Can there be asymptomatic leptospirosis? Leptospirosis

Leptospirosis is a group of infections that occur in the human body in the form of a febrile disease. The causative agent of leptospirosis is Leptospira, a microorganism from the family of spirochetes.

For the first time, leptospirosis as an independent disease was described in detail by the German scientist Weil back in 1886. Among Russian scientists, N.P. Vasiliev worked on the study of leptospirosis, and in 1888 he described this disease under the name “infectious jaundice.” Since then, many studies have been conducted to study the causes of the disease, but even now doctors cannot avoid mortality in severe forms of the disease.

What it is?

Leptospirosis is an infectious disease caused by special bacteria called Leptospira. Most often, the disease can be acquired by swimming in a small body of water contaminated with leptospira or by eating raw water, meat or milk from animals with leptospirosis.

There are several types of this disease, some of which can be very life-threatening.

Etiology and pathogenesis

They penetrate the host’s body through the skin and mucous membranes, and then settle in the lymph nodes and begin to actively multiply. Leptospirosis then spreads to other organs and systems, accumulating mainly in the kidneys, liver and central nervous system. The activity of harmful microorganisms leads to necrotic and degenerative changes in tissues, disruption of the integrity of the epithelium of the renal tubules, the development of disseminated intravascular coagulation syndrome and subsequent hemorrhagic rashes.

Routes of infection:

1. Contact - if a person had direct contact with a sick animal or touched contaminated household items or water.
2. Nutritional – when eating products from infected animals and infected plant waste products.
3. Aerogenic - if contaminated air enters the respiratory tract.
4. Transmissible - as a result of flea bites or infected ticks.

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.

Symptoms

In humans, the latent period for leptospirosis lasts from four days to two weeks. The disease begins suddenly, acutely, without warning and is characterized by:

• severe headache;
• insomnia;
• severe pain in the calf and other muscles;
• myalgia accompanied by skin hyperesthesia;
• puffiness and hyperemia of the neck and face;
• chills;
• injection of scleral capillaries;
• increase in temperature;
• constant thirst;
• loss of appetite.

On the fourth day after the first manifestation of signs of the disease, the symptoms are supplemented by icteric staining of the skin, the appearance of exanthema, hypotension, bradycardia, muffled heart sounds, as well as pathological changes in the epithelium of the respiratory tract. During the same period, in almost all patients the liver and spleen noticeably increase in volume, and symptoms of kidney tissue damage appear.

In severe cases of leptospirosis, toxicosis increases in patients, associated manifestations appear, and symptoms of uremia appear.

Diagnostics

Conducting laboratory tests allows the doctor to determine leptospirosis even with erased forms of the disease. The approximate set of necessary studies looks like this:

1. General urine analysis (hematuria, casts, bile pigments are determined);
2. Clinical blood test (neutrophilic leukocytosis, accelerated ESR, anemia, decreased platelet count are determined);
3. Biochemical blood test (increase in bilirubin, as well as enzymes ALT, AST, alkaline phosphatase, CPK, decrease in prothrombin level, increase in blood clotting time);
4. Analysis of cerebrospinal fluid (neutrophilic or mixed pleocytosis, increased protein content, red blood cells are determined);
5. Serological methods ELISA, RA, RNGA (allow you to determine specific antibodies to Leptospira with a subsequent increase in their titers);
6. Bacterioscopy (detection of leptospira in blood, cerebrospinal fluid, urine);
7. PCR (allows you to detect Leptospira DNA in the patient’s biological materials).

Complications of the disease

Dangerous complications of the disease can be:

• renal failure;
• bleeding;
• eye lesions;
• hepatic coma;
• infectious-toxic shock;
• meningitis;
• secondary pneumonia,
• visual impairment;
• heart disorders;
• paralysis, paresis;
• abscess,
• bedsores.

High mortality is recorded due to renal or hepatic disorders, and is about 60%.

Treatment of leptospirosis

Treatment of patients should be carried out in a hospital setting. Patients with severe forms of the disease are placed in intensive care units for constant monitoring of their health status and the dynamics of laboratory parameters.

The main directions in the treatment of leptospirosis in humans are direct control of the pathogen and individual pathogenetic therapy (which implies treatment of the affected organs, taking into account the mechanism of development of the disease).

Among the huge number of modern antibiotics for leptospirosis, preference is given to the banal group of penicillin. As it turned out, the penicillin series is most destructive for Leptospira. Penicillin is prescribed in a dose of 4 to 12 million units per day, divided into several doses. The total duration of antibiotic therapy is 10-14 days. It is more favorable for recovery if such therapy is started in the first four days from the onset of the disease, otherwise the effectiveness of treatment is lower.

Pathogenetic therapy is aimed at reducing symptoms of intoxication, replenishing fluid losses by the body, and correcting blood system parameters and homeostasis. It mainly involves the use of:

• enterosorbents (Enterosgel, Polysorb, Polyphepan and others);
• antihistamines (anti-allergic) drugs (Suprastin, Loratadine, Zodak, Suprastinex and others);
• analgesics and non-steroidal anti-inflammatory drugs (Ibuprofen, Paracetamol, Xefocam and others);
• infusion solutions and detoxification drugs (saline sodium chloride solution, glucose solutions, potassium preparations, Ringer's solution, Reosorbilact, Reamberin and so on);
• hormones (they are especially indicated in severe cases, with increased bleeding and severe intoxication). Prescribed in a short course with a gradual dose reduction (Prednisolone, Dexamethasone);
• antioxidants and antihypoxants (vitamin E, C, Mexidol, Mildronate, Cytoflavin, Essentiale, Glutargin, Actovegin, Cerebrolysin, Octolipen and others). The choice of a specific drug is determined by the damage to a particular organ. For example, in case of liver damage, Essentiale is preferable, and in case of damage to brain tissue, Cerebrolysin is preferable.

In severe cases, medication alone is not enough. Renal and liver failure may require extracorporeal detoxification methods (hemodialysis, plasmapheresis, hemosorption, hemofiltration). The number of procedures will be determined by homeostasis indicators, urine and blood tests, and the general condition of the patient.

Rehabilitation period

After successful treatment of leptospirosis, patients should be registered with a dispensary for a period of about six months. During this period, rehabilitation measures are carried out, consisting of consultations with an ophthalmologist, neurologist, therapist or pediatrician (if the patient is a child). After six months, the patient must appear every month for an appointment with a therapist, who, if necessary, will prescribe an examination with a specialized specialist. During the first two months of rehabilitation, clinical and laboratory examinations are carried out regularly.

If at the end of the rehabilitation period the test for leptospirosis does not give positive results, the patient is removed from the register. Otherwise, observation with appropriate rehabilitation measures lasts for 2 years.

Prevention

Leptospirosis is a dangerous disease with high mortality, but specific preventive measures have not yet been developed. This is due to the fact that different strains of Leptospira differ in antigenic components. Therefore, it is not possible to create a vaccine that would reliably protect against infection.

You can prevent the disease in this way:

1. Eliminate or limit as much as possible swimming in stagnant bodies of water in natural conditions;
2. Fight against small rodents. It must be carried out in residential buildings and, especially, in public catering facilities, food warehouses and stores. Each representative of this series of animals can be a carrier of leptospirosis infection;
3. Emergency antibiotic prophylaxis with doxycycline after possible infection or the appearance of any manifestations of prodromal symptoms;
4. Use of protective rubberized suits if contact with infected water is necessary.

After suspected infection, doxycycline may be prescribed as emergency prophylaxis.

Leptospirosis is a zoonotic infectious disease caused by bacteria of the genus Leptospira. These microorganisms are found everywhere except Antarctica. Most common in countries with tropical climates. Leptospires are stable in the environment. Thus, bacteria can exist in reservoirs for about thirty days, and in moist soil for up to nine months.

Table of contents:

Causes

The source of infection is primarily rodents, hedgehogs, as well as farm animals (pigs, cattle), dogs. Leptospira are excreted in animal waste products, polluting water, soil, vegetables, and plants. It is impossible to become infected with leptospirosis from a sick person.

The disease has many transmission mechanisms:

1. Nutritional - infection occurs when drinking water from open reservoirs, as well as food contaminated with the urine of a sick animal;
2. Contact - infection occurs when damaged skin or mucous membranes come into contact with contaminated water or soil.

A person runs the risk of contracting leptospirosis when swimming in stagnant bodies of water. Water can be contaminated with urine and feces of sick animals. Thus, Listeria can penetrate not only through damaged skin, but also the mucous membrane of the mouth, nose, and also through the conjunctiva of the eyes. You can get leptospirosis even by walking barefoot on contaminated soil.

People working on livestock farms, meat processing plants, and those working in wetlands are at high risk of the disease. You should not discount veterinarians, animal shelter workers, and public utility workers who can become infected from sick dogs.

Human susceptibility to infection is very high. So, when swimming in a pond, a person can get sick even if there is a small area of ​​damaged skin and a small amount of bacteria in the water.

The incubation period ranges from three to thirty days, but on average it is six to fourteen days. The range of clinical manifestations is very wide. The disease can occur in icteric and anicteric forms, with a clear clinical picture or a blurred one. Leptospirosis is characterized by a polymorphism of clinical symptoms observed in other diseases. Therefore, the disease requires careful differential diagnosis. During the course of the disease, the following periods are distinguished:

1. Elementary;
2. Convalescence.

Initial period

The disease develops acutely, the temperature suddenly rises to 39-40 degrees, the person suffers from chills, weakness, nausea, vomiting, and pain in the lumbar region. Fever may last for a week and be persistent or recurrent. A pathognomonic sign of the disease is muscle pain, particularly in the calves. The pain intensifies with palpation of the muscles. Thus, the occurrence of pain during palpation of the anterior abdominal wall may be mistakenly perceived by the doctor as a symptom of an acute abdomen.

The person’s appearance is striking: the skin of the face and upper body becomes red, puffy (hood symptom), the sclera is injected. The tongue is dry, covered with a gray and later brown coating. Herpetic rashes may appear in the area of ​​the lips and wings of the nose.

On the third to sixth day of illness, a rash appears on the skin: dotted, roseolous, urticarial. This symptom is observed in approximately 30-40% of patients. Leptospira secretes endotoxin, which destroys red blood cells. This leads to hemorrhages in the sclera and conjunctiva, as well as nosebleeds. From a prognostic point of view, the earlier the patient developed hemorrhagic syndrome, the more severe the course of the disease should be expected.

There is an increase in the size of the liver and spleen. Signs of kidney damage may appear: lower back pain, decreased urination, urine becomes reddish.

Leptospires are able to penetrate the blood-brain barrier, reaching the brain. Approximately 20% of patients develop meningeal syndrome: the headache intensifies, is not eliminated by painkillers, vomiting and meningeal symptoms appear.

The duration of the initial period is seven days.

Approximately in the second week of illness, the temperature and intoxication begin to decrease. But the patient's condition does not improve. Jaundice, which appeared at the end of the initial period, becomes more and more pronounced. As jaundice increases, an enlargement of the liver and spleen is also observed. It is worth noting that anicteric forms of leptospirosis are not at all uncommon.

Groups of people at high risk of infection (veterinarians, livestock breeders, meat processing plant workers, disinfectants) must wear protective clothing when performing their work duties. In addition, these people are subject to vaccination with killed leptospirosis vaccine, which is administered subcutaneously in 2 ml doses twice, with an interval of ten days. After a year, revaccination should be carried out.

After suspected infection, doxycycline may be prescribed as emergency prophylaxis.

Grigorova Valeria, medical observer

Leptospirosis in humans- a natural focal bacterial zooanthroponotic disease, which is characterized by anemia, fever, hemorrhagic damage to the liver, kidneys, mucous membranes of the oral cavity, gastrointestinal tract, as well as central nervous system disorder.
Symptoms appear instantly, so treatment should be prescribed promptly.

Therapist: Azalia Solntseva ✓ Article checked by doctor

Symptoms and treatment of leptospirosis in humans

Leptospirosis is a widespread and potentially lethal zoonotic infection limited to many endemic foci in the tropics. Causes serious epidemics after heavy rains and floods.

Infection occurs through direct or indirect contact with infected animals, which carry pathogenic organisms in the renal tubules, releasing them in the urine.

Although wild and domestic animals can serve as reservoirs of infection, the gray rat (Rattus norvegicus) is the most common source of disease in humans.

Individuals living in urban slum areas characterized by poor sanitation and housing conditions are at risk of exposure to rats and leptospirosis.

The number of patients is expected to increase due to demographic shifts and subsequent growth of poor urban populations in tropical regions, as well as urban flooding due to climate change.

However, the population of such countries doubts that this can happen, so they do not make any special attempts to protect themselves.

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Symptoms and signs

• fever;
• headache;
• chills;
• muscle pain;
• vomit;
• yellowness of the skin and eyes;
• redness of the eyes;
• stomach ache;
• diarrhea;
• rash.

Many of these symptoms can be mistaken for other diseases. Sometimes some infected people may not show signs of the disease at all.

The time between a person's contact with a contaminated source and the onset of symptoms is 2 to 4 days.

The disease usually begins suddenly with an increase in temperature and proceeds in two stages:

1. After the first stage (with fever, chills, headaches, muscle pain, vomiting or diarrhea), the patient may recover briefly, but then falls ill again.
2. The second stage, if developed, is more severe. The person may develop kidney or liver failure, or meningitis.

The duration of the disease ranges from several days to 3 weeks or more. Without treatment, recovery can take up to three months.

Antimicrobials are prescribed for severe leptospirosis, while their use may be controversial for mild cases.

A Cochrane review found insufficient evidence to support the use or non-use of antibiotics.

Treatment in the early stages showed the best results.

Treatment during the immune phase has shown mixed results.

Mild forms can be treated with doxycycline, ampicillin and amoxicillin. For severe forms, penicillin G has long been used, although third-generation cephalosporins, cefotaxime and ceftriaxone, have also become widely used.

Alternatively, ampicillin, amoxicillin or erythromycin can be used. Some other antibiotics, such as macrolides, fluoroquinolones, and carbapenems, may be useful but are not recommended in clinical practice.

Severe forms of leptospirosis can damage internal organs and lead to multiple organ failure. Maintenance therapy and monitoring of complications from the genitourinary, hepatic, hematopoietic and central nervous systems are necessary.

Patients should be hospitalized until organ failure and clinical manifestations of infection have completely resolved. Follow-up should be aimed at assessing renal function. Cardiac evaluation may also be indicated by the patient with characteristic signs.

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Leptospirosis test

Laboratory tests used to examine the patient:

• enzyme-linked immunosorbent assay (ELISA) for the detection of IgM/IgG immunoglobulins to the pathogens of leptospirosis;
• polymerase chain reaction (PCR) of blood, urine and cerebrospinal fluid (CSF);

Laboratory tests used to confirm the diagnosis of leptospirosis in a patient:

1. The microagglutination test (MMA) is the diagnostic standard for determining Leptospira.
2. A titer value >1:200 or a 4X increase in serum between the first and fourth weeks of illness is considered a positive result.
3. PCR of DNA, blood, urine, CSF and tissues.
4. Culture of Leptospira from body fluids or tissues (also a diagnostic standard, but requires several weeks of incubation)

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Dangerous consequences and complications

Acute kidney damage is the most common complication of leptospirosis. Also an important cause of mortality in developing countries is pulmonary involvement followed by profuse bleeding (severe hemorrhagic pulmonary syndrome).

Liver dysfunction is usually not severe and is easily reversible. Various forms of thrombocytopenia are also diagnosed with leptospirosis.

The main consequences of leptospirosis in humans:

• spontaneous abortion in pregnant women;
• acute kidney injury;
• thrombocytopenia;
• liver failure;
• DIC syndrome;
• gastrointestinal bleeding;
• pulmonary hemorrhage;
• rhabdomyolysis;
• ocular disorders such as chronic or recurrent uveitis, iridocyclitis, chorioretinitis;
• adult respiratory distress syndrome;
• hypotension; vascular collapse can be sudden and fatal in the absence of prompt supportive treatment;
• acute cerebrovascular accident, subarachnoid hemorrhage, cerebral arteritis;
• Kawasaki disease;
• erythema nodosum;
• myocarditis;
• rarely heart failure, but with nonspecific changes on the ECG.

Microbiology of human disease

Leptospira shares common structural features that distinguish these spirochetes from other bacteria. The cell is surrounded by an outer membrane consisting of 3 to 5 layers.

Beneath the membrane is a flexible layer of peptidoglycan and a cytoplasmic membrane that protect intracellular contents. Collectively, the structures surrounded by the outer membrane are called the protoplasmic cylinder.

An unusual feature of spirochetes is the arrangement of flagella, which are located between the peptidoglycan layer and the outer membrane and are called periplasmic flagella.

The periplasmic flagella are attached to the protoplasmic cylinder subterminally at each end and extend toward the center of the cell.

Microbiology records that the number of periplasmic flagella varies among spirochetes. In viscous media, the mobility of bacteria with external flagella decreases, but in spirochetes, on the contrary, it increases.

Leptospires, too thin to be examined with a light microscope, can be easily observed with dark-field microscopy and are poorly stained with aniline dyes.

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The causative agent of a dangerous disease

Leptospira are very thin, twisted, obligate aerobes characterized by an unusual type of motility.

There are two species of Leptospira: pathogenic L. interrogans and free-living L. biflexa. The causative agent of leptospirosis is the serotype L. Interrogans. Unlike the pathogenic species, L. biflexa exists in water and soil as free-living organisms.

Although L. biflexa has occasionally been found in mammals, no pathology has been identified that is associated with this species, nor is it capable of infecting experimental animals.

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Vaccine against leptospirosis

There has long been an attempt to find an effective vaccine to prevent the development of leptospirosis, through immunization of people and animals at high risk.

Although several vaccines have been developed against leptospirosis, they remain ineffective for clinical use, despite decades of research and millions of dollars of investment.

Chemoprophylaxis (the use of drugs to prevent infection) is possible in certain circumstances.

For some individuals who are exposed to short-term risks of infection (for example, military personnel), doxycycline (200 mg per week) may be used one to two days before expected exposure.

This method provides 95% protection against infection. However, such preventative treatment is not recommended in the long term.

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Main forms of leptospirosis

Experts agree that leptospirosis manifests itself in two clinical syndromes: icteric and anicteric (the existence of a third asymptomatic syndrome is a matter of debate).

Anicteric - mild flu-like condition

Icteric leptospirosis, also known as Vasiliev-Weil disease, is a serious disease with multiple organ damage or complete disruption of their functions.

Most infections caused by leptospirosis are asymptomatic or have minor symptoms, and patients most often do not seek medical help.

Most cases develop with a sharp increase in temperature. Other symptoms include chills, headaches, muscle aches, bruising, abdominal pain and, much less commonly, a skin rash.

If a rash does occur, it often resolves quickly, in less than 24 hours. Anicteric syndrome lasts about a week and its resolution ends with the appearance of antibodies.

Jaundice is a severe subtype of pathology

Manifestations of severe infection develop 1-3 days after mild symptoms have passed. If the condition progresses to severe infection, internal organs may be affected, including the brain, liver, kidneys, heart and lungs.

This may lead to the development of the following symptoms:

• jaundice;
• swelling of the legs and arms;
• chest pain;
• symptoms of meningitis or encephalitis such as headache, vomiting and seizures;
• feeling of lack of air;
• coughing up blood.

Left untreated, the disease can become life-threatening and lead to brain damage, kidney failure, internal bleeding and impaired pulmonary function.

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Common transmission routes

Mucous membranes and skin lesions are the most common entry points for pathogenic Leptospira. A generalized infection develops, but there is no damage at the site of infection.

Bacteremia appears during the acute, leptospiremic phase of the disease. The host body responds by producing antibodies, which, in combination with a compliment, can have a bactericidal effect.

Leptospira are quickly released from all host tissues except the brain, eyes and kidneys. Organisms that survive in the brain or eyes develop very slowly.

However, in the kidneys they actively multiply in the convoluted tubules and are released in the urine stream. In the host, Leptospira can survive for weeks or months; in rodents they can be excreted in urine throughout the animal's life. Urine containing leptospira is not the only way of transmitting the virus.

Direct or indirect contact with urine containing virulent Leptospires is the main mechanism of transmission. As mentioned above, Leptospires enter through mucous membranes or minor breaks in the skin from water or soil contaminated with animal urine.

Most often, with leptospirosis, the rash becomes macular ( spotted) character. The element of such a rash is the macula - a spot that is flush with the skin, that is, does not protrude above its surface. The size of the spots ranges from 1 to 5 centimeters. These spots tend to merge. When they merge, they form large erythematous fields. With severe hemorrhagic syndrome, a petechial rash is observed. An element of such a rash is petechiae - small hemorrhage into the skin. Very often the rash is accompanied by herpetic eruptions on the wings of the nose and lips.

The development of rashes and hemorrhages in leptospirosis is explained by vascular damage. The pathogenicity factors of Leptospira are mainly directed at the network of blood vessels. Thus, Leptospira endotoxin has a direct destructive effect on the vascular epithelium. At the same time, factors such as hemolysin and fibrinolysin thin the blood. Thus, through defects in the vascular wall, bleeding occurs and small hemorrhages form. The larger the defects in the vessels, the larger the hemorrhages.

Conjunctival hemorrhages, nosebleeds
Hemorrhages in the conjunctiva, sclera and other mucous membranes appear on the 5th – 6th day of the disease. Their appearance is also associated with a violation of the integrity of blood vessels. Leptospira toxins primarily affect the small vessels of the eye, namely the conjunctiva. Nosebleeds are observed in more severe forms. They are associated not only with increased vascular permeability, but also with blood thinning.

Hemorrhages occur not only in the conjunctiva or sclera, but also in a number of internal organs. However, such hemorrhages are not visible and are manifested only by disruption of the functioning of these organs. Their presence is also confirmed by pathomorphological autopsy. Statistics from autopsies of patients who died from leptospirosis indicate that hemorrhages are most often observed in the kidneys, heart and liver.

Jaundice

Jaundice is a yellowish coloration of the skin and mucous membranes. The shade of yellow can be very varied - from bright yellow to dark brown. Jaundice discoloration of the skin is accompanied by enlargement and tenderness of the liver, as well as other symptoms associated with damage to the liver tissue.

Depending on the presence of this symptom, two forms of leptospirosis are distinguished - icteric and anicteric. In the icteric form, severe liver damage occurs. The development of jaundice is caused by both destructive processes in the liver tissue and increased destruction ( hemolysis) red blood cells. The development of a characteristic color is due to an increased concentration of bilirubin in the blood. Bilirubin is a bile pigment whose color depends on its shape. Normally, it is found in a certain amount in the blood. When its concentration increases, the tissues turn yellow. Increased bilirubin concentration is caused by damage to hepatocytes ( liver cells) and the release of bile from them. This symptom also develops due to increased breakdown of red blood cells. Red blood cells contain heme molecules ( iron complex), which are the precursor of bilirubin. Thus, when red blood cells are destroyed ( red blood cells) components of bilirubin come out of them, which also provoke a jaundiced coloration of the skin.

Typically, jaundice develops during the first week of illness and progresses very quickly. The skin color quickly turns yellow, sometimes acquiring a saffron tint. It is worth noting that the intensity of the color depends on the patient’s initial complexion. The lighter the patient's skin, the brighter the yellow color will be. Jaundice often develops with severe hemorrhagic syndrome. In this case, against the background of yellowish skin, initially small and then increasingly larger hemorrhages appear.

On days 10–15, liver pain increases and the patient experiences pain in the right hypochondrium. The pain is caused by an increase in liver volume ( due to fatty degeneration) and stretching of the liver capsule. The liver capsule is represented by a dense fibrous membrane, which is penetrated by many nerve endings. When jaundice develops, the liver enlarges and puts pressure on the capsule, causing pain.

Jaundice is accompanied by the development of not only objective symptoms, but also a number of laboratory signs. Thus, it is accompanied by an increase in the level of bilirubin, liver enzymes and other indicators.

Damage to internal organs

When Leptospires enter the human body, they are carried through the blood and lymph flow to all organs and systems.

Leptospirosis most often affects:

• kidneys;
• liver;
• heart;
• brain and its membranes.

Kidney damage very often develops at the height of the disease. This is primarily manifested by urinary retention and the development of oliguria ( decrease in daily urine volume less than 300 – 500 ml). Severe forms of leptospirosis are characterized by the development of anuria, in which the daily volume of urine is less than 100 ml. Renal failure increases rapidly, which is accompanied by edema, increased protein content in the urine and the presence of red blood cells in it. Renal failure is often accompanied by liver failure. So-called renal-liver failure is a common cause of death in patients with leptospirosis. The reason for this is the direct toxic effect of leptospira and their toxins on the epithelium of the renal tubules. As a result, all stages of the urine formation process are disrupted, and oliguria and anuria develop.

Damage to the cardiovascular system is manifested by a decrease in blood pressure, arrhythmic pulse and the development of blockades. The electrocardiogram shows signs of cardiac dystrophy, rhythm and conduction disturbances.

Damage to the brain and its membranes is manifested by the development of meningitis and meningoencephalitis. These symptoms occur in 20–30 percent of patients and are associated with the penetration of Leptospira through the blood-brain barrier. In this case, the patient suffers from a severe headache and uncontrollable vomiting. The consciousness of such patients is usually confused, and sometimes precomatose states develop. Leptospirosis meningitis can develop both at the beginning of the disease and at the end. In the latter case, it can cause death.

Clinically, there are three main periods during this disease. The initial period is preceded by a prodromal phase. This phase is not characterized by any symptoms. During the prodrome of leptospirosis, the pathogen enters the body and its primary dissemination occurs. This time takes from 3 to 30 days. After this, leptospira again enters the blood from the internal organs. From this moment the febrile period of the disease begins.

The following clinical periods of leptospirosis are distinguished:

• febrile period of the disease;
• peak period;
• recovery period.

The febrile period corresponds to general symptoms of intoxication - headache, aches, pain in the calf muscles, nausea, vomiting. The dominant symptom is a temperature of 39 degrees Celsius and chills. Fever lasting more than 3 to 4 days is the first diagnostic sign of leptospirosis.
The peak period is also called the period of organ damage. This name reflects the essence of this period, since at this moment serious damage to the liver, kidneys and brain occurs. This period is characterized by increased mortality. The recovery period corresponds to the restoration of vital functions, such as respiratory, cardiovascular and urinary.

Diagnosis of leptospirosis

Examination by a doctor

An examination by a doctor consists of examining and interviewing the patient. Based on the information received, the physician makes a preliminary conclusion about the likelihood of leptospirosis. To refute or confirm a preliminary diagnosis, the doctor prescribes a series of tests.

Patient interview
The purpose of the survey is to determine possible routes of human infection with leptospirosis. The most common method of infection is water, so the doctor is interested in whether the patient has visited natural bodies of water. Leptospirosis can also be contracted through ingestion of contaminated foods. There is a high probability of contact infection, especially if there are even small cuts, scratches, or abrasions on the patient’s skin. Often this disease is of a professional nature, so the doctor is also interested in the patient’s field of activity.

Questions your doctor may ask are:

• whether the patient swam in open water;
• whether the patient used water from open reservoirs for washing dishes or other household items;
• whether the patient had contact with wet soil;
• whether the person who came to the reception was engaged in cutting raw meat;
• whether the patient is an employee of a veterinary clinic, livestock farm, or pet store;
• whether the patient has a dog or other pets.

Patient complaints characteristic of leptospirosis
Leptospirosis is characterized by an acute and sudden onset of the disease, in which the patient is bothered by muscle pain, high body temperature, chills, and weakness. Most often, pain occurs in the calf muscles, in the abdomen, chest, and back. When you feel the disturbing parts of the body, the pain intensifies. The patient may also experience headaches, dizziness, and insomnia. On days 3–6 after infection, all symptoms intensify, in 50 percent of patients ( especially children) a symmetrically located rash appears on the body. Some patients are bothered by nosebleeds and hemorrhages on the mucous membranes and skin. Some patients complain of vomiting, increased tone of the neck muscles, and an increase.

Patient complaints specific to leptospirosis are:

• temperature 39 – 40 degrees;
• dry tongue;
• pain in the eyes;
• lethargy;
• muscle aches;
• heavy gait;
• sleep problems;
• decreased amount of urine excreted;
• discoloration of stool.

On the 5th – 6th day of the development of the disease, intoxication increases, as a result of which patients begin to complain of increased headaches, strong urge to vomit, and bleeding gums. In some cases, patients are bothered by the symptoms of jaundice, which manifest themselves in the form of yellowing of the eye sclera and a bright yellow tint to the skin.

External examination of the patient
Patients with this disease are characterized by a typical appearance and a number of symptoms that the doctor identifies by examining the patient’s skin and throat, listening to the heart and lungs.

External diagnostic signs of leptospirosis include:

• puffy face;
• yellow coloration of the sclera;
• redness of the facial skin or icteric coloring of the face;
• enlarged lymph nodes located under the lower jaw and behind the neck;
• fear of light.

When listening to a patient's heart, the doctor detects increased heart rate, decreased tone of the heart muscles, and muffled tones. Dry wheezing may be heard over the lungs. With the development of leptospirosis pneumonia or bronchitis, the physician observes dullness of lung sounds and pain in the chest.
In addition to the examination, the doctor palpates the abdomen, during which the spleen is felt. The liver is enlarged and moderately painful on palpation.

Pathologies that a doctor can detect when examining a patient’s throat and mouth include:

• brown coating on the tongue;
• moderate redness of the tonsils;
• rash on the soft palate;
• hemorrhages on the arches, tonsils, palate.

During an examination of the skin of a patient with suspected leptospirosis, the doctor may identify a rash that is symmetrically located on the torso and limbs. The rashes are similar to the manifestations of diseases such as measles, rubella, and less commonly scarlet fever. There is also macular ( spotted) a rash that merges into separate elements forming erythematous fields. This type of rash occurs most often and disappears after 1 to 2 days. After the exanthema disappears ( rash) Upon examination, the doctor may detect pityriasis-like peeling of the skin.
In some patients, a herpetic rash may appear in the area of ​​the sinuses and lips.

Laboratory research

Laboratory diagnostic methods are integral in making the diagnosis of leptospirosis.

Laboratory diagnostic methods for leptospirosis are:

• clinical and biochemical blood test;
• microscopic method;
• bacteriological method;
• biological method;
• serological diagnostic methods;

Clinical and biochemical blood test
A blood test is one of the first tests a patient undergoes if an infectious disease is suspected. A general blood test is not a specific method, since it does not determine the type of pathogen. However, it indicates the presence of an infectious process in the body. This is supported by parameters such as the total number of leukocytes and erythrocyte sedimentation rate. An increase in these two indicators indicates an infectious process in the body.

A biochemical blood test is also not specific for leptospirosis. However, deviations in it indicate damage to the relevant organs. Thus, an increase in the level of liver transaminases, such as alanine aminotransferase ( ALAT) and aspartate aminotransferase ( ASAT), indicates liver damage. With the development of jaundice, a biochemical blood test reveals an increased concentration of bilirubin ( more than 20 millimoles per liter).

With leptospirosis, the following parameters of the biochemical blood test change:

• alanine aminotransferase - more than 41 units per liter;
• aspartate aminotransferase - more than 40 units per liter;
• bilirubin – more than 17.1 micromol per liter;
• alkaline phosphatase - more than 270 units per liter;
• 5-nucleotidase – more than 17 units per liter.

These are the main indicators, the increase of which indicates liver damage due to leptospirosis.

Microscopic method
This method allows you to identify the causative agent of leptospirosis ( Leptospirra Interogans), directly in the native material and examine it under a microscope. The smear is pre-stained using various methods. For leptospirosis, this method is Romanovsky-Giemsa staining, which stains leptospira pink. In addition to the Romanovsky method, the silvering method is used. This method stains the bacteria brown.

The microscopy method is an express method that allows you to quickly and inexpensively identify the pathogen. It consists of two stages - collecting material and preparing the drug. For the first stage, the patient's blood, urine or cerebrospinal fluid is used. The taken material is applied to a glass slide, fixed and stained. The colored material is examined by a laboratory assistant under a microscope. For this purpose, the method of direct dark-field microscopy is used.

Leptospira can be detected in the material being studied already in the first days of the disease. In urine and spinal fluid on days 7–10 of the disease. Despite its ease and accessibility, the method has its drawbacks. It gives negative results more often than others.

Bacteriological method
The bacteriological method consists of studying pathogenic bacteria by inoculating material on nutrient media. It allows you to identify the pathogen in its pure form and study its properties. Leptospira grows on media containing serum, so nutrient media with the addition of rabbit blood serum are used for their cultivation. After inoculating the test material ( blood, urine) the culture is placed in a thermostat, where optimal conditions for the growth of Leptospira are created. Such conditions for Leptospira are high humidity, temperature of 30 degrees Celsius and acidity in the range of 7.0 - 7.4. Leptospira grows very slowly, and their growth is detected only on days 7–10, which is a significant disadvantage of this method.

Biological method
This method involves isolating the causative agent of the disease by infecting laboratory animals that are susceptible to it. For leptospirosis, such animals are hamsters, guinea pigs, and rats. The method is not widespread and is more historical.

Serological diagnostic methods
These methods are basic in the diagnosis of leptospirosis. They are based on identifying specific antibodies in the patient’s blood. These antibodies are synthesized by the human immune system in response to Leptospira entering the body. For leptospirosis, microagglutination reactions are used ( RMA) and compliment binding ( RSK).

The microagglutination reaction consists of detecting the titer of antibodies in the blood ( or rather, in the serum) patient. Agglutination is the sticking together and, as a consequence, precipitation of bacteria. For this purpose, special strains of Leptospira are used on the 10th – 12th day of their growth and the patient’s serum. Leptospira cultures are diluted to certain concentrations. The reaction is carried out either in test tubes or in special wells-plates, which are placed in a thermostat for 2 hours at a temperature of 30 - 37 degrees Celsius. Agglutination of leptospira, that is, their gluing together, looks like the formation of balls. The highest dilution of serum that will cause leptospira to stick together is called the titer. The reaction is considered positive with a titer of 1 in 100. If the diagnosis is carried out in the second and third weeks of the disease, then the diagnostic titer can reach 1:100,000. This means that leptospira are present in the maximally diluted serum.

The complement binding reaction involves the formation of an antigen-antibody complex and the addition of a compliment to it. If the antigen-antibody complex is not formed, then the compliment remains free. The first stage of the reaction involves mixing the patient's serum, which contains antibodies to Leptospira, and standard antigens. If there are no antibodies in the serum, then the formation of the complex will not occur, and the complement will remain free. If a person is sick with leptospirosis and there are antibodies in his serum, then they will specifically bind to the antigens and attach a compliment to themselves.

To find out whether the compliment remained bound or was attached, a mixture of sheep erythrocytes and antibodies sensitized to it is added to the test tube. If the compliment is associated, then nothing will happen to the red blood cell-antibody mixture. When the compliment is free, it attaches to red blood cells and destroys them. A reaction called “erythrocyte hemolysis” occurs. Visually, this is manifested in the formation of a clot at the bottom of the test tube.

Polymerase chain reaction ( PCR)
The PCR diagnostic method is the most accurate method. Its specificity reaches 95–99 percent, and the duration of its implementation takes no more than a day. The method involves identifying fragments of Leptospira genetic material in biological material. Any body fluids can be used as material ( blood, urine, spinal fluid), brush strokes, pieces of tissue. The reaction is carried out in an apparatus called a thermal cycler, with the addition of many special reagents. The essence of the method is the synthesis of a large number of strands of deoxyribonucleic acid ( DNA) based on small pieces of it. Thus, even if minor DNA fragments are present in the material being tested, it is possible to identify the pathogen.

At the first stages, these fragments are identified. Then, based on them, a DNA strand is completed using enzymes. Then the number of threads is multiplied to several thousand copies. At the final stage, the DNA found is identified. Since the DNA molecule is unique and inimitable for each bacterium or virus, the specificity of the method and its sensitivity reaches 99 percent. PCR very rarely gives false positive results. A significant disadvantage of this method is its cost.

Treatment of leptospirosis

Detoxification of the body

Detoxification for leptospirosis is necessary to remove leptospira and their toxins from the body. For this purpose, various saline and plasma-substituting solutions are used. At the same time, the volume of circulating blood is replenished, since due to the development of hemorrhagic syndrome in leptospirosis, loss of blood and body fluid occurs.

Drugs that are used to detoxify the body

A drug	Mechanism of action	How is it prescribed?
Hemodez	Thanks to the potassium, calcium, magnesium and sodium included in the drug, it restores the acid-base balance and regulates the water-electrolyte balance. Restores plasma volume.	Intravenous drip administration is recommended, 50 drops per minute. The daily volume is calculated based on the condition and age of the patient. A single dose should not exceed 500 ml.
Enterodesis	The active substance of the drug is a high-molecular compound - povidone. It binds and removes toxins, thereby providing a detoxifying effect.	The drug is taken orally, two hours after eating. The sachet with the drug is diluted in 100 ml of cold water. It is recommended to take 2–3 sachets of the drug per day.
Mannitol	Has a diuretic and anti-edematous effect. The diuretic effect is used to quickly remove Leptospira toxins from the body. The principle of action is to increase the osmotic pressure of plasma and restore the volume of circulating blood. Due to this, diuresis increases ( urine volume), which is reduced in leptospirosis. Toxins, leptospira and metabolic products of the body are excreted along with urine. More than 80 percent of the administered drug is excreted by the kidneys within 3 hours.	At the rate of 0.5 grams per 1 kg of weight, the drug is administered intravenously by drip or stream ( depending on the volume of fluid lost). 10, 15 and 20 percent solutions are introduced. Before use, it is recommended to warm the drug to 30 degrees in order to prevent sedimentation.
20 and 40 percent glucose solution + furosemide	The combination of these drugs provides an artificial increase in urine output. Glucose stimulates the transition of fluid into the bloodstream, thereby restoring the volume of circulating blood. Furosemide has a rapid diuretic effect.	The maximum dose of 40 percent glucose is 250 ml per day; 20% glucose – 500 ml per day. Solutions are administered intravenously, 30 drops ( for 20 percent glucose) and 20 drops ( for 40 percent glucose) in a minute. At the end of intravenous administration, 20–40 mg of furosemide is administered.
Polysorb	Absorbs toxins, toxin-like substances and bacteria from the gastrointestinal tract. Also sorbs ( absorbs on its surface) metabolic products such as bilirubin. Thus, it reduces the increased concentration of bilirubin in the blood. Particularly effective for the icteric form of leptospirosis.	Taken exclusively orally, an hour before meals. From one to two tablespoons of the drug ( 3 – 6 grams) is stirred in 150 ml ( half a glass) cold water. The average daily dose is 12 grams ( 4 spoons).

Treatment with antibiotics

Antibiotic therapy along with the introduction of specific serum is the basic treatment of leptospirosis. Penicillin preparations are mainly used, and in case of intolerance, antibiotics from the macrolide group.

Antibiotics that are used in the treatment of leptospirosis

A drug	Mechanism of action	How is it prescribed?
Penicillin	It disrupts the formation of Leptospira cell wall components, thus provoking their destruction.	The dose depends on the severity of the disease. For moderate severity, the daily dose is 10,000,000 – 12,000,000 units ( units of action); in severe forms that occur with the development of meningitis - 24,000,000 units. The dose chosen by the doctor is divided into 4–6 doses and administered intramuscularly strictly according to the clock.
Erythromycin	Binds to ribosomes ( cell organelles), blocking the synthesis of proteins necessary for the life of bacteria.	500 mg is administered intravenously every 6 hours. The maximum dose is 4 grams.
Doxycycline	Has a wide spectrum of action. It disrupts protein synthesis, inhibiting the growth of Leptospira.	Taken orally 100 mg twice a day. In exceptional cases, the dose reaches up to 200 mg twice a day.

Plasmapheresis

Plasmapheresis – extracorporeal ( outside the body) a procedure aimed at removing toxic components of the blood. In leptospirosis, such components are toxins and metabolic products of the body. This procedure is used for the development of renal and liver failure. It consists of taking part of the patient’s blood and purifying it. Cleansing occurs by removing the liquid part of the blood - plasma, which contains all the toxins. The formed elements of blood (leukocytes, platelets, red blood cells) are returned back to the patient’s bloodstream, and the volume of collected plasma is replenished with physiological solutions and blood substitutes. Thus, cleansing the blood of toxins occurs as a result of removing the plasma, which contains these toxins. The elements of blood remain intact.
Depending on the technique of this procedure, there are several options for plasmapheresis.

The following plasmapheresis methods are distinguished:

• Filtration method. The principle is based on plasma filtration through special plasma filters. The filter is a fibrous membrane with many porous fibers. Blood cells do not pass through these pores.
• Gravity method. This method is based on the principle of centrifugation, which consists in separating heterogeneous parts into individual components based on density using centrifugal forces.
• Cascade method. It consists of repeated filtration of plasma through a special filter that allows only blood albumin to pass through.

In addition to plasmapheresis, extracorporeal methods such as hemodialysis, hemosorption, hemofiltration and others are used.

Introduction of specific serum

For the treatment and prevention of leptospirosis, specific serum or gamma globulin is used. Treatment of leptospirosis with these drugs is most widespread in the post-Soviet countries.

When is it appointed?
Specific serum is prescribed to quickly compensate for the immunological deficiency of the patient’s body. Most often, insufficiency of immune defense is observed in the initial stages of the disease, when the body has not yet had time to produce the required amount of antibodies to Leptospira. This also occurs when the body’s immune resources are rapidly depleted in people with immunodeficiency, severe chronic diseases, and the elderly.

Antileptospirosis serum and gamma globulin have strict indications for use.

The main stages of the disease when specific serums and globulins are prescribed are:

• acute period of clinical manifestations;
• severe forms of leptospirosis with severe damage to organs and systems;
• acute organ failure ( renal, cardiac);
• secondary bacterial infections ( meningitis, encephalitis, myocarditis).

Also, specific immunization is prescribed to persons located in epidemic foci of leptospirosis infection.

What does the serum contain?
Antileptospirosis serum contains high titers ( concentrations) antibodies to the main species of Leptospira that cause disease in humans.
These serums are created based on animal blood ( horses) or people artificially infected with pathogenic Leptospira. To achieve high antibody titers, large doses of leptospirosis antigens are gradually introduced into the animal/human body. In response to foreign antigens, the body produces a large number of antibodies that neutralize them. Heterologous sera are created based on animal blood containing the highest antibody titers. Sera obtained from human blood are called homologous.

By processing anti-leptospirosis serum and precipitating its protein fractions containing antibodies, gamma globulin is obtained. In other words, gamma globulin is a highly purified “whey concentrate”.
Specific serums and gamma globulin are available in ampoules of 5 and 10 milliliters. The drugs are administered intramuscularly for three days in a row, 5 milliliters. In severe forms of leptospirosis and secondary complications, the dose is increased to 10 milliliters.

What is the effectiveness for the disease?
The effectiveness of anti-leptospirosis serums and gamma globulin is quite high. Thanks to a large dose of specific antibodies, passive immunization is created, which ensures active fight against infection. However, the created “artificial” immunity is not permanent. The effect of serum antibodies lasts on average 5–6 weeks, after which they are destroyed.

Prevention of leptospirosis

Leptospirosis infection can be prevented by limiting contact with carriers of the disease, which are infected rodent pests, farm and domestic animals. Preventive measures to combat this disease can be divided into two groups. The first category includes rules for which the person himself bears responsibility. The second group includes activities, the organization and control of which is the responsibility of sanitary and epidemiological control authorities and health care institutions.

The rules for personal prevention of leptospirosis are:

• timely vaccination of animals;
• detection and treatment of disease in domestic animals;
• extermination of rodents and prevention of their appearance;
• implementation of preventive rules during agricultural work;
• compliance with safety rules when relaxing in nature;
• compliance with sanitary and hygienic requirements at the workplace in case of professional belonging to a risk group;
• immunization against leptospirosis.

Vaccination of animals against leptospirosis

Immunization of animals against leptospirosis is an effective measure that will protect humans and animals from this disease. Vaccination methods depend on the conditions in which the animal was acquired. If the owner knows for sure that the animal is not infected with Leptospira ( when purchased from a nursery or from a breeder), a standard vaccination procedure is carried out. If the animal was purchased by hand or picked up on the street, passive immunization is carried out, in which a special hyperimmune serum is placed before the vaccine.

Detection and treatment of leptospirosis in pets

Pet owners are at risk for leptospirosis, as the source of infection is often a sick animal. The main routes of infection are skin contact with water that is contaminated with secretions, saliva or urine of a sick animal. Timely identification of the symptoms of the disease in an animal and adequate treatment will allow a person to avoid infection with Leptospira.

Destruction and protection from rodents

Rats and mice can cause leptospirosis in humans. Most often, people get sick from rat bites. The source of infection can be food or drink that has contained urine, saliva or secretions of rodents. Dogs that hunt them can also cause leptospira infection in humans. Therefore, for the purpose of prevention, rodent control should be carried out, destroying existing ones and preventing the appearance of new rats and mice.

Measures to prevent rodents include:

• cleaning utility rooms, attics and basements;
• timely garbage removal;
• sealing cracks and openings through which animals can enter the room;
• use of ultrasonic and other devices to repel rodents.

Prevention of leptospirosis when working in garden plots
A country house or dacha is a potential source of Leptospira infection. Infection can occur when working with soil that contains secretions from carrier animals. You can also become infected by using dishes or household items contaminated by infected rodents. The likelihood of infection increases if rat or mouse excrement is found in the home or outbuildings. To prevent leptospirosis, before the start of the summer season, it is necessary to carry out wet cleaning using alkaline solutions.

Areas that need to be cleaned and treated are:

• basements;
• attics;
• sheds;
• garages;
• residential buildings;
• utility buildings;
• undeveloped area adjacent to the house.

Floors, furniture, dishes and household items should be treated with a disinfectant. Areas around the house must be cleared of dry plants, old hay, and dead wood. This waste should be burned or taken to designated landfills. Before carrying out these procedures, you must wear rubber gloves, since infection can be introduced even through minor damage to the skin. Protective gowns, boots and masks should also be used. If you find live rodents or their corpses, you should refrain from trying to catch them or touch them with your hands.

Preventive measures on personal plots include:

• destruction of all products spoiled by mice or rats;
• refusal to drink raw water;
• storing food and water in tightly closed containers;
• carrying out excavation work wearing gloves;
• preventing the formation of landfills on a summer cottage and in its immediate vicinity.

Rules for spending time in open areas

During active recreation in nature, a person may encounter natural foci of leptospirosis, where pathogens circulate in the population of wild animals. Zones of potential infection with Leptospira are located mainly on low relief of forests and river valleys. Reservoirs with standing water and adjacent areas are also dangerous.

Places where there is a high probability of infection with leptospirosis are:

• wet grassy areas;
• thickets of sedge, cattail, reed;
• wet floodplain meadows;
• swamps;
• forest edges and wet deforestation.

Carriers of Leptospira in natural conditions are field mice, rats, moles, and shrews. Infection of people in natural foci most often occurs in summer and autumn during fishing, hunting, hiking, and outdoor recreation. Avoiding infection with Leptospira will help by following the rules of personal hygiene, refusing to use water from lakes and rivers for washing dishes or food, and wearing rubber shoes when fishing and hunting. You should avoid swimming in bodies of water where prohibiting signs are posted on the banks. You should also not swim in those lakes and rivers on the banks of which cows and other farm animals are grazing.

Taking precautions in the workplace

In addition to natural foci, there are economic zones in which the likelihood of infection with leptospirosis is increased. The formation of such conditions is facilitated by the treatment, breeding and maintenance of animals that are carriers of Leptospira. Animals excrete pathogens along with their urine, contaminating the soil, water, pastures, feed and other environmental objects through which people become infected. You can become infected with Leptospira through contact with animals, repairs and cleaning of the premises in which they are kept, or eating or drinking in the workplace, into which infected material may come into contact. The incidence of leptospirosis in economic outbreaks has no seasonality. The likelihood of infection is higher in those farms where rats and rodents are present. The danger also increases in facilities that are in unsatisfactory sanitary condition.

The high-risk group includes representatives of the following professions:

• employees of veterinary clinics;
• dog breeders;
• pig farmers, milkmaids, calf workers;
• employees of meat processing plants and livestock farms;
• people transporting animals;
• workers of circuses, zoos, equestrian sections.

Also, individuals who, due to their profession, often come into contact with synanthropic rodents ( living near or with people). The most common source of infection in this case is the gray rat. This risk group includes such professions as miners, miners, employees of fish farms, workers in warehouses and wastewater treatment plants.

Measures to prevent leptospirosis infection in the workplace are:

• wearing rubber shoes and gloves, special overalls or gowns, rubberized aprons, hats;
• treating workwear at the end of the working day with special disinfectants;
• storage of work clothes and shoes in specially equipped rooms;
• refusal to take food and water in the workplace;
• storing drinking water and food in closed containers;
• disinfection and washing of hands with soap before eating and at the end of the working day;
• eating food in specially designated areas.

Persons constantly working on farms where the risk of contracting leptospirosis is increased should be vaccinated against this disease.

Immunization against leptospirosis

To form active immunity in a person who is at risk of infection with Leptospira, vaccination is carried out. For vaccination, a drug is used that consists of several of the most common types of leptospirosis pathogens. The vaccine is injected into the subscapular region twice. The volume of the first dose is 2 milliliters, the second ( carried out after 7 – 10 days) – 2.5 milliliters. The immunity of people who receive the vaccine lasts no more than a year. Therefore, people who are constantly in the territory of natural or economic outbreaks with an increased risk of infection must be vaccinated annually. The interval between vaccination against leptospirosis and vaccines against other diseases should be at least 30 days for adults and at least 60 days for children. 24 hours before vaccination, you must give up alcohol and undergo an examination by a doctor, who will make a conclusion about admission to vaccination.

State-controlled preventive measures against leptospirosis

Sanitary and epidemiological surveillance of leptospirosis, regulated by government agencies, is a series of activities aimed at reducing the incidence rate in the country. The implementation of preventive measures is entrusted to medical and preventive institutions, sanitary and epidemiological organizations and veterinary control authorities.

The role of medical and preventive enterprises in the prevention of leptospirosis
Public health officials are responsible for identifying human cases early to prevent outbreaks of leptospirosis.

Measures to prevent mass infection with leptospira, carried out by doctors, are:

• timely diagnosis of morbidity cases among people;
• immediate hospitalization of persons with suspected leptospirosis;
• registration, recording and maintaining statistics of cases of leptospirosis infection;
• notification of registered cases to relevant authorities;
• implementation of dispensary supervision for six months for persons who have had this infection.

Identification of patients with leptospirosis is carried out on the basis of symptoms of the disease and factors present in the anamnesis that accompany infection ( previous swimming in a pond, belonging to an occupational risk group, visiting foci of infection). Employees of medical institutions must notify sanitary and epidemiological control authorities of all suspicious cases within 12 hours. If the diagnosis changes or is clarified, an emergency notification must also be sent.

Sanitary-epidemiological and veterinary control bodies
Receiving information about group or occupational cases of leptospirosis, employees of sanitary-epidemiological and veterinary surveillance authorities organize a number of activities in order to determine the source of infection and prevent an outbreak of infection.

Measures to prevent leptospirosis, for which representatives of these bodies are responsible, are:

• conducting a special investigation in cases of occupational or group disease;
• survey of people working or living near infection sites;
• removal of samples from the environment for laboratory research;
• introducing a ban on products related to the source of infection;
• restriction of work and stay of people in potentially hazardous areas;
• carrying out disinfection and deratization;
• organization of events on the prevention of leptospirosis among the population;
• organization of vaccination of persons at risk.

Hygienic education of the population is an effective measure for the prevention of leptospirosis. Providing detailed information about the main symptoms, routes of infection and the need to take precautions is carried out taking into account the scope of the person’s professional activity.

Microbes are considered the simplest organisms among all life forms. However, they have not ceased to arouse the interest of scientists for two thousand years. Plants and animals cannot boast of such a variety of species. Most bacteria exist on their own and do not harm humans. Some species have adapted to live successfully in the bodies of reptiles, birds and mammals. And only a small part of bacteria causes diseases in humans and animals at the same time. Leptospirosis is one of these diseases.

Leptospirosis: a disease of humans and animals

Leptospirosis is an infectious disease of animals and humans, accompanied by fever, liver and kidney damage.

The causative agent of this disease is the microbe Leptospira interrogans. There are several varieties of bacteria, each of which primarily lives in the body of certain animals:

Leptospirosis is found on all continents. Slightly more common in the tropical zone. The main foci of leptospirosis were found in riverine areas. There are many such geographical areas in Russia. The incidence of leptospirosis is recorded in 50 regions of the country. A particularly unfavorable situation has developed in the Krasnodar and Altai territories, Kurgan and Orenburg regions, and the Republic of Sakha-Yakutia. Here, rodents play the role of the main source of infection. In addition to natural foci of leptospirosis, there are also agricultural ones. The disease is common on livestock farms where cattle, goats, pigs, horses, as well as fur-bearing animals (mink, nutria, fox) are bred.

Leptospirosis is more often recorded in several regions of the Russian Federation The causative agent of leptospirosis prefers to live in humid areas. It calmly survives the cold season in ponds and wetlands.

When contacted with food, the bacterium retains its properties for two days and survives freezing. Leptospira especially does not tolerate sunlight, high temperatures, or drying out.

Under a microscope, Leptospira actually resembles a spiral. The name of the bacterium comes from two Latin words: leptos - gentle and spiro - spiral.

Leptospirosis - video

Leptospirosis most often occurs in people living in natural foci of the disease. In addition, the risk group includes workers on livestock farms, agricultural production, meat processing plants, veterinary services, shepherds, and dog breeders.

In tropical countries, workers in rice, rubber and cane plantations are getting sick. The incidence of leptospirosis rises in the summer-autumn season.

Leptospirosis is a zoonotic infectious disease

Synonyms of the disease: swineherd's disease, bathers' fever, water fever, mud fever, Japanese seven-day fever, Weil-Vasiliev disease.

Classification

Sources of infection are animals suffering from leptospirosis. You cannot become infected from a sick person. Most often, the infection enters the body when swimming in an unorganized body of water, where bacteria enter with the urine of rodents and other animals.

Leptospira penetrates through the mucous membranes of the pharynx, nose, conjunctiva of the eyes, intact skin, by swallowing raw water, and walking barefoot on the grass. Veterinary workers and livestock farm workers most often become infected through contact from sick animals. Leptospira can also enter the body through food. No changes occur at the site of microbe introduction. The bacterium seeks to enter the general bloodstream. From there, leptospira penetrates the lymph nodes, liver, and spleen. The microbe releases toxic substances that destroy liver and kidney cells.

In the first case, a large amount of the coloring pigment bilirubin is released into the blood, resulting in a jaundiced coloration of the skin and mucous membranes. Affected kidneys stop properly filtering blood and producing urine.

Leptospira causes death of renal tubular cells Vessels, especially those of the smallest diameter - capillaries, suffer no less from the influence of the toxin. The vascular wall becomes thin, resulting in the formation of ruptures and areas of hemorrhage.

They are localized both inside the skin and other organs. A certain amount of Leptospira can enter the membranes of the brain through the bloodstream. The typical result is inflammation - meningitis.

Leptospira damage the walls of blood vessels Leptospira infection is necessarily noted by the immune system. White blood cells (leukocytes) move from the bloodstream to foci of inflammation in the liver, kidneys, spleen, and meninges. Part of the Leptospires is absorbed and digested by leukocytes. Specific antibody proteins are produced against the remaining microbes.

The rate of their formation increases under the influence of elevated body temperature during the febrile period of the disease.

Symptoms and signs

Leukocytes are the body's main defenders against infections. Between infection and the appearance of the first symptoms of the disease, there is necessarily a period of time called the incubation period. Its duration ranges from three to thirty days. Most often, symptoms appear one to two weeks after infection. Leptospirosis is a disease with many faces. The large number of organs involved causes the varied symptoms of this infection.

Their severity depends entirely on the form of the disease.

Symptoms of leptospirosis - table	Scene	Appearance time symptoms	Fading time symptoms
General blood flow	fever; headache; aches in muscles and joints; insomnia; areas of hemorrhage on the skin; skin redness; skin rash.		Second week of illness
Heart muscle	rapid pulse; low blood pressure; interruptions in heart function.	At the end of the incubation period
Kidneys	lower back pain; painful urination; cloudy urine; impurity; decrease in the amount of urine per day.	Second week of illness	Third or fourth week of illness
Meninges	headache; nausea; vomit; neck muscle tension; confusion.	Second week of illness	Third or fourth week of illness
Liver	jaundice; liver enlargement; minor hemorrhages on the skin.	Second week of illness	Third or fourth week of illness
The lymph nodes	enlarged lymph nodes; soreness of the lymph nodes.	Second week of illness	Third or fourth week of illness
Spleen	enlarged spleen;	Second week of illness	Third or fourth week of illness
Lungs	dyspnea; bluish tint of the skin; hemoptysis.	Second week of illness	Third or fourth week of illness

Symptoms of leptospirosis - photo gallery

Jaundice is a sign of liver damage Minor hemorrhages on the skin are the result of a microbial toxin
A bluish tint to the skin is a sign of oxygen deficiency in the blood
Inflammation of the meninges leads to excessive muscle tension Liver enlargement is a typical sign of infection
Enlarged lymph nodes are one of the manifestations of leptospirosis

Diagnostic methods

Detection of leptospirosis is a task for an experienced infectious disease specialist. To make a correct diagnosis, an external examination, laboratory examination of biological fluids of the body and data from instrumental methods are used:

• The doctor receives information for a correct diagnosis during an external examination. The infectious disease specialist must pay attention to the icteric color of the skin, enlarged lymph nodes, areas of minor hemorrhages, pain when palpating the liver, kidneys and spleen;
• infection leads to a significant change in blood composition. On the one hand, a high leukocyte count and an acceleration of ESR (erythrocyte sedimentation rate) indicate a pronounced inflammatory process. On the other hand, there are signs of anemia - low levels of red blood cells and hemoglobin; With leptospirosis, a deficiency of red blood cells (anemia) is detected in the blood
• Blood biochemistry will tell the doctor about the condition of the liver and kidneys. High levels of bilirubin, AST and ALT indicate liver cell death. Excess urea and creatinine in the blood is formed due to impaired kidney function;
• A urine test also indicates liver and kidney damage. A simple general analysis method allows you to identify many substances that should not normally be present: bilirubin, protein, leukocytes, casts;
  Leukocytes in urine - a sign of inflammation
• symptoms of meningitis are a reason to collect cerebrospinal fluid using lumbar puncture (lumbar puncture). Protein, a large number of leukocytes are signs of inflammation of the meninges;
  Lumbar puncture is used to collect cerebrospinal fluid
• Microscopic examination of blood, cerebrospinal fluid and urine will allow you to detect bacteria of a characteristic appearance;
• growing Leptospira on a nutrient medium is a very lengthy and expensive process, so this method is rarely used;
• immune diagnostic methods - enzyme immunoassay and polymerase chain reaction - make it possible to detect antibody proteins against Leptospira in the blood and confirm the diagnosis;
• The ultrasound method allows you to assess the size and internal structure of the liver and spleen, and also identify areas of hemorrhage.
  Ultrasound is a safe diagnostic method

Leptospirosis must be distinguished from other infectious diseases accompanied by fever, hemorrhages on the skin, and jaundice:

Treatment methods

Any form of leptospirosis is a reason for hospitalization and observation by a specialist. Damage to several internal organs at once requires complex treatment using modern medications and procedures for cleansing the body of toxins and other harmful substances.

Medicines to fight infection

To eliminate the bacterium and the consequences of its vital activity, modern medicines are required. They affect the sick body from several sides at once: they destroy the microbe, eliminate fever, anemia, symptoms of intoxication, and the consequences of liver and kidney damage.

Medicines - table

Pharmacological agents	Mechanism of action	Examples of drugs
Antibiotics	Disorder of functioning microbe	Ampicillin; Amoxicillin;
Solutions for intravenous infusions	Detoxification	Hemodez; Reamberin.
Non-steroidal anti-inflammatory facilities	antipyretic effect; analgesic effect; anti-inflammatory effect.	Paracetamol; Nise; Nurofen; Ketoprofen; Dexalgin.
Hemostatics	increased blood clotting; stopping bleeding.	Etamsylate; Gordoks;
Diuretics	Diuretic effect	Furosemide.
Vasoprotectors	Strengthening the vascular wall	Rutin; Troxevasin.
Steroid hormones	Anti-inflammatory effect	Metipred; Hydrocortisone.
Antihistamines	Antiallergic effect	Loratadine; Suprastin; Tavegil.
Hepatoprotectors	Liver cell restoration	Karsil; Heptral; Phosphogliv.

Medicines for the treatment of leptospirosis - photo gallery

Doxycycline is an antibacterial drug Dicynone is used to stop bleeding Lasix is ​​a diuretic drug Essentiale forte N will help restore liver cells Prednisolone is a steroid hormone Sodium chloride solution is used for intravenous infusions

Methods of artificial blood purification

Leptospirosis differs from many infectious diseases in that almost all of its manifestations are caused by the action of a microbial toxin and accumulated waste - bilirubin, urea, creatinine.

Modern medicine has developed a number of technologies that can be used to artificially cleanse the blood of these harmful substances:

The principle of the hemodialysis procedure - video

Diet Damage to the liver and kidneys due to leptospirosis requires a special diet. To facilitate the functioning of the liver, all irritating dishes and foods, including those prepared by frying, should be excluded from the diet. It is preferable to cook meat and vegetables by boiling and baking. Table salt and liquid are limited depending on the degree of renal failure.

• It is recommended to consume the following foods and dishes:
• vegetable soups and side dishes;
• dietary meats - poultry, rabbit;
• berry desserts, fruit drinks and compotes;
• bran bread;
• dairy products;

porridge from buckwheat and millet groats. Vegetables are the basis for side dishes and first courses Berry dessert contains vitamin C Bran bread is a source of vitamins Fermented milk products contain calcium Buckwheat porridge is useful for leptospirosis

It is advisable to boil or bake turkey fillet

• Foods high in fat, salt, spices and other flavor enhancers should be excluded from the diet:
• fatty meats, lard and bacon;
• sausages and smoked delicacies;
• canned meat and fish;
• sorrel and asparagus;
• chocolate;
• baked goods;
• carbonated drinks;

alcohol. Fat puts a lot of stress on the liver Smoked foods contain excess salt Chocolate contains a lot of sugar and fat Sweet baked goods cause bile secretion

Alcohol has a negative effect on the liver and kidneys

Complications and prognosis The prognosis for treatment of leptospirosis is individual and depends on the severity of symptoms. The defining moment is the appearance of signs of renal and liver failure.

In addition, other complications may develop: Single cases of leptospirosis rarely lead to an unfavorable outcome (1–2% of cases).

During a period of rising incidence, this figure can reach 15–20%.

Prevention

Kidney failure - video

Leptospirosis is not only an occupational disease of livestock workers and veterinary workers. You should remember the danger of contracting an infection when swimming in an unknown body of water, drinking raw water and thermally unprocessed foods. Timely seeking help at the first symptoms of the disease significantly reduces the risk of complications and adverse outcomes.