传染病学英文版课件：DENGUE DENGUE HEMORRHAGIC FEVER.ppt

DENGUE DENGUE HEMORRHAGIC FEVER EpidemiologyIn India first outbreak of dengue was recorded in 1812A double peak hemorrhagic fever epidemic occurred in India for the first time in Calcutta between July 1963 March 1964In New Delhi, outbreaks of dengue fever reported in 1967,1970,1982, 1996 BURDEN OF DISEASE IN S.E.ASIACATEGORY-A (INDONESIA,MYANMAR,AND THAILAND)CATEGORY-B (INDIA,BANGALADESH,MALDIVES,AND SRILANKA)CATEGORY-C (BHUTAN, NEPAL)CTEGORY-D (DPR KOREA) Dengue VirusCauses dengue and dengue hemorrhagic fever It is an arbovirus Transmitted by mosquitoes Composed of single-stranded RNA Has 4 serotypes (DEN-1, 2, 3, 4) Dengue VirusEach serotype provides specific lifetime immunity, and short-term cross-immunity All serotypes can cause severe and fatal disease Genetic variation within serotypes Some genetic variants within each serotype appear to be more virulent or have greater epidemic potential The most common epidemic vector of dengue in the world is the Aedes aegypti mosquito. It can be identified by the white bands or scale patterns on its legs and thorax. Aedes aegyptiDengue transmitted by infected female mosquito Primarily a daytime feeder Lives around human habitation Lays eggs and produces larvae preferentially in artificial containers Clinical Characteristics of Dengue FeverFever Headache Muscle and joint pain Nausea/vomiting Rash Hemorrhagic manifestations Patients may also report other symptoms, such as itching and aberrations in the sense of taste, particularly a metallic taste. In addition, there have been reports of severe depression after the acute phase of the illness. 1.The virus is inoculated into humans with the mosquito saliva. 2.The virus localizes and replicates in various target organs, for example, local lymph nodes and the liver. 3.The virus is then released from these tissues and spreads through the blood to infect white blood cells and other lymphatic tissues. 4.The virus is then released from these tissues and circulates in the blo