What is Sap?
Sap is an acute infectious disease characterized by a septic course and the formation on the skin and mucous membranes of pustules, ulcers, multiple abscesses in the internal organs.
Causes of Sapa
The causative agent of glanders, Pseuclomonas mallei, is a Gram-negative bacillus 2–4 µm long, 0.5–1 µm wide, with rounded or slightly pointed ends. The spore does not form capsules, does not have flagella, grows well on ordinary nutrient media. In the external environment (water, soil) lasts 1 – 1.5 months. Dies when heated and exposed to various disinfectants. The pathogen is sensitive (in vitro) to streptomycin, antibiotics of the tetracycline group and some sulfanilamides (norsulfazole).
The source of infection are some domestic animals (horse, mule, donkey, camel), especially those with acute form of glanders. Currently found in some countries in Asia, Africa and South America. In our country, glanders have not been found for many years. Diseases among people are rare. Infection occurs when the pathogen enters the damaged skin, mucous membrane of the respiratory and digestive tract. In the laboratory, airborne infection is possible.
Pathogenesis during Sapa
Gates of infection – damaged skin or mucous membranes. On the site of the introduction of the pathogen may occur sapnye nodules – granulomas, then subject to decay. The pathogen enters the regional lymph nodes, where the inflammatory process develops with purulent disintegration. Then the pathogen is spread by hematogenous throughout the body and causes the occurrence of secondary septic foci in the muscles and internal organs. These foci may be opened. Often affects the lungs with the formation of pneumosclerosis, abscesses, bronchiectasis. Purulent meningitis and brain abscesses may develop.
The incubation period often lasts 1-5 days. The disease begins acutely with chills and fever, headache, fatigue, arthralgia and myalgia. At the site of penetration of the pathogen, a dark red papule is formed, which quickly turns into a pustule and then ulcerates. Later, after generalization of the infection, multiple pustules appear, most of which turn into ulcers. Sapny ulcer is crater-shaped with a characteristic sebaceous bottom and is surrounded by a nimbus of sapnye nodules that are necrotic. Especially often affects the skin of the face. Serious nasal discharge is observed. In the future, the process captures the internal organs, often the lungs, as well as muscles, cartilage, bone. Abscesses and deep infiltrates are formed with their subsequent purulent fusion. The general condition of patients is deteriorating dramatically, fever has a hectic character. Blood pressure drops, heart sounds become deaf, bloody mucus appears. X-ray and clinically detected small focal or confluent pneumonia.
Chronic glanders develops gradually, proceeds in the form of exacerbations and remissions. The main clinical symptoms are general intoxication, fever of the wrong type, multiple pustules, prone to ulceration, abscesses in the muscles with the formation of characteristic fistulas, confluent pneumonia with multiple asbestosis. Cachexia and total amyloidosis may develop.
Diagnosis of Sapa
Recognition is based on the epidemiological prerequisites (contact with sick animals) and the characteristic clinical picture. Sap is differentiated from sepsis, lung abscess, melioidosis, pulmonary tuberculosis and pulmonary forms of mycoses (aspergillosis, nocardiosis, histoplasmosis, etc.).
From laboratory methods in the diagnosis using isolation of the pathogen and serological reactions (RAC, agglutination, RPGA). To isolate pathogens, purulent discharge of ulcers, punctate abscesses, nasal discharge are taken. An additional method is the allergy test with mallein. Mallein is injected intradermally with 0.1 ml at a dilution of 1: 100. The test becomes positive with the 2-3rd week of illness.
Sulfathiazole is prescribed for 5-6 g / day for 25-30 days in combination with fortifying agents (vitamins, oxygen therapy, blood transfusion). When abscesses are formed, surgical drainage is performed. When layering a secondary infection, antibiotics are prescribed. Promising is the combination of sulfonamides with vaccine therapy. To do this, use mallein in increasing doses (under the skin or intracutaneously).
The prognosis of untreated acute glanders is always unfavorable. With chronic sape lethality reached 50%. Modern methods of treatment, especially with early initiation of therapy, make the prognosis more favorable.
Sanitary-veterinary measures are being carried out (identifying and destroying patients with the acute form of animal glanders, monitoring positive responses to mallein). Sick people are subject to isolation and hospitalization in infectious hospitals that are adapted to work with especially dangerous infections. Infected, but not yet sick, people are given emergency prophylaxis with sulfatiosol (at the rate of 0.1 g / (kg-day) for 5 days). In the laboratories they work with the observance of all rules for working with especially dangerous pathogens (eye and respiratory protection, rubber gloves). In an accident, all persons who were in the room are subject to observation for 21 days. Specific prevention is not developed.