe, but rare complication requiring urgent surgical intervention is rupture of the spleen. Nasal and uterine bleeding, hemorrhage in the brain and other organs are also possible. A critical decrease in body temperature by 4–5 °C may be complicated by collapse.

Mortality and causes of death

Mortality with timely antibacterial treatment is about 1% (in the past it reached 30%).

Diagnostics

Diagnosis is based largely on data from an epidemiological history - staying in an area where louse relapsing fever occurs. During the first attack, the main symptoms are taken into account: the most acute onset of the disease, hyperthermia from the very first hours, severe pain (headache, muscle pain), early enlargement and soreness of the spleen and liver, subicteric skin and sclera. In subsequent attacks, the typical appearance of the temperature curve helps the diagnosis.

The most informative method of specific laboratory diagnostics is the detection of Obermeier's Borrelia in peripheral blood during fever (rarely during apyrexia). A smear and a thick drop of blood are examined, stained according to Romanovsky-Giemsa (as in malaria).

In a clinical blood test, moderate anemia, thrombocytopenia, an increase in ESR, a normal or slightly elevated white blood cell count are noted. In the urine, a small amount of erythrocytes, protein, hyaline cylinders are found.

Differential Diagnosis

Differential diagnosis is carried out with malaria, tick-borne relapsing fever, leptospirosis, influenza, typhus, meningitis, pneumonia, HL.

Mistakes can be avoided by taking into account the details of the epidemiological history (staying at times corresponding to the duration of the incubation period in the area where relapsing fever occurs), repeated attacks of fever and the results of a thorough examination of blood smears in patients who fell ill suddenly, with high fever, severe symptoms intoxication, rapid and significant enlargement of the spleen and its soreness.

Indications for consulting other specialists

Consultations of other specialists are indicated in case of complications: if a rupture of the spleen is suspected, an urgent consultation with a surgeon is necessary; with the appearance of signs of ITSH - resuscitator.

Diagnosis example

A68.0. Epidemic relapsing fever, severe form (in a blood smear of Obermeier's spirochete). Complication: rupture of the spleen.

Treatment of lice typhus

Mode. Diet

Patients with relapsing fever must be hospitalized. Strict bed rest is required until stable normalization of body temperature.

Medical treatment

It is carried out within 7-10 days with one of the antibiotics acting on Borrelia. Tetracyclines are considered the drugs of choice: doxycycline 100 mg twice a day or tetracycline 0.5 g four times a day.

Alternative antibacterial drugs include erythromycin at a daily dose of 1 g and benzylpenicillin at 2 million–3 million IU/day intramuscularly.

At the same time, infusion detoxification therapy is prescribed.

It should be borne in mind that after the start of antibiotic treatment (especially benzylpenicillin), a Jarisch-Gersheimer exacerbation reaction is possible.

Convalescents are discharged from the hospital no earlier than 3 weeks after the final normalization of body temperature.

Forecast

The prognosis is favorable with the early appointment of specific therapy. Unfavorable prognostic signs are intense jaundice, massive bleeding, and cardiac arrhythmias.

Prevention of lice typhus

Specific prophylaxis has not been developed. The fight against pediculosis, early detection and isolation of patients, their urgent hospitalization and chamber disinfection of things, sanitization of contact persons, who are medically monitored with daily thermometry for 25 days after the patient's hospitalization.

Relapsing fever is a concept that includes several diseases similar in their mechanism of development and clinical course, namely lousy and tick-borne typhus. Despite this, both pathologies are considered independent diseases.

The main causative agent of the disease is considered to be such a pathogen as a spirochete, and human infection occurs from an infected insect. It is noteworthy that the carrier of the bacterium will be dangerous to humans throughout its entire life cycle.

The most characteristic clinical signs of the disease are recurrent bouts of fever accompanied by severe headaches, nausea and vomiting, and delirium.

It is impossible to make a correct diagnosis based on symptoms alone. This requires laboratory blood tests, during which particles of the pathogen will be detected.

Treatment of such a disease is only conservative and is limited to taking antibacterial drugs.

Etiology

Depending on the form of pathology, spirochete always acts as the causative agent of relapsing fever. The culprit of the disease has the following symptoms:

• spiral shape;
• increased mobility;
• length varies from ten to thirty micrometers;
• thickness - up to 0.5 µm.

The source of infection is an infected person, who is especially dangerous during periods of exacerbation of symptoms. In this case, the concentration of spirochetes in the blood reaches its maximum.

The carriers of the pathogen are either lice or ticks, which causes the presence of several varieties of the disease. After the insects drink the infected blood, the spirochetes enter the body of the carrier, where they remain until the end of his life.

A healthy person can become infected in only one way - in cases of crushing an infected insect, which is why spirochetes are released with his blood. They can enter the body only through damaged skin from abrasions, scratches or scratches.

In addition, it is worth highlighting the main risk groups, which include people:

• living in unfavorable sanitary conditions;
• with a weak immune system;
• where the trigger is located.

In addition, there is a seasonality in the incidence - most often the disease is diagnosed in the hot season, when insects are more active.

Classification

Depending on the carrier of spirochetes, the disease is divided into:

• lousy relapsing fever- Often, lice, in particular body lice, pubic or head lice, act as reservoirs for the reproduction and vital activity of bacteria. A distinctive feature is that it is this type of disease that can take on epidemic proportions, which is why it is also widely known as epidemic relapsing fever;
• tick-borne relapsing fever- very often, human infection occurs during the bite of an infected insect. It is noteworthy that spirochetes remain in ticks not only until the end of their lives, but can also be transmitted to descendants. The causative agents of this variant of the course of relapsing fever remain in the human body both during a febrile attack and after it. A similar type of pathology in the medical field has a second name - endemic relapsing fever.

Symptoms

The clinical manifestation of the disease will differ somewhat depending on the bite of which insect served as the beginning of the development of the infectious process.

Thus, epidemic relapsing fever is characterized by the following features:

• the duration of the incubation period varies from three days to two weeks;
• sudden increase in body temperature, up to 40 degrees;
• alternating chills and heat;
• severe weakness of the body;
• lack of sleep;
• pronounced headaches;
• soreness and weakness of the joints;
• pathological reddening of the skin of the face;
• rashes on the skin like roseola, petechiae or macules;
• hemorrhages from the nasal cavity;
• - in this case, there is a simultaneous increase in such organs as the spleen and liver;
• the acquisition of a yellowish tint by the skin and sclera - such a symptom occurs approximately on the second day of the course of the disease;
• nausea, accompanied by frequent vomiting;
• stool disorder, which is expressed in diarrhea - feces may have pathological impurities of pus;
• decrease in the daily volume of urine emitted.

The duration of an attack with the presence of such signs can be from two to six days. After this, there comes a time for the retreat of symptoms for an average of ten days.

Loicey relapsing fever very often goes away on its own, after a few bouts of renewed fever. At the same time, people who have had this type of disease develop immunity for a while.

The symptom complex of tick-borne relapsing fever includes:

• the duration of the incubation period is from five to fifteen days;
• the formation of a small papule at the site of an insect bite;
• an increase in temperature up to 39 degrees;
• headaches and dizziness;
• body - this should include nausea, vomiting and diarrhea;
• sleep disorder;
• delirium;
• lack of appetite;
• increased sweating.

A feverish state is observed for four days, after which the temperature decreases and the person's condition improves, which indicates the beginning of the period of apyrexia, i.e., relief of symptoms.

The fever-free period for each patient lasts differently - for some no more than two days, for others - for four weeks. The maximum number of attacks is ten times. Despite this, endemic relapsing fever is tolerated by people much easier than the epidemic form, and after recovery, long-term immunity is formed.

Diagnostics

Since both varieties of relapsing fever have almost the same symptoms, the diagnosis is made on the basis of laboratory blood tests. Nevertheless, it is necessary to carry out primary diagnostic measures, which include:

• study of the patient's life history;
• a thorough physical examination aimed at palpation of the anterior abdominal wall, which will help to identify hepatosplenomegaly, examination of the condition of the skin and visible mucous membranes, as well as temperature measurement;
• a detailed survey of the patient - to determine the duration of the attack and the severity of symptoms. This will make it possible to distinguish tick-borne relapsing fever from lousy.

The basis of diagnosis is a general clinical and biochemical blood test, which are carried out:

• at the peak of an attack of fever - to identify the epidemic type of the disease;
• in the fever-free period - to confirm the diagnosis of endemic relapsing fever.

Additional studies include:

• complement fixation reactions and platelet loading of spirochetes;
• precipitation reaction;
• serological studies;
• PCR tests;
• biological sample - for this, the patient's blood is transfused into guinea pigs and the reaction is observed.

Instrumental examinations for relapsing fever have no diagnostic value.

Differential diagnosis is to distinguish such a disease from such pathologies:

Treatment

Therapy of such a disease is etiotropic in nature and consists in eliminating the causative agent of the disease. For this, patients are shown taking medications, which will differ depending on the form of the disease.

Thus, the therapy of lousy relapsing fever is aimed at using:

• "Levomycetin";
• "Penicillin";
• "Chlortetracycline";
• "Novarsenol".

The first three substances are antibiotics, and the last one is an arsenic preparation.

Elimination of tick-borne relapsing fever involves taking:

• antibacterial agents of the tetracycline category;
• "Levomycetin";
• "Ampicillin".

In cases of a severe course of the disease, detoxification therapy is additionally prescribed, which is carried out in a hospital.

Possible Complications

If symptoms are ignored and treatment is not started in time, each of the varieties of the disease can lead to serious complications.

Louse relapsing fever is fraught with:

• internal bleeding, which is most often formed due to rupture of the spleen;
• bilious typhoid;
• focal pneumonia.

In pregnant women, the disease can lead to:

• early labor activity;
• spontaneous abortion;
• uterine hemorrhage.

Among the consequences of endemic relapsing fever are:

• iridocyclitis;

Prevention and prognosis

There are no specific preventive measures to prevent the development of relapsing fever. However, to reduce the risk of its occurrence, it is recommended:

• take measures regarding the destruction of lice and ticks;
• wear protective clothing when outdoors for a long time;
• use special substances aimed at the destruction of insects;
• avoid contact with an infected person.

Relapsing fever of lousy and tick-borne forms often has a favorable prognosis. Complications develop quite rarely, but the likelihood of recurrence of the disease is high.

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Relapsing fever is a collective term used in the field of infectious diseases, combining epidemic relapsing fever, which is carried by the louse, and endemic relapsing fever, which is carried by the tick. All spirochetosis proceed paroxysmal with alternation of a sharp rise in body temperature and normalization of the temperature reaction, which is a pathognomonic sign of this disease.

Tick ​​relapsing is distributed everywhere, except for villages in Australia, and is observed in the form of sporadic, epidemic or endemic outbreaks. The peak incidence of relapsing fever is observed in Africa, in addition, in this region, typhus occurs exclusively in a severe complicated form. The maximum mortality rate from relapsing fever was observed during the First World War in the regions of Sudan, where up to 10% of the population suffered from this infectious pathology.

Also, epidemic relapsing fever spread through the cities of India, Russia and the countries of the Balkan Peninsula. Fortunately, in Europe and the United States, only endemic relapsing fever is observed, which occurs in a mild form, which is due to the high level of sanitary and hygienic awareness of the population. The rapid spread of relapsing fever is facilitated by overcrowding and unsanitary conditions. African and Asian countries are most affected by epidemic relapsing fever, which is transmitted by lice, while regions of North America, including Mexico, have a high incidence of tick-borne relapsing fever.

The pathogenesis of the development of relapsing fever starts from the moment Borrelia enters the human body, which are actively introduced into macrophages and lymphocytes, where they actively multiply and enter the general circulation in a huge amount. Since the blood has some bactericidal properties, there is a partial destruction of borreliae, which is accompanied by the release of endotoxin, which has a damaging effect on the structures of the circulatory and central nervous system. The intoxication mechanism is manifested by the appearance of fever, foci of necrosis in the parenchyma of the spleen and liver. Under the influence of antibodies that are actively produced by the human immune apparatus in response to the entry of Borrelia into the blood, aggregates of pathogens are formed that linger in the microvasculature of the internal organs, thereby provoking the development of circulatory disorders leading to the formation of hemorrhagic microinfarcts.

The first episode of fever in relapsing fever is accompanied by the development of a powerful immune response, which provokes the mass death of pathogens, which manifests itself clinically in the form of a short period of remission. The rest of the borrelias change their antigenic properties, which is accompanied by an increase in their resistance to antibodies, so they continue to actively multiply and penetrate into the general bloodstream, thereby provoking the development of a new attack of fever. There may be several such relapses during the development of the disease, and recovery is possible only when the human body begins to produce the entire spectrum of antibodies that effectively lyse all the antigenic compositions of Borrelia. Developed antibodies against Borrelia remain for a short time in the human body, so the same person can suffer from this infectious disease several times during his life.

The causative agent of relapsing fever

Tick-borne relapsing fever is a representative of obligate-transmissible infectious diseases and the carrier of relapsing fever in this situation is represented by the Argasidae tick, which has several varieties (Ornitodorus papillare, Argas persicus). Ticks in relapsing fever should be considered as a reservoir host for spirochetes, which are the direct causative agents of the disease. Also, wild rodents can act as a natural reservoir of Borrelia in natural foci. The pathogenicity of ticks infected with spirochetes persists for decades.

Also, any arthropod containing a spirochete in the oviduct can be a carrier of relapsing fever. Under natural conditions, there is a continuous circulation of Borrelia from rodents to carriers of the disease and vice versa.

Infection of a person with tick-borne relapsing fever occurs with a direct bite of an infected tick, where a primary affect in the form of a papule forms on the skin. The peak incidence of tick-borne relapsing fever falls on warm seasons, which is due to the activation of vital processes of spirochete carriers.

Persons living in areas endemic for the development of tick-borne relapsing fever for a long time become immune to the pathogens of this disease over time, as their bodies gradually develop an immune response in the form of antibodies to borrelia, which are common in this region.

The carrier of relapsing fever, proceeding according to the epidemic variant, is lice of various species (Pediculus humanus capitis, P. humanus humanus and Phtirius pubis). Infected lice are contagious to humans throughout their life, due to the absence of pathogenicity of borrelia in relation to lice, as well as the ability of pathogens to actively multiply in the hemolymph of insects. Transovarial transmission of borrelia in lice does not occur under any circumstances. Infection of a person with borrelia in epidemic relapsing fever occurs when the hemolymph of infected lice is rubbed into the skin, which occurs when the insect is crushed or the bite site is combed. Under environmental conditions, Borrelia persist for a very short period of time, as they are detrimental to both high and low temperatures, ultraviolet radiation and exposure to disinfectants. Epidemic relapsing fever occurs exclusively among people of different age categories.

Symptoms and signs of relapsing fever

Objective signs of relapsing fever in the early period is the detection of a sharp flushing of the skin on the face, which on the fourth day acquires a lemon icteric color. On the part of the activity of the cardiovascular system, the appearance of tachycardia, hypotension is noted. The respiratory system is forced to function in a compensatory mode, which is manifested by tachypnea.

A pathognomonic clinical marker of relapsing fever is the formation of a recurrent tongue, the surface of which becomes sharply moist, somewhat swollen, covered with a thick white coating, easily removed with a spatula and quickly formed again.

Palpation with relapsing fever can determine hepatosplenomegaly, which develops already at an early stage of the disease. The duration of the first episode of hectic fever averages five days, after which the patient develops severe hyperhidrosis with concomitant arterial hypotension and normalization of the temperature reaction. The duration of the “period of imaginary well-being” with relapsing fever is an average of six days, during which the patient stops intoxication, improves appetite and self-cleansing of the surface of the tongue.

In some patients, relapsing fever manifests itself with only one episode of fever, however, subject to the timely provision of medical care to such patients, the development of repeated attacks is noted, which are more severe than the previous one. The multiplicity of periods of exacerbation in relapsing fever is two to three attacks. Repeated attacks of fever with relapsing fever are often accompanied by the development of complications, manifested in the form of rupture of the spleen, collapse, nosebleeds.

The most severe complication of relapsing fever is the formation of infarction zones in the spleen parenchyma, which can provoke the development of severe intracavitary bleeding. The septic course of relapsing fever is accompanied by the formation of multiple foci of septicopyemia. At present, fortunately, there is a favorable course of relapsing fever, and the mortality rate from complications does not exceed 1%.

Diagnosis of relapsing fever

The most reliable are bacteriological methods for detecting a pathogen in the form of Romanovsky-Giemsa staining of a thick blood smear with further microscopy. The mobility of Borrelia is assessed under a microscope in a dark field, and a drop of blood serves as the material for the study. Serological research methods in the form of a complement fixation test also have a high rate of reliability, although the complexity of their implementation and the long time to obtain results limit the use of these methods for laboratory diagnosis of relapsing fever.

Separation of epidemic and endemic variants of relapsing fever in the laboratory is carried out by a biological method using laboratory animals. The blood of a person infected with Borrelia is injected into a guinea pig. So, borrelia, which provoke epidemic relapsing fever, do not have a pathological effect on animals. In a situation where the patient is sick with tick-borne relapsing fever, the infected guinea pig will show clinical signs of relapsing fever after seven days.
Treatment of relapsing fever

For drug therapy of relapsing fever, preference should be given to the appointment of antibacterial drugs lasting at least ten days. The gold standard in the medical treatment of relapsing fever is the appointment of antibacterial agents of the tetracycline series (Doxycycline at a daily dose of 0.2 g, Tetracycline at a daily dose of 2 g parenterally). In the absence of a positive effect from the use of these antibiotics, which under normal conditions are observed on the second day of their use, therapy should be supplemented with the appointment of Erythromycin 500 mg twice a day, as well as Benzylpenicillin at a daily dose of 2 million IU parenterally. The use of the above antibacterial agents in some patients provokes the development of the Jarisch-Gersheimer reaction, which is manifested by an increase in the intoxication syndrome and requires immediate detoxification measures.

Equally important in the treatment of patients suffering from relapsing fever is the use of drug detoxification measures using intravenous drip of crystalloid solutions (Reopoliglyukin in a volume of 300 ml). Discharge of patients from the infectious diseases hospital should be carried out no earlier than three weeks after the start of the antipyrexic period. In a situation of timely started drug treatment, the course of relapsing fever is favorable and the prognosis for recovery is also favorable. Unfavorable prognostic criteria are increasing jaundice, the appearance of massive hemorrhagic manifestations in the form of intense bleeding and cardiac dysfunction. Unfortunately, methods of specific prevention of relapsing fever have not been developed to this day. As preventive measures, only the fight against pediculosis, as well as the observance of quarantine measures in identifying patients, should be considered.

Relapsing fever - which doctor will help? If there is or suspected the development of relapsing fever, you should immediately seek advice from such doctors as an infectious disease specialist, therapist.

) spirochetosis, occurring with alternating bouts of fever and periods of normal body temperature.

History of the concept

Before the development of microbiology, these diseases were combined with other infectious diseases, accompanied by a "clouding" of consciousness, under the general name typhus. As separate types of this disease, epidemic typhus (carried by lice) and endemic tick-borne typhus are distinguished.

Epidemiology

Pathogens and vectors

The causative agents of relapsing fever are spirochetes of the genus Borrelia, in particular, one of the most common pathogens of epidemic typhus is Borrelia Obermeyer ( Borellia recurrentis), discovered in 1868 by Otto Obermeier.

Tick-borne relapsing fever is a zoonotic vector-borne disease. The causative agents are many types of Borrelia: B. duttonii, B. crocidurae, B. persica, B. hispanica, B. latyschewii, B. caucasica common in certain geographic areas. These borrelia are similar to the causative agent of epidemic relapsing fever in morphology, resistance to environmental factors, and biological properties.

carriers

A person becomes infected by tick bites. At the site of inoculation of the pathogen, a papule is formed (primary affect). The pathogenesis and clinical manifestations of tick-borne relapsing fever are similar to epidemic. Diseases often occur in the warm season with the activation of the vital activity of ticks.

The population of areas endemic for tick-borne relapsing fever acquires a certain degree of immunity to circulating pathogens - they have antibodies to borrelia common in this region in their blood serum. It is mainly visitors who get sick.

Carriers of epidemic relapsing fever - lice Pediculus humanus capitis(head), P. humanus humanus(dress). The louse, having sucked the patient's blood, becomes capable of infecting a person throughout its life, since borrelia are non-pathogenic for lice, and microorganisms multiply well in the insect's hemolymph. There is no transovarial transmission of Borrelia in lice. A person becomes infected by rubbing lice hemolymph containing borrelia (when combing a bite, crushing an insect) (contaminative infection). In the environment, Borrelia quickly die. Under the action of a temperature of 45-48 ° C, death occurs after 30 minutes. Epidemic relapsing fever only affects humans.

Course of the disease. Pathogenesis

Once in the internal environment of the body, Borrelia invade the cells of the lymphoid-macrophage system, where they multiply, and then enter the blood in larger quantities. Under the influence of the bactericidal properties of blood, they are partially destroyed and endotoxin is released, damaging the circulatory and central nervous system. Toxicosis is accompanied by fever, and foci of necrosis appear in the spleen and liver. Due to the aggregates from borrelia formed under the influence of antibodies, which linger in the capillaries of internal organs, local blood supply is disrupted, which leads to the development of hemorrhagic infarcts.

The first febrile period of the disease ends with the formation of antibodies against the first generation Borrelia. Under the influence of these antibodies, microbial aggregates arise with a load of platelets and most of the Borrelia die. Clinically, this is expressed by the onset of remission. But some of the pathogens change their antigenic properties and become resistant to the formed antibodies, and subsequently remain in the body. This new generation of borrelias multiplies and, flooding the bloodstream, gives a new attack of fever. The resulting antibodies against the second generation of the pathogen lyse a significant part of them, but not completely. Resistant pathogens that have changed antigenic specificity, multiplying, again give a relapse of the disease. This is repeated several times. Recovery occurs only when a spectrum of antibodies appears in the blood, lysing all antigenic variants of Borrelia.

The transferred disease does not leave strong immunity. The formed antibodies remain for a short time.

Clinical picture

The first attack begins suddenly: a short chill is replaced by fever and headache; there are pains in the joints and muscles (mainly calf), nausea and vomiting. The temperature rises quickly, the pulse is frequent, the skin is dry. The nervous system is involved in the pathological process, delirium often occurs. At the height of the attack, various forms of rash appear on the skin, the spleen and liver increase, and jaundice sometimes develops. During a fever, there may be signs of heart damage, as well as bronchitis or pneumonia. The attack lasts from two to six days, after which the temperature drops to normal or subfebrile and the patient's health improves rapidly. However, after 4-8 days, the next attack develops with the same symptoms. Cases without recurrences are rare.

For louse relapsing fever, one or two repeated attacks are characteristic, which end in complete recovery and temporary immunity. Tick-borne relapsing fever is characterized by four or more attacks of fever, they are shorter and milder in clinical manifestations, although the second attack may be more severe than the first.

Laboratory diagnostics

During an attack, at the height of the fever, the pathogen can be relatively easily detected in the patient's blood. To do this, preparations of a thick drop or blood smear are prepared, stained according to Romanovsky - Giemsa or magenta and microscoped. It is possible to microscope blood drops in a dark field, observing the mobility of Borrelia. The method of serological diagnostics consists in the formulation of lysis reactions, RSK.

Differentiation of epidemic from endemic relapsing fever is carried out in a biological experiment: a guinea pig is injected with the patient's blood. Borrelia of epidemic relapsing fever, unlike endemic ones, do not cause disease in the animal. With tick-borne typhus, the mumps falls ill for 5-7 days, and borrelia are found in its blood.

Prevention

Prevention of epidemic typhus is reduced to the fight against lice, avoiding contact with lice patients. At present, epidemic relapsing fever does not occur in Russia and in many other countries. Prevention of tick-borne relapsing fever is to protect people from tick attacks, the destruction of rodents and insects in natural foci.

Treatment

Antibiotics (penicillin, levomycetin, chlortetracycline) and arsenic preparations (novarsenol) are used to treat epidemic relapsing fever. In the treatment of tick-borne typhus, tetracycline antibiotics, levomycetin, and ampicillin are used.

Forecast

In most parts of the world, with the exception of some countries in Central Africa, relapsing fever is rarely fatal, especially in healthy, well-nourished people. Epidemics of relapsing fever among weakened groups of the population in conditions of poor medical care can be accompanied by high mortality among the sick - up to 60-80%. Complications of relapsing fever include myocarditis and inflammatory eye lesions, heart attacks and abscesses of the spleen, dermatitis, pneumonia, temporary paralysis and paresis, a variety of mental disorders from twilight consciousness to manic states.

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An excerpt characterizing relapsing fever

When Pierre, having run around the yards and lanes, went back with his burden to the Gruzinsky garden, on the corner of Povarskaya, for the first minute he did not recognize the place from which he went for the child: it was so cluttered with people and belongings pulled out of the houses. In addition to Russian families with their belongings, who were fleeing the fire here, there were also several French soldiers in various attire. Pierre ignored them. He was in a hurry to find the official's family in order to give his daughter to his mother and go again to save someone else. It seemed to Pierre that he still had a lot to do and that he needed to do it as soon as possible. Inflamed with heat and running around, Pierre at that moment, even stronger than before, experienced that feeling of youth, revival and determination that seized him while he ran to save the child. The girl calmed down now and, holding on to Pierre's caftan with her hands, sat on his arm and, like a wild animal, looked around herself. Pierre glanced at her from time to time and smiled slightly. It seemed to him that he saw something touchingly innocent and angelic in that frightened and sickly little face.
In the same place, neither the official nor his wife was gone. Pierre walked with quick steps among the people, looking at the different faces that came across to him. Involuntarily, he noticed a Georgian or Armenian family, consisting of a handsome, oriental-faced, very old man, dressed in a new indoor sheepskin coat and new boots, an old woman of the same type, and a young woman. This very young woman seemed to Pierre the perfection of oriental beauty, with her sharp, arched black eyebrows and a long, unusually tenderly ruddy and beautiful face without any expression. Among the scattered belongings, in the crowd in the square, she, in her rich satin coat and bright purple shawl that covered her head, resembled a tender hothouse plant thrown into the snow. She was sitting on knots a little behind the old woman and motionlessly with large black oblong eyes with long eyelashes looked at the ground. Apparently, she knew her beauty and was afraid for her. This face struck Pierre, and in his haste, passing along the fence, he looked back at her several times. Having reached the fence and still not finding those whom he needed, Pierre stopped, looking around.
The figure of Pierre with a child in her arms was now even more remarkable than before, and several people of Russian men and women gathered around him.
“Or did you lose someone, dear man?” Are you one of the nobles yourself? Whose child is that? they asked him.
Pierre answered that the child belonged to a woman and a black coat, who sat with the children in this place, and asked if anyone knew her and where she had gone.
“After all, it must be the Anferovs,” said the old deacon, turning to the pockmarked woman. “Lord have mercy, Lord have mercy,” he added in his usual bass.
- Where are the Anferovs! - said the grandmother. - The Anferovs left in the morning. And this is either Marya Nikolaevna or the Ivanovs.
- He says - a woman, and Marya Nikolaevna - a lady, - said the courtyard man.
“Yes, you know her, her teeth are long, thin,” said Pierre.
- And there is Marya Nikolaevna. They went into the garden, when these wolves swooped in, - said the woman, pointing to the French soldiers.
“Oh, Lord have mercy,” added the deacon again.
- You go here and there, they are there. She is. She was still crying, she was crying, - the woman said again. - She is. Here it is.
But Pierre did not listen to the woman. For several seconds he had been staring at what was happening a few steps away from him without taking his eyes off him. He looked at the Armenian family and the two French soldiers who had approached the Armenians. One of these soldiers, a small fidgety little man, was dressed in a blue overcoat, belted with a rope. He had a cap on his head and his feet were bare. The other, who especially struck Pierre, was a long, round-shouldered, blond, thin man with slow movements and an idiotic expression. This one was dressed in a frieze hood, blue trousers and large torn over the knee boots. A little Frenchman, without boots, in blue, hissed, approaching the Armenians, immediately, saying something, took hold of the old man's legs, and the old man immediately began hastily taking off his boots. The other, in the hood, stopped in front of the beautiful Armenian woman and silently, motionless, holding his hands in his pockets, looked at her.
“Take, take the child,” Pierre said, giving the girl and imperiously and hastily addressing the woman. Give them back, give them back! he almost shouted at the woman, putting the screaming girl on the ground, and again looked back at the French and the Armenian family. The old man was already sitting barefoot. The little Frenchman took off his last boot and patted his boots one against the other. The old man, sobbing, said something, but Pierre only glimpsed it; all his attention was directed to the Frenchman in the bonnet, who at that moment, slowly swaying, moved towards the young woman and, taking his hands out of his pockets, took hold of her neck.
The beautiful Armenian woman continued to sit in the same motionless position, with her long eyelashes lowered, and as if she did not see and did not feel what the soldier was doing to her.
While Pierre ran those few steps that separated him from the French, a long marauder in a hood was already tearing the necklace that was on her from the neck of the Armenian woman, and the young woman, clutching her neck with her hands, screamed in a piercing voice.