| What is the morphology of the plague causative agent?
| It is gram-negative small ovoid sticks, with bipolar staining, has a capsule, does not form spores, does not have cilia.
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| What are the virulent factors of the plague causative agent?
| Toxins (mice’s, hemolytic), VW-antigens, enzymes.
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| What is the natural reservoir of the plague infection?
| Rodents and hares.
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| What is the carrier of the plague causative agent?
| It is a flea.
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| What is the source of infection?
| Rodents and sick people.
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| What are the ways of spread the infection?
| They are communicative, transmissible, alimentary, airborne.
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| What is the patogenesis of the plague?
| When a flea feeds on a rodent infected with Y. pestis, the ingested organisms multiply in the gut of the flea and, helped by the coagulase, block its proventriculus so that no food can pass through. Subsequently, the "blocked" and hungry flea bites ferociously and the aspirated blood, contaminated with Y. pestis from the flea, is regurgitated into the bite wound. The inoculated organisms may be phagocytosed by polymorphonuclear cells and monocytes. The Y. pestis organisms are killed by the polymorphonuclear cells but multiply in the monocytes; because the bacteria are multiplying at 37 °C, they produce antiphagocytic proteins and subsequently are able to resist phagocytosis. The pathogens rapidly reach the lymphatics and an intense hemorrhagic inflammation develops in the enlarged lymph nodes, which may undergo necrosis and become fluctuant. While the invasion may stop there, Y. pestis organisms often reach the bloodstream and become widely disseminated. Hemorrhagic and necrotic lesions may develop in all organs; meningitis, pneumonia, and serosan-guineous pleuropericarditis are prominent features.
Primary pneumonic plague results from inhalation of infective droplets (usually from a coughing patient), with hemorrhagic consolidation, sepsis, and death.
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| What are the typical clinical manifestations of the plague?
| The presence of plague bubo.
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| What is the active specific prevention of the plague?
| It is using the live vaccine for parenteral and oral input.
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| What is the passive prevention?
| Specific immunoglobulin is used for the passive prevention.
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| What is the morphology of tularemia causative agent?
| Small polymorphic gram-negative bacillus, motionless, covered with slimy substance (capsules).
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| What are the tularemia antigens?
| Antigens causing tularemia are the envelope Vi-antigen, somatic O-antigen.
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| What are the main pathogenic factors of the tularemia causative agent?
| They are the endotoxin, Vi-antigen substances that suppress phagocytosis.
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| What is the natural reservoir of the tularemia infection?
| Rodents, hares, water rats.
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| What is the patogenesis of the tularemia?
| F. tularensis is highly infectious. Penetration of the skin or mucous membranes or inhalation of 50 organisms can result in infection. Most commonly, organisms enter through skin abrasions. In 2-6 days, an inflammatory, ulcerating papule develops. Regional lymph nodes enlarge and may become necrotic, sometimes draining for weeks. Inhalation of an infective aerosol results in peribronchial inflammation and localized pneumonitis. Oculoglandular tularemia can develop when an infected finger or droplet touches the conjunctiva. Yellowish granulomatous lesions on the lids may be accompanied by preauricular adenopathy. In all cases there is fever, malaise, headache, and pain in the involved region and regional lymph nodes.
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| What are the ways of spread the infection with tularemia?
| Contact, transmissibility, alimentary, airborne.
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| What are the methods of the tularemia diagnostics?
| Allergic, serological, biological, rapid diagnostics.
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| What are the features of the tularemia pure culture isolation?
| At first the material for research is inoculated in the mice, after that it is inoculated on selective medium.
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| What is the method of early diagnosis of the tularemia?
| It is allergic test.
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| What is specific prevention of the tularemia?
| It is using live tularemia vaccine.
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