LEPTOSPIROSIS

Leptospirosis is an acute generalized infectious disease, characterized by extensive vasculitis, caused by spirochetes of the genus Leptospira. It is primarily disease of wild and domestic mammals; humans are infected only through direct or indirect contact with animals.

Historic reference ^

A. Weil (1886) was the first who described leptospirosis as an independent disease, four cases with a high temperature, jaundice, hemorrhages and the renal affection.

R. Virchout (1865) considered the described disease as a kind of typhoid fever and called it "typhus biliosus" differentiating it from "katarrhalischen icterus".

In 1888 in the book "Infectious Jaundice" S.P.Botkin's disciple N.K.Vasiliev informed about twelve cases of a similar disease but did not paid much attention to the character of the temperature, the expressiveness of jaundice, the time when hemorrhages and the renal affection appear, he comes to the conclusion that the new disease is different from typhoid fever and catarrhal jaundice.

For a long time leptospirosis was divided into icteric and non-icteric forms. The first description of non-icteric leptospirosis was given by W.A.Bashenin in 1928, he suggested naming me disease "water fever".

Leptospirosis is registered in many countries.

Etiology

The leptospirosis pathogen belongs to the genus of Leptospira nogychi and can be divided into 2 kinds - parasitic and saprophytic. There are hundreds of serotypes in each kind. The body of the leptospira consists of a long axis thread which is covered with a cytoplasmatic spiral that has a three-layer membrane. The average length of leptospiras is 10-14 mkm, the number of cons -10-12. There are no spores or capsules. Leptospiras have energetic and complex movements. This explains their high invasive ability. Leptospiras do not get well painted with common aniline dyes. Some special liquid media containing animal (rabbit) serum are used to cultivate leptospiras. Leptospiras are unstable in the environment but are adapted to living in water.

The leptospira life time in water oscilates within wide limits - from several days to many months depending on pH, the salty composition and the microflora of the reservoirs.

It has been discovered that leptospiras have hemolysin and also lipases that can have a cytotoxic influence on the organs and tissues which are rich with lipids. There is endotoxin in the leptospira cells.

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The modem classification of leptospiras is based on their antigenic structure. There have been discovered 200 serovars united in 25 serological groups.

There are two active serologic complexes among the antigens of leptospiras each of them has a complex set of components. One of them is situated on the cell surface and determines its typospecific qualities,the other - in the depth of the microbe and characterizes genospecific peculiarities of leptospiras.

The vital capacity of leptospiras in the environment depends on many factors. There is a considerable discrepancy in the whimsicality of leptospiras (the necessary conditions of their survival are high humidity, warmth, pH of the water and soil 7.0-7.4, the limited amount of salt). In the water of the rivers, pools, lakes and marshes leptospiras remain viable for 5-10 days but in the sea water they die in several hours. Leptospiras remain viable in the damp soil up to 270 days, in dry soil - not more than 3 days. Leptospiras can easily endure low temperatures and remain viable during prolonged freezing,however,they quickly die when warmed, dried if exposed to salt or acid.

Epidemiology

Leptospirosis is a zoonotic infection. The source of the infection is animals wild, domestic and game animals (pigs, cattle, foxes, white foxes, nutrias and others). They form anthropurgias foci.

The small mammals who live in the forests, near the reservoirs (volemice) play the main role in maintenance the leptospirosis foci. Their infection takes a form of a symptomless chronic process in the kidneys. Leptospiras multiply in the tubules of the kidneys and go out with urine.

The natural foci are situated in low lying areas. They are marshes, flood-lands, water-meadows, the marsh-ridden parts of the rivers and irrigation system, overgrown with bushes and abundant grassy vegetation. The infection of people in the natural foci is of a seasonal character (June-September), it usually occurs during the agricultural work (mowing the meadows, collecting hay, growing rice, flax, hemp and other abundantly irrigated crops, felling and during hunting, fishing, gathering mushrooms, drinking water and washing with water from the contaminated shallow reservoirs). The morbidity in the natural foci has a sporadic or group character. The development of natural resources, unorganized rest result in the immediate contact of people with nature and create an opportunity for infecting people with leptospiras. The natural foci are the source of infection for the domestic animals.

In recent years the gray rat has been playing a more important part in the epidemiology of leptospirosis, its infectedness has been proved in many countries of the world. For a long time leptospirosis was considered a disease of big cities, mainly ports. However, in the present situation the intensive processes of urbanization, creation of large cattle-breeding complexes, growing rice and other elements of the economic activity of man gave changed the ecology of the gray

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rat, so the anthropurgias foci of leptospirosis can be both in the rural areas and in the cities.

The foci which appear in the cattle-breeding industries as a result of bringing animals that are leptospira-carriers or infecting the cattle, pigs m the natural foci in the pastures, watering-places play the most important part in the epidemiology of the disease. The agricultural animals often have leptospirosis in the obliterated, symptomless form. That is why the sick animals are not isolated in time, they excrete leptospiras into the environment and infect water, forage, pastures, soil.

In many big cities, especially ports, there is a high rate of leptospirosis among the gray rats. This is the reason for the citizens to fall ill with leptospirosis if due to their occupation they contact sinanthropos rodents or the things contaminated by them.

The clinical symptoms of leptospirosis among dogs had been described before the pathogen was discovered and the term "leptospirosis" appeared. In 1898 in Stuttgart there was described a disease of dogs which had the following symptoms: hemorrhagic gastroenteritis, ulcerative stomatitis, renal affection (Stuttgart disease).

The infection is mainly transmitted from animals to humans by water. The contact way is considerably less important. The transmission of the infection through food is rare. Humans can be infected while swimming in the reservoirs, drinking water from them or using it for economic needs, during different kinds of the agricultural work in the marsh-ridden places, when. fishing. There have been described some cases of leptospirosis infection among the personal of the slaughter-houses, meat-packaging plants.

The leptospirosis incidence increases in June-September. In other months some sporadic cases are registered, which are not connected with the infection in the open reservoirs.

Leptospirosis can be considered as professional disease. The people who are involved in the agricultural work in the marsh-ridden places fall ill more often, they include cattle-breeders, the personal of meat-packaging plants, miners, dockers, plumbers.

There have been some cases when people fell ill after being bitten by a coypu rat, as well as the personal of the laboratories, who work with leptospiras. The susceptibility of people to leptospirosis is high. A typospecific immunity remains for a longtime after having the disease.

Pathogenesis

The pathogenesis of leptospirosis is characterized by changing several phases. The first phase includes the pathogen penetration and a short-time primary leptospiremia. The leptospiras penetrate the human organism through the skin of the mucous membranes, travel along the lymph tracts, penetrate the blood and then various organs - the liver, kidneys, adrenal glands, spleen, lungs and others. This phase lasts 7-20 days, it corresponds to the incubate period.

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The second phase includes secondary leptospiremia, it coincides with the beginning of the clinical manifestations of the disease, the generalization of the process. The leptospiras penetrate the organs and tissues with the blood flow again, fix on the cell surface (especially, in the kidneys, liver, adrenal glands), can overcome the hametoencephalic barrier. The leptospiras do not cause a destruction and they do not parasites intracutaneously. They stick to the cell surface, can stay in the inter-cell space.

The third phase is a phase of toxinemia that is accompanied by an expressed fever. The most important pathogenic factor of this phase is capillary toxicosis. The rupture of the capillary endothelium results in the diapedesious hemorrhages into various organs and tissues. It is clinically manifested as a hemorrhagic syndrome. Thrombocytopenia plays a part in the origin of the hemorrhagic syndrome, it is connected with the influence of the leptospira lipase on the phospholipids of thrombocytes membranes and their gluing together with the formation of the primary thrombocytous congestion. The vessels of the liver, kidneys, adrenal glands get affected most of all, there may develop Waterhause -Fridrichsen syndrome. The degenerative and partially necrotic changes of the liver parenchyma as well as hemolysis oferythrocytes under the affection of hemolysins are the cause of jaundice which has a mixed character.

The influence of leptospiras and their metabolites on the cellular wall results in the affection of the adrenal gland epithelium, all the cortical and subcortical layer of the kidney that results in the uropoiesis affection. There is a possibility of the development of renal insufficiency.

The fifth phase includes the formation of the sterile immunity. The tense humoral immunity is combined with the expressed local organic and cellular immunity. Then a stable recovery comes.

Anatomic pathology

Leptospirosis is characterized by the affection of the capillary endothelium of a various organs and tissues. The walls of the vessels are fragile, their permeability is increased, this is accompanied with numerous hemorrhages in the kidneys, liver, lungs, endocardium and pericardium, mucous membrane of the gastroenteral tract. The liver is enlarged, plethoric and with smooth surface.

The histological investigation shows an edema of the interstitial tissue, dystrophy of the hepatic cells without an expressed cytoptesis of hepatocytes, biliary thromboses in the central zone of the lobules.

The most considerable changes can be found in the kidneys. The kidneys are considerably enlarged, there are such typical symptoms as a stroma edema, numerous hemorrhages, a sharply expressed granular degeneration of the convoluted tubules epithelium up to necrosis. The kidney affection in leptospirosis can be considered as nephrosonephritis.

There are hemorrhages in the adrenal glands, sometimes considerable. The muscle affection is also characteristic of leptospirosis, especially the affection of

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musculus gastrocnemius and musculus thoracic. There are hemorrhages of various sizes; an uneven swelling of the fibers, degenerative changes in the synapses of the muscular fiber and nerve, sometimes coagulation necrosis which causes myalgia. Dystrophy and lipid dystrophy develops in the heart muscle, sometimes there is interstitial myocarditis. There are hemorrhages in the lungs as well as in other organs. There is often an edema of the meninx vasculosas.

Clinical manifestations

The course of leptospirosis can be mild, middle-moderate and severe. The severity of the course depends on the microbe virulence, the dose of infection, the reactivity of the microorganism.

The main criteria of the severity are follows: the degree of toxicity, the expressiveness of the affection of the liver, kidneys, central nervous system, heart, adrenal glands, hemorrhagic manifestations.

There are cycles in the leptospirosis course. There is and incubate period, the beginning, height and convalescence.

The incubate period lasts 2-20 days (more often 7-10 days). The disease has an acute onset. The patient can indicate not only to the date but even the hour of the disease onset. The fever usually has a remitting or constant character, it lasts 5-9 days then it falls down in the form of accelerated lysis. There can be another wave (a relapse).

From the first hours the patients complain of intense headaches, pain in the muscles, especially, musculus gastrocnemius, the muscles of the scalp, neck, back and abdomen. In 1888 W. P. Vasiliev wrote that there is no such an intensive myalgia in the musculus gastrocnemius in case of any other disease. The abdomen pain can be so intense that there is a suggestion about an acute surgical pathology.

The symptoms of toxicity increase. The patients are flaccid, adynamic. The patients has a characteristic appearance - the face is edemic, hyperemic, the vessels of the scleras are injected.

There is often herpetic rash on the lips. In some patients (in 30 % cases) a polymorphic symmetric rash which stays for several days appears on the third - fifth day of the disease.

In some cases there is an enlargement and painfulness of the peripheral lymph nodes. The liver gets enlarged early, on the second-third day of the disease. Jaundice develops in the moderate severe - course as well as in the severe course. The liver has a dense consistence, it is painful at palpation. In a half of the patients the spleen gets enlarged.

There are considerable changes in the cardiovascular system: dull heart sounds, sometime relative bradycardia, arrhythmia, extrasystole. In case of an expressed toxicity the arterial pressure sharply decreases (up to collapse) as a result of a decrease of the precapilary arteries.

The initial period of leptospirosis is characterized by the peculiar changes in the central nervous system, in some patients there are such symptoms as

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disorders of the consciousness and even unconsciousness, cramps besides an expressed persistent headache, insomnia, delirium. In 10-40 % cases there are meningeal symptoms: rigidity of the occipital muscles,Kernig's sign,Brudzinsky's sign that are distinctly manifested on the fifth-eighth day of the disease. In such patients the spinal puncture confirms the diagnosis of serous leptospirous meningitis - cerebrospinal fluid flows out under an increased pressure, it is transparent. The microscopia of the cerebrospinal fluid shows leptospiras, during the regular one outside the dark field of vision - moderate lymphocytic pleocytosis. The amount of protein is increased. Leptospirous meningitis usually has a nonmalignant character, it usually lasts 8-10 days.

• At the end of the first week, and sometimes earlier. Jaundice develops in some patients (12-20 %). The intensity of jaundice and its duration depends on the severity of the disease and can last several weeks (1-4). A moderate skin itching is quite possible. The urine is dark,the color of the excrements is not changed.

With the development of jaundice the condition of the patients usually worsens. The most severe manifestations of leptospirosis appear at the end of the first week - at the beginning of the second week of the disease.

The hemorrhagic syndrome appears on the seventh-tenth day: petechial eruption on skin, hemorrhages under the conjunctive, hemorrhages in the nose, gums, stomach, intestine, uterus. The hemorrhages can be repeated, massive and result in anemia. Many clinicians have observed that the expressiveness of the hemorrhagic syndrome corresponds the severity of leptospirosis and has a certain prognostic significance (Fig. 7). The degree of the kidneys affection is even more significant while evaluating the severity of leptospirosis, the kidneys are always affected to some degree in leptospirosis.

From the first days of the disease there can be oliguria, moderate proteinuria, in the urine there are fresh erythrocytes, leukocytes as well as hyaline casts and the cells of the renal epithelium. The symptom of the kidneys affection become the most expressed from the seventh-tenth day of the disease. Oliguria can be followed by anuria, an acute renal insufficiency may develop, m spite of the development of an acute renal insufficiency, there is usually no edema and arterial hypertonia in leptospirosis. Sometimes an acute renal insufficiency develops very early, on the fourth day of the disease. It is an acute renal insufficiency resulting in uremia that is a frequent cause of the lethal outcome of the disease. If the therapy is timely and adequate,the kidneys affection in leptospirosis can be cured. Oliguria is followed by polyuria, and function of the kidneys gets gradually normalized.

The second week corresponds to the height of the disease. At this time jaundice becomes the most intensive, the hemorrhagic and meningeal syndromes increase or appear for the first time. The changes in the cardiovascular system increase: the pulse is rapid and weak, a systolic murmur is sounded in the apex cordis, there can be extrasystolia. The electrocardiogram shows diffusive changes of the myocardium.

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At this period of the disease the infiltrates connected with the hemorrhagic foci are sometimes formed in lungs, this is accompanied by the sanguinolent sputum secretion.

By the end of the second week the condition of the patients improves. The headache and myalgia reduce, the jaundice intensity gradually decreases, a great amount of urine begins to excrete. The patients feel weak for a long period. The duration of the disease averages to 3-4 weeks. Some patients (20-60 %) may have relapses. In 5-7 days after the feverish period the temperature rises again, headaches and myalgia appear. The relapses and acute forms are not so severe as the first phase, as a rule. The temperature does not usually rises very high, the fever does not last more than 2-3 days. Some patients have 3-4 acute forms of relapses.

In leptospirosis the hemogram is characterized by the progressive anemia, a low reticulocytes number. In the patients with a hemorrhagic syndrome there is expressed thrombocytopenia, an increased period of the blood coagulability. Leukocytosis is a characteristic feature. The number of leukocytes increases up to 12-25 x Þ5 in 1 mkL. In the differential blood count there is neutrophilia with a shift to the left, expressed lymphopenia. The ESR reaches 40-60 mm/h.

The bilirubin amount in blood increases in case of the icteric form. The level of prothrombin may moderately decrease. The activity of transaminases is either normal or slightly increased on the tenth-fifteenth day of the disease.

The asthenovegetative syndrome is a characteristic feature of the convalescence period. Anemia and proteinuria remain for a long time.

Some patients have eye affections - uveitis, iritis, iridocyclitis that develop in 2 weeks and in several months after the onset of the disease. There can be other complications in the acute period - massive hemorrhages, an acute renal and hepatic insufficiency, uremia, myocarditis, an acute cardiovascular insufficiency.

Complications

The most common complications of leptospirosis, which are characteristic for its severe course are infectious-toxic shock, renal-hepatic failure, massive internal bleeding, DIC-syndrome, acute heart failure.

Diagnosis

It is quite difficult to diagnose leptospirosis,especially during the first days of the disease. The bacteriological method is of a little practical importance because leptospiras grow badly and slowly on the artificial media. The correctly taken epidemiological history plays the most important part in diagnosing leptospirosis. It is necessary to take into account the patient's occupation, his contact with agricultural animals, work in the meadows, swimming in the rivers and ponds, the existence of rodents in the surroundings. The epidemiological history not only determines the direction of diagnosis but gives an opportunity to control the environment. The following peculiarities of the clinical symptoms

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are taken into consideration: jaundice, accompanied by fever, myalgia, hematuria, hemorrhages. The diagnosis based on the clinical-epidemiological investigation, is confirmed by the laboratory data.

The materials used for diagnosing leptospirosis are blood, urine, cerebrospinal fluid.

The following methods of the laboratory diagnosis are used:

1. Bacteriological, bacterioscopic.

2. Serologic.

3. Biologic.

The bacteriologic investigation includes the primary microscopia of the initial material and its inoculation of media for acquiring the leptospira clean culture. The patient's blood serum, cerebrospinal fluid or urine are centrifuged. The fall out is investigated with microscope in a dark floor. Leptospiras are found as thin sinous mobile threads that look grayish-whitish on the dark background. That is necessary to note that the presence of leptospiras in blood is undoubtedly indicative of leptospirosis, but the negative result does not allow us to exclude the disease. The initial material inoculation of the water-serum medium consists of the native rabbit serum. The inoculation is incubated for 30 days at a temperature of 28-30 °Ñ, the inoculation is examined on the dark floor of the microscope every 5-7 days.

The serologic investigations are done in the dynamics of the disease including the convalescence period. The reaction of the microscopic agglutination and lysis, as well as the complement fixation reaction are used to find antibodies in the serum of the sick people.

The reaction of the microscopic agglutination and lysis are done by a drop method with various serums of the patient's blood and with those leptospira serotypes which can be found hi this area. The results of the reaction are taken into account with the help of a microscope with a dark floor. In the positive case there are phenomena of sticking together, the leptospira agglomeration in form of small "spiders" and different degrees of their lysis. The titer is considered to be diagnostic when the serum is diluted 1:50-1:100.

The specific antibodies are discovered in the patient's serum at the end of the first - the beginning of the second week of the disease. The antibodies can remain in patients for several years, that is why the investigation of the twin serums are of a great diagnostic importance.

Leptospiras appear in liquor later than in the blood, that is why its investigation (microscopia and inoculation of the same media as the blood) are done when there are symptoms of meningitis. Urine can be investigated from the first day to 3 months from the disease onset.

The guinea-pigs that are very sensitive to L. icterochaemorrahaigae are used as a model for the biological test. The animals are infected by injecting the infected material (blood, urine, cerebrospinal fluid taken sterile from the sick

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person) intraperitoneally, intracutaneously, intravenously, through the scarified skm and mucous membranes. The material is taken at the time when the bacteriological and bacterioscopic investigations are done. The animals die if there are leptospiras in the initial material.

Differential diagnosis

However, in some cases there are diagnostic difficulties because of the polymorphism of the clinical picture, separate symptoms of which make it difficult to diagnose a disease (jaundice, fever, abdomen pain, myalgia, meningeal syndrome).

First of all it is required to differentiate the disease from flue,typhoid fever, hemorrhagic fever with a renal syndrome (HFRS), virus hepatitis, meningitis.

In case of flue the headache has a distinct location (in the superciliary arch area), there is no hepatosplenomegaly, jaundice. There are expressed catarrhal symptoms. The hemogram shows leukopenia, neutropenia, the ESR is usually normal. The fever last from 2-3 to 5 days.

If there are such symptoms as an acute onset of the disease, a high temperature, intense headaches, the appearance of the patients, the liver and spleen enlargement, it is necessary to differentiate leptospirosis from typhoid fever. However, the following symptoms are characteristic of the initial period of typhoid fever: Kiari-Avtsin's sign, Govorov-Godelie's sign, Rozenberg's sign, and early increase of the spleen. There appears massive roseole-petechial eruption on the side surfaces of the breast, abdomen, extension surface of the extremities.

In HFRS there are no pains in the musculus gastrocnemius, there are such characteristic symptoms as loin pains, Pasternatsky's positive sign, petechial eruption located in the area of the shoulders and armpits. There is prolonged hypoisosthenuria, and in the urine fall out there are waxy casts, degenerative cells of the renal epithelium besides erythrocytes, hyaline casts. There is no jaundice and meningeal syndrome. The hemogram shows leukopenia at the increased ESR at the onset of the disease.

Virus hepatitis has a gradual onset, without chills, the temperature rises at the pre-icteric period. Muscle pains, scleritis, conjunctivitis are not characteristic of it. There are no meningeal and renal syndromes. The activity of transaminases is considerably increased. The hemogram shows leukopenia, low ESR.

If it is necessary to differentiate leptospirous meningitis form serous meningitis of another etiology, it is necessary to take into account the epidemiological history, pain in the musclus gastrocnemius; the development of the meningeal syndrome in 4-6 days after the disease onset, the simultaneous affection of the liver, kidneys; hemorrhagic syndrome.

Treatment

The most effective etiotropic agent is combination of antibiotics and antileptospirosis immunoglobulin if they are indicated in an initial stage when leptospires are in blood. Benzylpenicillin, tetracyclic erythromicin and streptomycin

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are indicated more often. The daily dose of benzylpenicillin can be changed from 3 to 12 millions units, however, the dose 6-8 millions units is more often indicated per day (in a muscle). It dosage depends on gravity of the disease course. The maximal dose of a preparation is indicated at development of meningitis. Ampicillin, oxacillin, ampiox are effective semisynthetic penicillins. Benzylpenicillin or semisyntetic analogue can be combined with streptomycin, tetracyclin is indicated 0.2-0.3 gm 4 times per day, it less often, than penicillins, causes reaction such as Yarish-Gersgeimer, however strengthens a permeability of vascular wall and promotes development of a hemorrhagic syndrome. It is contrindicated at the icteric form of leptospirosis fever and development of renal failure. Treatment with antibiotics is carried out during all feverish period and 2-3 days of normal temperature. In case of occurrence of relapse a new course of an antibiotic therapy must be indicated.

Clinical observations of last years has testified the inefficiency heterogeneous antileptospirosis immunoglobulin, oppression of immune system by it. The allogenic donor immunoglobulin which is effective in the first 3-5 days of disease are applied in medical practice, has no side-effects. The preparation prevents development of acute renal failure.

With the purpose of desintoxication and improvements of microcirculation in a vein there are infused solution of glucose, reopolyglucin, rheogluman, threesaultl, quartasault, and ascorbic acid. Good desintoxication effect is produced by the preparations that neutralize ammonia: rnithine, ornicetil, glutargin. At severe intoxication prednisolon and its analogues are indicated. The initial dose of prednisolon is 60-120 mg and more, it is used for short course,quickly reducing dose in process of clinical improvement. Enterosorbtion with using of granulated coal SKN, sillard P, enterosgel, polyphepan can be effective. At the icteric form there should be prescribed diets ¹ 5, 5A, and at pathology of kidneys - a diet ¹ 7.

At the development of the disseminated intravascular coagulation (DIC) carry out a complex of medical actions according to hematological research. At I stage (hypercoagulation) infuse in a vein heparin 2,500 units 4 times per day, reopolyglycin, dipiridamol (curantyl), pentoxyfilin (trental) contricali in bottles, ascorbic acid 5 % solution in ampoules 1 mL: 5-10 mL 2 times per day. At II stages heparin can be infused under the control of blood clotting time, other preparations (reopolyglycin, curantyl, trental) - in the same doses, as at I stage of syndrome. At HI stage of DIC infusing of heparin is not indicated. At hypocoagulation there is indicated native plasma or cryoprecipitat of plasma, trombocite mass. At hypofibrinolisis there are given acid aminocapronic, contrical, gordox, at secondary hyperfibrinolysis - synthetic antifibrinolitics, inhibitors of proteases - streptokinase, fibrinolysin are indicated.

At the bleeding with a tamponade cold, and infuse calcii chloridum, vicasol, aminocapronic acid are used. Infusions of a blood plasma, a red cells mass, albumin are indicated at bleeding. If hepatonephric insufficiency develops simultaneously plasma transfusion of blood with infusion of erythrocytar and

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trombocytar mass 2-3 times, and are used instead of albuminous preparations, a mixture of amino acids, for example alveosin-neo is recommended.

In occurrence of acute renal insufficiency (oliguria, hypoisosthenuria) there should be repeated lavages of stomach and an intestine 2-4 % solution of sodium hydrocarbonate, intravenous infusion of 40 % of glucose solution, euphyllin, mannit. At later infuse furosemid (lasix). At development of metabolic acidosis indicate natrii hydrocarbonas and Tris-buffer. If medicamental therapy is not effective and oliguria stage lasts more than 3-4 days, there is a necessity in plasmaferesis or plasmasorbtion or extracorporal dialysis by means of artificial kidney.

Prophylaxis

The deratization and sanitation veterinary measures are the essential part of the prevention. Deratization is for decreasing of the activity of the natural foci (wild rodents control) and the sanitation of the anthropurgias foci (the sinanthropos rodents control).

One of the directions of leptospirosis prevention is the actions which break the transmission of the disease by water in the natural foci (mechanization of agricultural work, the supplying of workers with water-proof clothes, a ban to swim in the infected reservoirs and to use unboiled water). Vaccination is recommended for the people who permanently stay in the natural foci. The people who belong to a group of high risk infection (cattle-breeders, veterinary doctors, the meat packing plant personal, night-men, deratizators) should be vaccinated with inactivated vaccine.

Control questions:

1. Definition of leptospirosis.

2. Mechanism of leptospirosis contamination.

3. Who can more likely get ill with leptospirosis?

4. What organs are damaged during leptospirosis infection?

5. Clinical manifestations and data of objective and laboratory examinationin in initial period, height of illness and in the period of reconvalestation.

6. Differential diagnosis of leptospirosis with influenza, viral hepatitis, rash and abdominal • typhus, sepsis.

7. Complications of leptospirosis.

8. Principles of medical treatment of leptospirosis.

9. Leptospirosis prevention.

6.

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Date: 2014-12-21; view: 1797