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The dengue — the acute arbovirusny illness of tropical countries which is characterized by two-wave fever, arthralgias and mialgiya, a dieback, a polyadenitis, a leukopenia and quite often hemorrhagic syndrome. Fever of the dengue, is transmitted by mosquitoes. It is widespread in tropics and subtropics, especially in the countries of southwest part of the Pacific Ocean. Severe forms of fever of the dengue were registered in the cities of Southeast Asia. Visitors get sick seldom.
Etiology. The activator of the dengue — RNA-viruliferous. 6 serotypes are known. The virus termolabilen, is sensitive to disinfectants, in blood serum of the person at — 70 °C and in the dried-up look remain till 8 — 10. The strains adapted to mice, nepatogenna for the person.
Epidemiology. An infection source — the sick person and monkeys at whom the infection can proceed latentno. The patient is infectious in the period of a virusemia. The activator is transferred by mosquitoes which become infectious in 8 — 14 days and keep the infecting ability for life. In a body of a mosquito the virus develops at air temperature not below 22 °C. It causes distribution of an illness in tropical countries between 42 ° northern and 40 ° southern latitude. In the CIS does not meet.
Pathogeny. The activator gets into an organism at a sting the infected mosquito. On site a sting in cells of reticulohistocytosis system there is a reproduction and accumulation of a virus. The virusemia lasts from the last hours incubations to 3 — the 5th day of the feverish period. With blood the virus is brought in a liver, kidneys, muscles, a brain, connecting fabric etc. The cells affected with a virus are exposed to a cytolysis with a repeated exit of a virus in blood. At primary infection of the dengue it is shown only in a classical form, the hemorrhagic option of an illness results from repeated infection.
Clinic. The illness proceeds in two forms: classical fever of the dengue and hemorrhagic fever of the dengue. The incubation interval lasts 3-15 days (more often 5 — 8). The disease begins sharply with a fever, rise in temperature to 39 — 41 °C. From the 1st day the algichesky syndrome, especially severe retroorbital headache, and also muscle and joints pain is expressed (gait without bending legs — "dandy", "dandy"). Swelling and reddening of small joints is possible, there are nausea and vomiting. The hyperemia and puffiness of the person, an injection of vessels of scleras, the general erythema ("red fever") and a skin hyperesthesia are clear. Peripheral lymph nodes increase. Tachycardia, and with 2 — the 3rd day of an illness — bradycardia is noted. In blood the leukopenia, thrombocytopenia are found.
Internals are significantly not changed. To 3 — to the 4th day temperature decreases that is followed pouring then. The state improves, but mialgiya, arthralgias remain, typical gait, sharp weakness ("a lead cape on shoulders"), In 1 — 4 day increases temperature again, the main symptoms of an illness amplify. The second wave proceeds easier and 2 — 3 days last. 80 — 90% of patients during the second wave or right after temperature drop have plentiful makulo-papular ("flying measles"), urtikarny or scarlatiniform ("rheumatic scarlet fever") a rash which is followed by an itch and leaving a scaly peeling. The general duration of an illness is 6 — 10 days. Reconvalescence drags on for 3 — 8 weeks (astenisation, a joint pain and muscles).
The hemorrhagic form proceeds more hard. Except the described clinic during the first feverish wave sharper intoxication is observed. At most of patients the liver sizes increase. From the 2nd day of an illness in different degree the hemorrhagic syndrome is expressed: petekhialny rash, hemorrhagic purpura, extensive ecchymomas, bleeding of gums, nasal, pulmonary, gastrointestinal bleedings. At 20 — 40% of patients infectious and toxic shock with symptoms of oppression of the central nervous system, cardiovascular insufficiency, a pachemia, a hypoproteinemia, oligo-or anuries develops. The lethality at classical fever of the dengue does not exceed 0,1 — 0,5%, at hemorrhagic — reaches 5%, and among children — 15 — 20%.