Tularemia

  • Pathogenesis and pathological anatomy
  • The clinical picture
  • Diagnosis, treatment and prevention of tularemia
  • Tularemia is a natural focal acute infectious disease proceeding with fever, septicemia and characteristic lymph nodes.
    Etiology. Exciter (Bact. tularense) - aerobe, size 0,2 - 0,7 MK, has the form of small kocka, still, the dispute does not form, gram-negative, allocates endotoxin. Bacteria can be kept for long in the external environment, for example in water at temperature 1 degree - up to 9 months. without a decrease in virulence, with increasing f to 20 - 25 degrees bacteria die off in the water for 1-2 months; to the low temperatures, insensitive survive at temperature-30o. Heating up to temperature 60 degrees kills bacteria in 20 minutes, boiling, immediately. Resistant to drying up to 1.5 months. In salted meat viable up to a month. Conventional disinfectants [1-3% Lysol, solution dichloride mercury (mercuric chloride) 1 : 1000, 1% soap-cresolves solution, 5% alcohol] and ultraviolet rays quickly kill the pathogen. Chloride lime in the dose of 1-2 mg per 1 l of water at temperature 12-16° kills germs in contaminated water.
    Epidemiology. Reservoir and source of tularemia in nature are rodents, especially the common vole, water rats, house mice, partly muskrat, hamsters, and rabbits. Ways of infection tularemia: contact - contact with sick animals and their excretions, and contaminated objects (hay, straw, grain), as well as when swimming; suction - inhalation of dust at threshing stale cereal, zastrahovany hay and straw, contaminated secretions rodents, insulating dugouts and trenches; alimentary - drinking water sources contaminated by secretions or corpses patients rodents, eating poorly treated meat of sick animals (hares, rabbits); vector-borne - through the bite of fleas rodents (mites and other) and flying insects (mosquitoes, horseflies).
    There are following outbreak of tularemia. 1. Commercial - occur in spring in the hunt for water rat among hunters and fishers. Infection occurs through contact with the carcass during the removal and processing of skins. Clinically dominated by the bubonic form of tularemia localization of Bubnov in the upper extremities. 2. Agricultural - are recorded in the late autumn and winter. The delay in harvesting, belated threshing grain lead to increased multiplication of rodents on weedy fields, in haystacks and shock neobmenennogo bread, the hay and straw. At mass congestion of rodents tularemia almost always gives rampant epidemic with the death of up to 80% of mice. The pathogen of secretions and body of a rodent in the water, food, fodder, grain, potato and others, as well as inhalation of dust at threshing inhabited by rodents loaves contribute to the spread of cardiovascular and pulmonary forms of tularemia. 3. Water occur when drinking water from a contaminated source. Prevail and abdominal angina-bubonic form of tularemia. 4. Food is usually shorter than water. Arise when eating foods contaminated with infective secretions of patients rodents. Different appearance Angin, the prevalence of cervical, parotid and submandibular of Bubnov, and abdominal and generalized. 5. Vector-borne occur by the bite of bloodsucking arthropods (mosquitoes, gadflies, ticks, and other). At the bite location vector appears sore, then bubo in regional lymph node (ulcerative-bubonic form).
    From a sick person to a healthy tularemia is not transmitted. Recover acquires a strong immunity.