Alterations in some epidemiological patterns and virus heterogeneity recently observed in sheeppox outbreaks in the Sudan

Observations including alterations in some epidemiological patterns, host specificity and virus heterogeneity for sheeppox (SP) in the Sudan were recorded in the present study. Field observations, virus isolation, plaque production and pathogenicity tests were employed. Outbreaks of SP occurring during the unusual summer season were observed. Investigations also affirmed the host specificity of the sheeppox virus (SPV), which could neither naturally nor experimentally infect goats, although it was lethal to sheep. Two clinically and serologically distinct types of sheeppox virus were isolated from these field outbreaks. The viruses, which were identified serologically and virologically as SPV, displayed different characteristics and thus, heterogeneity within the virus in Sudan was recognized.