Distribution of bluetongue virus in Turkey, 1978-81.

Information about the distribution of bluetongue in Turkey during 1978-81 has been obtained by serological surveys in cattle, sheep and goats. The group-specific immunodiffusion test was used to identify the presence of bluetongue virus (BTV) in a given province and the type-specific microneutralization test to decide which virus types had been in circulation. By drawing sera from accurately aged donor animals in May and August 1980, it was possible to draw up a general outline of the distribution of BTV in Turkey between early 1978 and mid 1980. By combining the same technique with spring and autumn field visits it became possible to make detailed inferences about the distribution of BTV serotypes in 1980 and 1981. The results support the conclusion that BTV was widespread in central and western Turkey for a number of years and suggests that overwintering can be a regular occurrence in that country. When compared with contemporaneous results from Syria and Jordan, a unifying and well-defined bluetongue virus ecosystem becomes apparent.