MIIM20002 Lecture Notes - Lecture 31: Dengue Virus, Togaviridae, Bunyavirales
4 Aug 2018
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Document Summary
Transmitted by means of an infected blood sucking arthropod. Vertebrate hosts can act as reservoirs (e. g. pigs and japanese encephalitis virus) Humans are usually incident hosts; exceptions include yellow fever and dengue. Most arbovirises belong to the togaviridae (alphaviurses), reoviridae, flaviviridae, Flavivirus phylogeny based on the gene sequence of ns5. Den-1, den-2, 3 and 4 are dengue virus. They are actually very distantly related - 4 different viruses. Many infections in susceptible hosts are clinically silent. Ab won"t be able to neutralise another virus though. Infection with one type confers life-long immunity to that type. A second infection with a different denv type (serotype) is associated with enhanced risk for severe disease. No animal models of disease, no licensed vaccines or anti-viral drugs. Most denv (99. 99%) circulating in urban environment between people via mosquito. Sylvatic cycle: transmission in forest between non-human primates. Not common to have disease in older ppl as they would be immune by then.
