Leptospirosis is an infectious disease, the source of which is sick animals. The disease can most often be contracted through open bodies of water contaminated with the pathogen. The disease is characterized by the development of fever, nausea, body aches, impaired formation of secondary urine, pathology of liver function, central nervous system and hemorrhages on the skin.

If medical care is not provided in a timely manner, the outcome of the disease is most often death.

Leptospirosis in humans, causes of the disease, treatment

Leptospirosis is the most common disease transmitted from animals to humans in the world. It is recorded everywhere except in deserts and permafrost areas. In the Russian Federation, about 1500–2000 cases are registered every year, which is a high figure due to the great danger of this disease for humans.

Leptospirosis is caused by a bacterium of the Spirochaetaceae family, genus Leptospira. This pathogen has several types of Leptospira, which can be divided into groups:

1. Pathogenic
2. Non-pathogenic saprophytes
3. With unknown pathogenicity

Leptospira have good survival in water (more than 200 days), in wastewater (up to 10 days), and can survive in moist soil from 43 to 280 days. Leptospira die in a dry environment, temperature 80-100°C, while low temperatures, on the contrary, contribute to the preservation and preservation of the bacterium. Almost all disinfectants have a detrimental effect on the viability of Leptospira.

The main natural reservoir of the pathogen is rodents, mammals, foxes, arctic foxes, and nutria. Penetration of the pathogen into the human body occurs most often through the fecal-oral route, through contaminated food, and dirty hands. People's susceptibility to the pathogen is high, because it can enter the human body through damaged skin or mucous membranes at any time of the year.

When Leptospira enters the body through the skin, pinpoint necrotic areas are quickly detected in the skeletal muscles. The same thing happens in the kidneys, and the tubular system is affected, which causes swelling of the tissues, decreased diuresis, as a result of a violation of the structure of the kidneys.

In the liver, swelling of parenchymal tissue and cell destruction occurs. This leads to retention of bile in the liver, changes in skin color and damage to the nervous system organs by metabolic products of the body, which accumulate due to liver pathology. Hemorrhages occur in the brain and lungs, which leads to severe pathology of the organ and disruption of its performance.

Treatment of the disease consists of prescribing specific antibacterial treatment, detoxification therapy and prevention of complications of the disease.

Leptospirosis in humans: symptoms and treatment

Water is the main source of leptospirosis both among people and among animals that come to drink and contaminate the water, then through this water other individuals, including humans, become infected.

The first symptoms of the disease appear after 2-26 days, on average 7-13 days. The duration of the incubation period depends on the microbial load on the body. Moreover, the more bacteria that enter the body, the faster the disease develops.

Leptospirosis is characterized by a two-phase course:

1. Leptospiremia - in this phase, leptospira can be detected in the blood and cerebral fluid during the first 4-9 days of the disease. The disease “Leptospirosis” in humans, symptoms and treatment (video and photo research reports) of this period of the disease were studied in detail only in the 80-90s of the last century. According to these studies, we can say that the disease begins suddenly, acutely. The first symptoms are most often a headache located in the frontal lobe or temples. Then comes aching pain in the muscles of the lower extremities and lower back. Very often, the onset of the disease is accompanied by chills and a rapid rise in body temperature to hectic levels (39.9 - 41°C). In this case, the duration of fever can last from 6 to 10 days. If during this period the patient does not receive antibiotic therapy, a second wave of fever may recur with severe damage to the muscular system of the human body and severe headache. 30% of patients experience jaundice of the skin and various rashes over the body, which most often disappear within 24-48 hours. Already on the 4-5th day of the disease, the “rabbit eye” symptom is noted, which is described as hemorrhage in the sclera and conjunctiva of the eye, which makes it bright red. It has been noted that prescribing antibiotics after 4-5 days of illness has virtually no therapeutic effect.
2. The height of the disease - this period is observed from the 14th to the 30th day of illness. This is characterized by the progression of organ damage, increased symptoms of intoxication (nausea, weakness, headache, elevated body temperature). Almost always there are hemorrhages in the skin and mucous membranes. In this case, there is a violation of the formation of secondary urine. Diuresis is less than 500 ml per day. Progressive renal failure is noted.

When examining the cardiovascular system, tachycardia and arrhythmia are noted. Severe forms of the disease are always accompanied by bleeding of various locations (uterine, intestinal, pulmonary). The most interesting thing is that the last stage of the disease “Leptospirosis” in humans, symptoms and treatment (video and photo research reports) were studied in detail much earlier than the first period of the disease.

This is due to the fact that the clinical symptoms of the second phase are more pronounced and noticeable to the naked eye, while the first stage, with a good state of the immune system, can only be diagnosed in a laboratory.

According to studies, Benzylpenicillin at a dosage of 500 thousand units 6 times a day or Doxycycline 100 mg IM 2 times a day for 7-10 days had a good therapeutic effect.

Leptospirosis in humans: symptoms and treatment, consequences of the disease

If medical care is not provided, each pathological symptom of the disease can cause a complication that threatens the quality and course of life:

• A decrease in the amount of urine excretion can lead to intoxication of the body with metabolic products, which will cause painful death or disability of the patient. In 80% of cases, patients undergo lifelong hemodialysis due to irreversible kidney damage.
• Yellowness of the skin leads to chronic liver damage, which over the next 5-6 years ends in cirrhosis and death within 10 years.
• Fever, nausea, muscle pain and other symptoms of intoxication if medical care is not provided can lead to organic damage to the brain with subsequent irreversible changes in its functioning.

In order to prevent serious complications of the disease, it is necessary to carry out thorough detoxification therapy with drug prevention of complications at all stages of the disease.

If symptoms of brain damage develop, it is necessary to increase the dose of Benzylpenicillin to 20 thousand units/kg body weight or replace the antibiotic with Chloramphinicol at 80-100 mg/kg body weight.

For allergic reactions to the penicillin series, Ceftriaxone is very effective at a dose of 2-4 g per day intravenously.

Leptospirosis in humans: symptoms and treatment for children

In childhood, leptospirosis has very difficult treatment due to the instability of the immune system. Therefore, at the first symptoms of the disease, children are immediately hospitalized in the intensive care unit, Ceftriaxone is prescribed in the maximum dose allowed for their age, powerful detoxification therapy is prescribed, and possible complications are prevented.

Leptospirosis is a very dangerous, transient infectious disease that is difficult to treat. Therefore, treatment at home can lead to a large number of complications and even death.

At the first symptoms of leptospirosis, you must immediately contact the nearest infectious diseases department to confirm or remove the diagnosis.

We live in close contact with the animal world and can no longer imagine our diet without meat products. Unfortunately, this is fraught with many dangers, including various pathologies, the carriers of which are all kinds of rodents and livestock. One of these diseases is leptospirosis, an acute infectious disease that leads to severe complications and even death.

Description of the disease and causative agent of leptospirosis

Leptospirosis is a very dangerous infectious disease that occurs in an acute form. The causative agent of the disease is the bacteria Leptospira interrogans (leptospira). Patients, as soon as possible after infection, begin to feel a severe deterioration in their health, characteristic rashes appear on the surface of the skin, and the functioning of the liver and kidneys is disrupted.

Leptospirosis is now considered by the World Health Organization to be one of the most common and serious diseases that can be contracted from animals, but outbreaks have been significantly reduced due to vaccination and rodent eradication. Before the introduction of these measures, the infection rate reached up to 7% of the entire population in some regions of the Russian Federation. The main surges occurred with an increase in the number of dogs in cities and the development of agriculture and animal husbandry. Currently, up to 3,000 cases per year are registered in the Russian Federation, especially in the North Caucasus region.

Most often, leptospirosis affects men from 18 to 40 years old. This is not associated with any features or differences in the structure of the body. The main reasons are lifestyle and professional activity.

Leptospirosis is an extremely life-threatening disease. In addition, it causes serious economic damage in those countries where epidemics are developing. The state incurs large losses, as farm animals suffer, milk yield decreases, and many livestock die. These factors stimulate scientists from all countries to improve methods of combating this disease and come up with new effective vaccines.

There are several synonyms for leptospirosis: Vasiliev-Weil disease, infectious jaundice, mowing meadow fever, Japanese 7-day fever, Boucher-Gsell disease. The first name is formed from the names of its discoverers, who described the disease in 1886 in Germany and 1888 in Russia independently of each other.

Pathogenesis of Vasiliev-Weil disease: causes of occurrence and routes of transmission of infection to humans

Leptospira bacteria belong to the class of spirochetes. There are a large number of its varieties, but Leptospira Interrogans are directly dangerous to humans.

Externally, this microorganism is a spiral-shaped thin ribbon, hence the name: leptos - small, spira - curl.

They are very mobile and move quickly in liquid and viscous media. They reproduce exclusively in conditions of high humidity (favorable environment - swamps, ponds, forests and fields), and die in dry climates. These bacteria are quite resistant to low temperatures, but do not tolerate heat above 30 0 C. Thanks to a special enzyme - fibrinolysin - leptospira thins human blood, which facilitates the rapid penetration of infection into the bloodstream.

You can get infected from various rodents that live at home or on the street. Sometimes foxes and arctic foxes become carriers.

Among domestic animals, leptospirosis can develop in cows, sheep, dogs, cats, and pigs.

Leptospires penetrate into the soil with the urine and excrement of animals, from where they can enter various bodies of water. Pathogenic bacteria are introduced into the human body mainly through food and water. First of all, they appear on the mucous membranes and skin, then through the blood or lymph flow they are spread throughout the body, where they multiply in various organs, after which they again enter the blood. It is this moment that is considered to be the beginning of the disease, after which the first symptoms appear.

There are several ways a person can become infected:

1. The contact route is the most common and is recorded in most patients. In this case, Leptospira enters the human body through small wounds and cuts on the skin and mucous membranes. Workers in agriculture and any other professions related to animals (toxidermists, shepherds, livestock specialists, veterinarians) are especially often infected in this way. The infection can also penetrate through broken skin and during bathing.
2. The alimentary route involves Leptospira entering the human body through the mouth and gastrointestinal tract. You can become infected by drinking water or eating contaminated food.
   

   Pathogenic microorganisms can survive for a long time on vegetables and fruits that have been sprayed with water from open reservoirs. In addition, leptospira can be found in the meat and milk of infected animals. Bacteria die after heat treatment.

3. The aspiration route of infection involves aspiration (the penetration of water into the respiratory tract during inhalation) through the nasopharynx or oral cavity. The fact is that open reservoirs, especially with stagnant water, are often infected with Leptospira due to the urine and feces of animals.
4. The transmission route is the rarest. In this case, the infection enters the body due to the bite of ticks or lice, which act as a carrier. In this case, leptospires penetrate directly into the bloodstream.

During illness, a person does not pose a danger to others; he is not contagious.

Characteristic symptoms of mowing meadow fever in adults and children: rash, kidney damage, etc.

The main symptoms in patients arise from substances that the bacterium secretes during its life. They greatly affect a person’s well-being and health, leading to extremely serious consequences.

After the collapse of Leptospira, they release a special endotoxin that affects the epithelium of the vascular walls, which provokes the destruction of capillaries. It is for this reason that small bruises appear on the surface of the skin of those infected. Also, small hemorrhages can occur throughout the body; outwardly this can be noticeable on the whites of the eyes, which take on a red tint.

In addition to compromising the integrity of blood vessels, endotoxin leads to a strong increase in body temperature. This is the first symptom of the disease, which is detected already on the second day of the disease.

The more bacteria in the body, the higher the temperature will rise, reaching 40 0 ​​C.

After ten days, the temperature may drop sharply to normal values, which does not indicate an improvement in the condition. Muscle pain is very common. Toxins also cause fatty degeneration in the liver, cell death in the kidneys and hemorrhages in the spleen.

Leptospira hemolysin destroys the walls of red blood cells, which leads to hemolysis, which releases a large amount of hemoglobin. This can be seen when taking blood tests. People experience pale skin, and blood pressure can drop significantly. Patients become very weak, quickly get tired, feel dizzy, and feel short of breath.

Due to the secretion of plasmacoagulase, leptospires are able to liquefy the blood due to the processes of coagulation and protein folding. This has the most detrimental effect on patients, since the resulting clots interfere with the full flow of blood: blood clots begin to form, which clog the walls of blood vessels. Patients with leptospirosis develop ischemia, which disrupts blood circulation in all internal organs. In turn, this can provoke a stroke, heart attack and various other acute conditions of the body that can lead to death.

The rash of leptospirosis spreads to the entire body. It appears approximately 3–5 days after the onset of the disease and occurs in more than half of all patients. The torso is affected first, and after a while - the limbs. The rash can be of different types: sometimes small reddish spots of a few millimeters are formed, and in some cases large bruises form, which then merge into one plaque. Herpetic rashes rarely appear in the area of ​​the upper lip and nostrils.

The organs of the urinary system are also often affected. The kidneys are primarily affected, and patients develop oliguria: less than 300–500 ml of urine is excreted per day.

Oliguria is a decrease in the amount of urine excreted by the kidneys.

In severe cases of the disease, the patient may develop anuria, in which the daily volume of urine is less than 100 ml, which is a critical value. In the shortest possible time, acute renal failure develops, swelling increases, and urine tests reveal an increased content of proteins and red blood cells.

When the heart is damaged, the patient's blood pressure drops sharply and arrhythmia develops. When conducting an electrocardiogram, doctors often detect signs of cardiac muscle dystrophy, rhythm and conduction disturbances. People complain of shortness of breath and fatigue.

Signs of the icteric form: hemorrhagic syndrome, liver failure and others

As the name suggests, this type of leptospirosis develops jaundice. It appears due to serious liver damage due to necrosis of hepatocytes, which is accompanied by the release of bile. The level of bilirubin in the blood increases, which affects the color of the skin and mucous membranes. Their color can vary from light yellow to dark orange. Jaundice is detected already in the first week of the disease and the patient’s condition deteriorates sharply. In this case, hemorrhagic syndrome often occurs, in which bruises form on the skin.

From 10 to 15 days, liver pain begins to intensify; it greatly increases in size due to fatty degeneration and stretching of the liver capsule. Due to hemolysis, bilirubin precursors - heme molecules - are released into the bloodstream, which also affect the color of the patient's skin. Liver failure often develops.

Clinical picture in the anicteric form

This form of leptospirosis does not cause liver damage. The disease occurs without the release of bile and an increase in the level of bilirubin in the patient’s blood. Do not think that the person will not face any complications. Patients also suffer from impaired integrity of blood vessels and other internal organs.

What is jaundice - video

Incubation period and stages of the disease

The incubation period ranges from 2 to 20 days. Doctors distinguish several stages through which people with leptospirosis go.

1. The first is a febrile period, during which the temperature begins to rise, headaches and muscle aches appear. Patients feel very nauseous and feel chills. This stage lasts approximately four days.
2. During the peak period, major damage to internal organs occurs. Cells of the liver, kidneys, heart and even brain begin to break down. It is at this stage that the largest number of deaths are recorded.
3. The recovery period is characterized by restoration of the functioning of internal organs. Respiratory and excretory functions are gradually normalized.

Diagnostics and differential diagnosis: blood tests, PCR and other studies

At the first signs of leptospirosis, you should contact an infectious disease specialist. First of all, the patient is examined and interviewed - the doctor collects an anamnesis. The condition of the skin and mucous membranes must be studied. Based on the data obtained, a conclusion is made about what diagnostic measures need to be carried out.

1. A complete blood count will not indicate the presence of leptospirosis. However, it can be used to establish that there is an infectious pathogen in the body. Patients exhibit increased white blood cell counts and erythrocyte sedimentation rates.
2. A biochemical blood test is also unable to detect the presence of bacteria. It is necessary to assess the condition of internal organs. An increase in the level of hepatic transaminases ALAT and AST is often diagnosed. These are characteristic signs of liver damage. In the icteric form, the level of bilirubin is significantly elevated.
3. The microscopic method is the most informative; it allows you to detect a harmful microorganism. The test uses the patient's blood, urine, or cerebrospinal fluid. Leptospira can be detected already in the first days of the disease. The downside of this study is the frequent false negative results.
4. Serological diagnosis is the main method of examination for leptospirosis. It consists of detecting special antibodies that are characteristic of this particular disease.
5. PCR (polymerase chain reaction) is a very accurate and modern way to diagnose various infectious diseases. Its accuracy reaches 99%.

Video about laboratory and instrumental diagnostics of leptospirosis

Treatment of an infectious disease

Therapy for leptospirosis must begin at the earliest stages of the disease. In no case should you self-medicate, since recovery without the necessary medications is almost impossible and there is a high risk of death. Medicines prescribed to patients are divided according to their intended purpose.

Much attention is paid to detoxifying the body, since the main complications occur precisely due to poisoning by toxins.

1. Hemodesis is necessary to restore plasma volume and normalize acid-base and water-electrolyte balances.
2. Enterodesis, due to a special substance - povidone, attaches toxins to itself and removes them from the body.
3. Mannitol is necessary for kidney problems. It has a diuretic effect, accelerating the elimination of harmful substances. Plasma osmotic pressure increases and blood volume in the body normalizes.
4. A solution of glucose with furosemide also helps to increase urine output.
5. Polysorb, Enterosgel and other similar drugs absorb harmful substances and bacteria from the gastrointestinal tract and remove them from the body along with feces. Most often used for icteric form.

The correct selection of antibiotics that are necessary to destroy the infectious agent of leptospirosis is very important. As a rule, drugs of the penicillin group are prescribed if there is no allergy to them.

1. Penicillin destroys the cell wall of Leptospira, which leads to their destruction.
2. Erythromycin prevents bacteria from producing proteins necessary for normal functioning.
3. Doxycycline also interferes with protein synthesis processes, stopping the reproduction and growth of Leptospira.

Patients may be prescribed plasmaphoresis, in which blood is removed from the patient’s bloodstream, purified using special devices, and reintroduced. In this case, the plasma is removed and replaced with special physiological solutions. This allows you to cleanse the body of toxins and significantly improve a person’s well-being. Also, a specialist may make a choice in favor of carrying out similar procedures - hemodialysis, hemosorption, hemofiltration and some others.

In acute and severe forms of the disease, special serums and globulins are prescribed. This improves a person’s immunity and speeds up recovery. All patients are prescribed bed rest.

Drugs prescribed for the treatment of patients with leptospirosis, pictured

Hemodesis helps normalize acid-base and water-electrolyte balances Enterodesis removes toxins from the body
Mannitol has a diuretic effect
Glucose solution accelerates the elimination of harmful substances Polysorb is often used for icteric forms Erythromycin is an antibiotic of the penicillin group Doxycycline interferes with the protein synthesis processes necessary for the normal functioning of bacteria

Prognosis of therapy and possible complications

Currently, the mortality rate from leptospirosis infection is very high and in some countries during epidemic periods reaches 35%. Patients often die from kidney or liver failure, which develops due to poisoning with toxic waste products of Leptospira.

Some patients develop meningitis due to pathogens crossing the blood-brain barrier. Terrible headaches and constant vomiting greatly exhaust patients. This complication is diagnosed in approximately 20% of all infected people. Consciousness can become confused, and people often fall into a coma.

In addition, a secondary infection may occur, which leads to:

• pneumonia;
• abscesses;
• bedsores.

Vaccination and other preventive measures

Some groups of people who work with animals or live in contaminated areas may be prescribed an anti-leptospirosis vaccine. It contains a large number of antibodies, which forms passive immunity in humans. The downside of this serum is its short-term effect; it is effective for no more than six weeks, after which a re-vaccination is required.

There is a very exotic method of preventing leptospirosis in Thailand. Local residents believe that eating rat meat helps reduce the risk of Leptospira infection. Currently, this method is unproven and dangerous.

It is necessary to follow various preventive measures that can significantly reduce the risk of contracting leptospirosis. You should adhere to the following tips:

• vaccinate all pets;
• destroy rodents, disinfect premises;
• exercise caution at work;
• do not drink water from unverified sources;
• wash vegetables and fruits;
• subject meat products to thorough heat treatment;
• wear rubber shoes when fishing;
• Avoid contact with stray animals and street rodents.

It is very important to explain to children the danger stray animals pose, which sometimes they so want to touch. It is also necessary to tell them about the possibility of infection when swimming and explain why under no circumstances should they drink water from street reservoirs.

The main burden in the prevention of leptospirosis falls on specialized government agencies, in particular sanitary and epidemiological services. They are responsible for timely vaccination of livestock and people at risk. It is important to bury animals in accordance with established rules so as not to provoke outbreaks of epidemics and the spread of infection.

Leptospirosis: source of infection, development factors and treatment - video

Leptospirosis is a very dangerous infectious disease that requires timely consultation with a doctor and compliance with all specialist recommendations. Under no circumstances should you self-medicate. Be careful and take precautions to reduce the risk of infection. Pay special attention to children: often they are not even aware of the dangers that stray animals and open bodies of water pose.

Leptospirosis is an infectious disease caused by Leptospira interrogatis, characterized by damage to the blood capillaries, liver, kidneys, muscles, central nervous system, often accompanied by jaundice. The causative agent of leptospirosis was isolated in 1914 by R. Inado and I. Ido.

Taxonomy. The causative agent of leptospirosis belongs to the department Gracilicutes, family Leptospiraceae, genus Leptospira.

Morphology and tinctorial properties. Leptospira are bacteria with a convoluted shape, 7-14 microns long, 0.1 microns thick; characterized by the presence of numerous small curls, the ends of the leptospira are bent in the form of hooks. Do not form spores or capsules; mobile - perform translational, rotational, flexion movements. Leptospira stains poorly with aniline dyes; according to Romanovsky-Giemsa, they stain pink and are gram-negative. The optimal way to study their morphology is dark-field microscopy.

Cultivation. Leptospira is cultivated under aerobic conditions on special nutrient media with native rabbit serum at 25-35ºC and pH 7.2-7.4. They grow slowly.

Enzyme activity. The biochemical activity of Leptospira is low.

Antigenic structure. Among the representatives of the genus Leptospira, there are about 200 serovars, grouped into 19 serological groups. The polysaccharide fibrillar antigen is genus-specific; membership in the group and variant is determined by envelope protein and lipoprotein antigens, respectively.

Pathogenicity factors. The pathogenic properties of Leptospira are due to the formation of little-studied exotoxin-like substances and endotoxins. Leptospira also produces fibrinolysin and plasmacoagulase.

Resistance. Leptospira die very quickly when exposed to high temperatures and disinfectants, but are quite resistant to low temperatures. In the water of natural reservoirs they remain viable for 5-10 days, in damp soil - up to 270 days.

Animal susceptibility. Many animals are sensitive to Leptospira.

Epidemiology. Leptospirosis is a widespread zoonosis and occurs in all parts of the world. There are natural foci of leptospirosis - mainly in forests, wetlands, and rivers. The source of infection in them are wild animals - rodents, foxes, arctic foxes, etc. The urine of animals gets into the water, polluting the soil and vegetation. The incidence is characterized by strict seasonality (June - September) and is associated with agricultural work (mowing meadows, hay harvesting), as well as picking mushrooms, berries, hunting, and fishing. In rural areas, the source of infection can be domestic animals: pigs, cattle, dogs. Infection can occur through food, for example by drinking milk. Contact-household transmission is also possible - when caring for sick animals. However, the main route of transmission of infection is water. Often in rural areas, when people bathe in bodies of water contaminated with the urine of sick animals, “swimming” outbreaks occur. Cases of leptospirosis are also possible in port cities where there are many rats.

Pathogenesis. The entrance gates of infection are the mucous membranes of the mouth, eyes, nose, and skin. Leptospira spreads through the lymphatic ducts, penetrates the blood and is carried throughout the body by the blood flow, reaching various organs - liver, kidneys, lungs, etc. In organs, microorganisms multiply intensively, then enter the blood again. As a result of the action of pathogens and their toxins, the wall of blood capillaries is damaged and hemorrhages are observed in various organs and tissues. The liver, kidneys, adrenal glands, heart, and muscles suffer the most.

Clinical picture. The incubation period usually lasts 7-10 days, the disease - 5-6 weeks. The disease, as a rule, begins acutely, body temperature rises to 39-40ºС, headache and sharp pain in the muscles, especially in the calf, appear. Depending on the damage to certain organs, symptoms of their damage appear: kidney failure, jaundice, etc. Wavy fever is characteristic. Clinical forms of leptospirosis vary - from mild to severe, leading to death.

Immunity. Immunity is long-lasting, intense, but characterized by strict serovar specificity.

Microbiological diagnostics. Blood is taken as material for research in the 1st week of the disease; later, urine and cerebrospinal fluid can be used. The bacterioscopic method (“dark-field microscopy”) is used: bacteriological, biological methods. But the most widely used serological method (RSK, RNGA, RA, lysis reaction); The presence of the disease is determined by the increase in antibody titer.

Treatment. Antibiotics and anti-leptospirosis heterologous immunoglobulin are used.

Prevention. Nonspecific prevention consists of following a number of rules: you should not use raw water from stagnant reservoirs for drinking and washing, or swim in small reservoirs, especially in livestock watering areas. For specific prevention for epidemic indications, a killed vaccine is used.

Leptospirosis is an acute natural focal zoonotic infectious disease caused by Leptospira. Leptospirosis in humans occurs with severe intoxication, febrile syndrome, the development of hemorrhagic disorders, acute renal failure (acute renal failure), damage to liver tissue and the central nervous system.
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Kidney damage, as well as the development of jaundice and intoxication syndrome, are mandatory for leptospirosis. The first mention of a disease that occurs with similar symptoms belongs to the Russian doctor Seydlitz (1841). In 1886, a student of S.P. Botkin, N.P. Vasiliev, became interested in this disease. He described seventeen cases of this disease and called it “infectious jaundice.” In the same year, research by Professor Weil appeared, describing similar clinical symptoms in four patients.

Thanks to these studies, the disease was identified as a separate nosological unit called Vasiliev-Weil disease.

The causative agent of leptospirosis was isolated in 1915 by several groups of scientists. They studied various serotypes of the pathogen, so each scientist gave the pathogen its own name. What was common to all isolated serotypes was the presence of a convoluted shape, so they were classified as spirochetes. In 1917, they were united under the common name Leptospira (delicate (thin) spirochetes).

In the sixties of the twentieth century, there were more than one hundred and twenty types of Leptospira that could cause diseases in humans. For some time they were divided into various infectious diseases: Vasiliev-Weil icterohemorrhagic leptospirosis, benign anicteric water fever, etc.

Further studies of the pathogen led to the conclusion that the pathogenetic mechanisms, and, consequently, the symptoms of leptospirosis in humans are similar, regardless of which serotype caused the disease. In this regard, since 1973, leptospirosis began to be considered as one nosological unit.

Previously, various forms of leptospirosis were called Vasiliev-Weil disease, water fever, swamp fever, meadow fever, dog fever, 7-day fever, Nanukai, swineherd's disease, etc.

ICD 10 code A27. Icteric-hemorrhagic forms of leptospirosis are classified with code A27.0. Unspecified forms are designated A27.9, and other forms are designated A27.8.

All Leptospira are extremely sensitive to high temperatures. They die instantly when boiled, but can remain highly pathogenic for several months when frozen.

The pathogen is also destroyed by bile, gastric juice and acidic human urine. Slightly alkaline urine of animals can retain the pathogen for several days.

When released into open water bodies, leptospirosis pathogens remain pathogenic and viable for a month. If exposed to damp, wet soil (swamps) – more than nine months. Leptospira can survive in food for several days. Drying and ultraviolet irradiation destroy Leptospira within a few hours.

The pathogen also quickly dies when boiling, salting and pickling foods. Its high sensitivity to disinfectants, penicillin, chloramphenicol and tetracycline is also noted.

How can you get leptospirosis?

Leptospirosis is one of the most common natural focal diseases. The source of infection is only animals. From an epidemic point of view, a sick person is considered a “dead end” of infection and does not pose a danger to others.

The main carriers and sources of infection are rats, voles, hamsters, hedgehogs, shrews, dogs, pigs, sheep and cattle. Leptospirosis is rare in fur-bearing animals (foxes, arctic foxes, nutria).

Path of infection with leptospirosis

Rodents suffer from leptospirosis asymptomatically, actively excreting the pathogen in the urine. Farm animals can be acutely ill, but also suffer the infection asymptomatically.

There is a pronounced summer-autumn seasonality of the disease. Susceptibility to leptospirosis is high. Men get sick more often than women.

After recovery, persistent immunity remains, but it is strictly serovar-specific, that is, it works against the type of Leptospira that caused the disease.

The incubation period for leptospirosis in humans ranges from two to thirty days (on average, the first signs of leptospirosis appear after one to two weeks).

Transmission of leptospirosis to humans is carried out mainly by water, less often by contact or food. Infection occurs during swimming in bodies of water contaminated with leptospira, drinking contaminated water, eating unwashed foods, and contacting sick animals. The maximum incidence of the disease is observed in miners (contact with damp soil) and agricultural workers. Recently, there has been a significant increase in the incidence of the disease in large cities (Moscow).

Due to the high mobility of the pathogen, it can enter the human body through the mucous membranes of the oral cavity, nasopharynx, esophagus, conjunctiva of the eyes, etc. In addition to the food transmission mechanism, it is possible to ingest or get water into the eyes while swimming. It is also possible for Leptospira to penetrate through open wounds, scratches, etc.

Inflammation at the site of primary penetration of Leptospira does not develop. Distribution throughout the body occurs hematogenously (through the bloodstream). The first phase of leptospirosis, during which the pathogen penetrates the tissues of the liver, spleen, kidneys, lungs, central nervous system, etc. corresponds to the incubation period.

Classification of leptospirosis

According to the type of clinical course, icteric and anicteric forms are distinguished.

In connection with the leading syndrome, leptospirosis can be renal, hepatorenal, meningeal or hemorrhagic.

The severity of the disease can be:

• mild (accompanied only by fever and does not lead to damage to internal organs);
• moderate (severe fever and moderate damage to internal organs);
• severe (the disease is accompanied by the development of jaundice, thrombohemorrhagic syndrome, meningitis, acute renal failure).

Also, the infection can proceed uncomplicated, or lead to the development of ITS (infectious-toxic shock), acute hepato-renal failure, acute kidney damage, etc.

Leptospirosis in humans - symptoms and treatment

The onset of the disease is always acute. The first signs of leptospirosis are a rise in body temperature to forty degrees, a wave-like course of fever, chills, soreness in muscles and joints, severe lower back pain, headaches, nausea and vomiting, and lack of appetite.

Maximum pain is observed in the lumbar region, as well as the calf muscles. The neck, back and abdominal muscles are less painful. There is a sharp increase in pain when moving (patients' independent movement is limited) and palpating the muscles.

Feverish syndrome and severe intoxication are associated with the accumulation of decay and metabolic products of the pathogen in the blood. The maximum concentration of the pathogen in the phase of secondary bacteremia is observed in the liver. At the same stage, symptoms of capillary damage and active hemolysis of red blood cells may develop due to the production of hemolysin by the pathogen.

The destruction of red blood cells leads to massive release of bilirubin and the development of icteric syndrome. The severity of jaundice increases due to damage to the hepatic capillaries, the development of edema and serous hemorrhages. Inflammation in the liver tissue contributes to a pronounced disruption of the bile-forming and excretory functions of the liver.

Clinically, damage to the liver and red blood cells is manifested by yellowness of the skin, gingival and nasal bleeding, hemoptysis (in severe cases, bleeding from the gastrointestinal tract and uterine bleeding develops).

When the kidneys are damaged, the clinical picture of acute renal failure (lack of urination) develops. In severe cases, death from uremia is possible. The development of uremia is accompanied by vomiting, diarrhea, the appearance of “uremic frost” on the skin and hair, hypothermia, respiratory and heart failure, lethargy, loss of consciousness (coma is possible), and the appearance of an ammonia odor from the mouth.

When the central nervous system is affected by leptospira and their toxins, purulent (less often serous) meningitis or meningoencephalitis develops.

Severe intoxication symptoms and damage to capillary walls contribute to active microthrombosis and the development of disseminated intravascular coagulation (DIC syndrome).

Also, leptospirosis pneumonia, iritis, iridocyclitis, and myositis often develop. In rare cases, leptospirosis myocarditis may occur.

In the abortive (erased) form, the symptoms of leptospirosis are limited to febrile and intoxication syndromes, without signs of damage to organs and systems.

Diagnosis of leptospirosis in humans

On examination, the patient's appearance is striking:

• jaundiced skin;
• yellowness of the sclera (hemorrhages into the conjunctiva are possible);
• puffiness and redness of the face, neck and upper half of the body;
• enlarged lymph nodes (submandibular, cervical);
• polymorphic measles-like or rubella-like (extremely scarlet-like) rash located on the limbs and torso;
• herpetic rash on the nose and lips;
• hemorrhages in the soft palate, hyperemia of the tonsils and posterior pharyngeal wall.

A highly specific symptom is complaints of pain in the lower back and calf muscles, as well as the development of thrombohemorrhagic syndromes (bleeding from the nose, gums, hemorrhages after injections).

Palpation reveals an enlarged, painful liver and spleen, as well as sharp pain in the calf muscles.

Bradyarrhythmia, arterial hypotension, muffled heart sounds, and the appearance of various noises are noted. There may be signs of diffuse damage to the heart muscle on the electrocardiogram.

When pneumonia develops, patients complain of chest pain, shortness of breath, and cough. There is a dullness of pulmonary sound upon percussion.

The development of inflammation of the meninges is accompanied by the appearance of meningeal signs and specific changes in the CSF (cerebrospinal fluid).

Urine tests show proteinuria, cylindruria, hematuria, and renal epithelium may be detected. There is a decrease or absence of diuresis.

In the blood, bilirubin, ALT and AST, potassium, urea and creatinine are increased. A general blood test is characterized by a high ESR, the development of neutrophilic leukocytosis, aneosinophilia, thrombocytopenia, and anemia.

Differential diagnosis of leptospirosis and hepatitis

Specific diagnostics are provided bacterioscopically, bacteriologically, biologically and serologically.

In the first few days of the disease, it is possible to detect the pathogen during dark-field microscopy of blood, and later - urine and cerebrospinal fluid.

Diagnosis using culture is more reliable, but Leptospira grows extremely slowly, so this method is not suitable for rapid diagnosis.

Serological testing is considered the gold standard for diagnosing leptospirosis. For this purpose, PMA (microagglutination reaction) is performed, since it is characterized by maximum specificity and high sensitivity. In addition to confirming the diagnosis, this method allows you to clarify the serogroup of the pathogen.

A serological test for leptospirosis in humans is informative from the seventh (rarely from the fourth) day of illness, with the appearance of antibodies to the pathogen in the patient’s blood.

Also, enzyme immunoassay (ELISA) or PCR is highly informative. PCR analysis is informative even against the background of antibacterial therapy and can be used from the first day of the disease.

Algorithm for diagnosing leptospirosis

Treatment of leptospirosis

Leptospirosis has an unpredictable course and a high risk of developing severe and fatal complications, so hospitalization of patients is mandatory. The disease cannot be treated at home.

Treatment of leptospirosis is always complex and includes:

• prescribing a gentle dietary diet (No. 7 diet for damage to renal tissue and No. 5 for damage to the liver parenchyma);
• strict bed rest;
• carrying out detoxification;
• dehydration therapy;
• hormonal therapy;
• correction of electrolyte balance and elimination of MA (metabolic acidosis);
• administration of fresh frozen plasma, albumin, platelet mass;
• prevention and treatment of consumption coagulopathy;
• prescribing non-steroidal anti-inflammatory drugs to eliminate febrile syndrome;
• prescription of antimicrobial agents (etiotropic treatment).

Antibacterial therapy for leptospirosis

The drugs of choice for the treatment of leptopyrosis are penicillin. The first-line antibiotic is benzylpenicillin sodium salt. Reserve drugs (alternative drugs) are doxycycline ®, ciprofloxacin,.

Vaccination against leptospirosis is carried out according to epidemic indications, as well as agricultural workers, people working with dogs (dog handlers), employees of zoos, pet stores and miners (as indicated).

The leptospirosis vaccine is administered subcutaneously (once) in a dose of 0.5 milliliters. After a year, revaccination is indicated. Vaccination against leptospirosis can be given to persons over seven years of age.

Epidemiology of the disease

The infection occurs on all continents, with the exception of Antarctica. Leptospirosis is especially widespread in countries with tropical humid climates. The carriers of the disease are wood mice, water rats, dogs, cattle, pigs, rats and some other animals. In people diagnosed with leptospirosis, symptoms appear after consuming meat and milk from infected animals, cutting meat, or prolonged contact with water contaminated with the excretions of carriers. The specificity of the pathogen entering the body determines the risk groups. The most frequently affected people are livestock farm workers, shepherds, milkmaids, veterinarians and people working in wet meadows. Typically, leptospirosis is diagnosed in people during the summer months, especially August, when conditions are ideal for the bacteria to multiply.

Leptospirosis - symptoms of the disease

The incubation period of infection lasts from 2 weeks to 1 month. The disease begins with acute symptoms:

• severe chills;
• a sharp increase in body temperature to 39-40 degrees;
• headaches;
• pronounced muscle pain (the calf muscles hurt very much);
• changes in the skin of the face - it becomes hyperemic, puffy. Patients experience dilation of blood vessels and conjunctival hyperemia, which often lead to hemorrhages.

In the first week after the onset of the disease, exanthems of various types may appear. In severe forms of the disease, hemorrhagic rashes are observed, localized on the elbows and in the armpits. In addition, when leptospirosis is diagnosed, treatment includes correction of the liver, kidneys and cardiovascular system, since patients develop urinary retention, Pasternatsky's symptom, rapid breathing, decreased blood pressure and tachycardia.

Signs of fever are observed for about a week, after which the temperature returns to normal. After 3-4 days, a new increase in temperature is possible, but this time it subsides after 1-2 days. In some cases, lectospirosis in humans leads to the development of icterus, which is accompanied by a significant enlargement of the liver and a change in the color of urine.

If left untreated, the disease causes serious complications - acute liver or kidney failure, meningitis, iritis, iridocyclitis and encephalitis. Depending on the state of a person’s immune system, other serious consequences may occur.

Diagnosis of the disease

To determine the presence of Leptospira, blood samples are examined using direct microscopy. In addition, the pathogen is isolated when blood is cultured on nutrient media. The diagnosis can also be confirmed serologically using the RIGA, RSK, microagglutination-lysis reactions.

Leptospirosis - treatment of the disease

All patients are subject to mandatory hospitalization. Etiotropic therapy consists of taking penicillin. The standard dosage of the drug is 6,000,000-12,000,000 units/day. The main treatment for leptospirosis is doxycycline. Doctors also use gammaglobulin. Since there is a danger of developing renal pathologies, osmo- and saluretics are recommended for patients. Hemodialysis is prescribed when symptoms of acute renal failure occur.

For prevention purposes, it is necessary to regularly vaccinate personnel of livestock farms and enterprises involved in processing meat and dairy products.

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