Leptospirosis - Causes, Symptoms and Treatment .MF .
Leptospirosis (Weil's disease-Vasileva, water fever, nanukayami Japanese daily fever) - an acute zoonotic natural focal bacterial disease with multiple mechanisms of transmission, characterized by lesions of the vascular endothelium, liver, kidney and central nervous system against the background of intoxication syndrome.
Long before the discovery of the causative agent of leptospirosis, Weil German scientist described the symptoms of the four cases of icteric disease, and only after a quarter century, he was discovered pathogen - Japanese scientists, he was isolated from the liver of a deceased person.
causative agent of leptospirosis
Leptospira icterohaemorrhagiae - bacteria in the form of a tightly-twisted spring, giving the appearance of pearls strands by microscopy and pale pink color method Romanovsky-Giemsa.Only about 200 serovars (Leptospira species).The pathogen has factors of pathogenesis, causing the characteristics of the disease:
• presence of flagella, which are due to Leptospira a
• obtain energy by oxidation of fatty acids - the only source;
• explains the presence of endotoxin damage the vascular endothelium (followed by exudation from the blood vessels) and the general intoxication;Enzymes
• pathogenicity: hemolysin, fibrinolizin, plazmokoagulazu, lipase - they cause destructive changes in parenchymal organs;
Leptospires stable in the environment and stored in open water up to 30 days or more in a wet soil - up to 270 days on food products - up to several days (especially at low temperature).Dying on drying, the direct effect of UVB, boiled, treated with disinfectant.Sensitive pathogen to the following antibiotics: tetracycline, penicillin, streptomycin, rifampicin.
susceptibility among people much, ill mostly elderly, newborns, people with CID (immunodeficiency) - ie that category that have some disorders of the immune system.Man does not have the specific resistance to pathogenic Leptospira, but the sensitivity to different types are not the same.With regard to prevalence, it is not ubiquitous, leptospirosis is a natural focal infections occurring in the North Caucasus, in the Crimea, in the central regions of the European part of Russia, Siberia and the Far East.Outbreaks are usually located in the forest area, in floodplains and wetlands - the causative agent unnecessarily hydrophilic (well developed with high humidity).For leptospirosis characterized by the summer-autumn season and the peak incidence occurs in August.
reasons leptospirosis infection
source - the sick and ill animals.Carriers - ticks, fleas.Carriers - rodents.Ways of infection:
• nutritional - in meat and other products from infected animals through infected plant food waste products of infected animals;
• pin (by direct contact with sick animals) and contact-household (by contact with infected household items);
• aerogenic - inhalation of air contamination;
• transmissible - the bite of infected persons mites or fleas.Symptoms of leptospirosis
incubation period, or the first phase (the time interval from the moment of introduction of the pathogen to the first clinical manifestations) lasts between 7-20 days, but on average - 10. At this time, leptospira, falling on the mucous membrane (any field) orskin containing microdamages, begin to multiply and spread through the blood (hematogenous pathway) reaching various organs, but most often affecting liver / kidney / CNS / vascular endothelium.Once the pathogen concentration reaches a certain level, the next period - clinical manifestations.
period of clinical manifestations lasts up to 4 weeks, and during this period include - generalization, and the height of the residual effects.Disease begins acutely, with obscheintoksikatsionnyh manifestations - fever and a temperature rise to high numbers (lasting 4-5 days), myalgia (especially in the calf muscles due to focal necrotic and necrobiotic changes) and lasts about 7-10 days.Then comes the second phase - the height, which lasted about 2 weeks, which is the result of secondary bacteremia, and then a secondary lesion of the internal organs and is characterized toksinemiey (third phase) due to the gradual destruction of Leptospira and recovering from their loss of endotoxin with the subsequent development of ITSH(toxic shock syndrome) and multiple organ failure, and in parallel there is systemic failure of the vascular endothelium, there hemorrhage (bruises) on the skin, mucous membranes and internal organs.
also develop jaundice - both because of the hemolysis, and because of the destructive changes as a result of developing liver failure.Because vascular lesions in the kidneys, renal failure develops.After damage to the liver and kidney are rapidly developing coma, because they fail to fulfill one of its supporting function - detoxification (excretion of toxic products of metabolism).An objective study - "hood symptom", which is represented by redness and puffiness of face, redness of the skin of the neck and upper chest.Celebrating injection and ikterichnost (yellowness) sclera vessels, with no signs of conjunctivitis.
With the spread of Leptospira on the body, there is distributed through the blood-brain barrier, reaching the central nervous system, there are serous or purulent meningitis or meningoencephalitis - positive are meningeal signs (neck stiffness, symptoms Keringa and Brudzinskogo)
above listed symptoms (hemorrhage, renal and liver failure, ITSH) - a collective image, hiding the following:
• hemorrhage - bleeding in the skin, mucous membranes and, in severe cases, the internal organs.Rash has some features:
- skin rashes resemble those kind of measles / rubella / skaralatinopodobnoy rash;
- localization on the chest, stomach and arms;
- decompensation, there are nasal, abdominal (intraorganic) bleeding at the injection site - bleeding
- the rash may disappear after a few hours, leaving a peeling and / or pigmentation
Hemorrhage with leptospirosis
•Renal failure - characterized by a first reduction (oliguria), and then the lack of urination (anuria), as well as positive symptoms of liver develops uremia and violation of electrolyte concentration in the blood that contributes to toxicity.
• liver failure - will manifest jaundice and itching of the skin, sclera ikterichnost, possible pain in the right iliac region.But there is also a yellowness due to direct hemolysin (pathogenicity enzyme) - it destroys the red blood cells, releasing bilirubin.
• ITSH develops as a result of direct action exotoxin Leptospira, and under the influence of endotoxin released during their death.Violation of detoxification of the liver and the kidneys leads to a violation of the elimination of toxic metabolic products.Also, the contribution to ITSH make products of decomposition of necrotic tissue formed as a result of destructive changes.
diagnosis of leptospirosis
At diagnosis, are weighty symptoms: fever, trombogemorragichesky syndrome, appearance, myalgia, jaundice, kidney damage.It is important to conduct a thorough diagnosis for differntsialnuyu leading features:
- fever lasted for about 5 days (typhoid / paratyphoid fever, infectious mononucleosis, adenovirus, tifopodobnaya form of salmonellosis, etc. - the list is very extensive, includes about 19 diseases)
- by jaundice (viral and toxic hepatitis, the diseases that in fever, sepsis and malaria)
- on trombogemorragicheskih syndrome (hemorrhagic fever, septicemia, typhus)
Diagnosis is based not only on clinical data, but also on epidemiological indications - the place of work(farm worker, a hunter, a veterinarian, deratizator), as well as contact with wild and domestic animals, paying attention to swimming in open water (due to the high risk of water contamination).
On palpation the liver is determined hepatomegaly (or hepatosplenomegaly) - the liver is enlarged and protrudes from under the edge of the costal arch at 2-3 cm, it is painful palpation, the patient also points to the subjective feelings of dull aching spilled pain in the right upper quadrant (charactershingles and the pain is possible with irradiation).
specific and nonspecific laboratory diagnostics
specific diagnosis - use of bacteriological, microscopy, biological and serological studies.From the first days of the disease (which is after the beginning of symptoms), using dark-field microscopy can detect leptospira in the blood, and later in the urine, and CSF (cerebrospinal fluid - it is taken only for positive meningeal signs).But the drawback of this method is that it gives results after 8 days - so much time growing Leptospira, although it is one of the most reliable methods.
biological method is carried out by infecting laboratory animals - it is outdated and has lost its significance.
serological method implies the use of a PMA (reaction microagglutination) - recommended by the WHO, it is to identify antigens and antibodies that have an affinity with one another and thus forming agglomerates.Positive consider an increase in antibody titer of 1: 100 or more, but antibodies appear not earlier than 8 days from the onset of the disease.
genetic method - the use of PCR (polymerase chain reaction) is directed to the detection of Leptospira DNA in biological materials from a patient.
nonspecific laboratory diagnostics: OAK (leukocytosis, ↑ ESR, ↑ bilirubin both fractions, residual nitrogen, ↑ ALT and AST, ↑ ALP), OAM (reduced amount, ↑ / ↓ protein, ↑ bilirubin, ↑ urobilinogen, ↑ ketone bodiesetc).
Treatment of leptospirosis
treatment is carried out only under strict bed rest in the hospital environment, including etiotropic, pathogenetic and symptomatic therapy.Causal therapy - appointment of sensitive antibiotics:
• Ted penicillin 150-200 / kg / day - if this group of antibiotics have allergies, it can be replaced by a suitable formulation of the macrolide group, because of their chemical forms are similar;
• any drug of amino, tetracyclines and cephalosporins in age dosages for about two weeks, complete reception of antibiotics after 3 days from the normalization of temperature.
• Gamma globulin from ox hyperimmune serum.Pathogenetic treatment is aimed at the prevention or elimination of the following conditions by infusion therapy, hemodialysis: acute renal failure (additional liquid volume and the implementation of forced diuresis using diuretics), acute cardiovascular failure (cardiac glycosides, ascorbic acid, vitamins B1 and B6, etc.e) A, cerebral edema (autonomic blockade, the establishment of adequate diuresis, cerebral metabolites - peratsetam, aktovegin, etc.), the development of DIC (GCS, protease inhibitors, detoxification therapy, etc. - extensive treatment of this condition, and is carried out inconditions resuscitation).
been ill are subject to clinical examination at 6 months - you need an eye doctor examination, a neurologist and pediatrician / physician, and over the next months - monthly visits to a pediatrician / physician with the assistance of specialists in the profile of clinical manifestations.The first two months - the implementation of the clinical and laboratory examinations and, with negative results, the examinee can be removed from the register.But persistent positive results, the observation is carried out within 2 years.
development ITSH, DIC, hemorrhage and vnturipolostnyh bleeding, meningitis, encephalitis, polyneuritis, the occurrence of secondary bacterial complications, etc.
Prevention of leptospirosis
Nonspecific prevention is carried out jointly by the Federal Service and Veterinary Service by identifying and treating sick animals, a regular disinfestation populated areas, protection of water bodies from pollution sick animals and water disinfection.
Question: Harmful if sick leptospirosis people to others?
answer is no, because it is a biological dead end in the spread of infection, although the risk remains, even if minimal.
Question: Does immunity persists after suffering a disease?
Answer: Yes, quite a long (perhaps lifetime), but strictly type-specific.Ie, if the infection happens in any other serovar Leptospira, it is possible to re-infection.
therapists Shabanova IE