Middle East DVEP - Armed Forces Pest Management Board

human morbidity in areas of northern Europe and South Africa, this disease is expectedto have minor impact on military operations in the Middle East.Disease Distribution. Sindbis virus is one of the most widely distributed of all knownarboviruses. Studies have demonstrated Sindbis virus transmission in most of the EasternHemisphere. Serological surveys and viral isolations indicate that Sindbis virus iscirculating in many parts of the Middle East.Transmission Cycle(s). A wide range of wild and domestic vertebrate species aresusceptible to infection with Sindbis virus. Most experimentally infected wild birdspecies easily produce viremias high enough to infect several different species ofmosquitoes. Wild and domestic birds are considered the main enzootic reservoir.Although several species of domestic animals can become infected with Sindbis virus,there is no evidence that these infections result in significant illness. Evidence implicatesbird-feeding mosquitoes of the genus Culex as the vectors of Sindbis virus in enzooticand human infections. However, viral isolations and transmission experiments haveshown that Aedes spp., which are less host specific and feed readily on both birds andhumans, may be important as vectors linking the enzootic cycle with human infection.Mechanisms that allow the virus to overwinter and survive between periods of enzootictransmission have not been identified.Vector Ecology Profiles.Based on viral isolations, the suspected vectors of Sindbis virus in the Middle East areCulex antennatus, Cx. pipiens complex, Cx. univittatus, and Anopheles pharoensis. TheCx. pipiens complex occurs throughout the region. Culex univittatus is distributed in thecoastal plains of Iran, Iraq, Israel, Kuwait, Lebanon, Oman, Saudi Arabia, Syria, Turkey(coastal plains and central plateau) and Yemen. Culex pipiens molestus is found on thecoastal plains of Iran, Israel, Lebanon and Saudi Arabia. It may also occur in adjacentcountries. Culex antennatus occurs in Iran, Israel, Saudi Arabia and, possibly, adjacentcountries. The biology of these Culex spp. is discussed in the preceding section on WestNile fever.Anopheles pharoensis occurs only in Saudi Arabia, Yemen and, rarely, Israel. Anophelespharoensis larvae develop in swamps, reedy marshes, and rice fields with emergentvegetation. This species feeds on man and animals, indoors and outdoors, and also restsindoors or outdoors. This is a very large mosquito and a strong flier that can travel 10 kmor more to find hosts.Vector Surveillance and Suppression. See West Nile fever (page 104).O. Other Arthropod-borne Viruses.Many enzootic arboviruses are circulating in the Middle East but little is known aboutthem. Available epidemiological information indicates that they would have a minorimpact on military operations. However, medical personnel should be aware of thesearboviruses because they will frequently be treating fevers of unknown origin.105