The prevalence of antibodies against SAT1 foot-and-mouth disease virus in cattle in Khartoum state: epidemiological significance.

Two hundred and eleven sera collected in 2005 from cattle in Khartoum state, in Central Sudan, were examined for antibodies against SAT1 serotype of foot-and-mouth disease virus using the liquid-phase blocking ELISA. The ELISA was modified for the single dilution test by using an optimum antigen dose that produced parallel serum titration curves. Precision and reproducibility of the assay were compared with the recently developed solid phase competition ELISA. Sera were obtained from both; local and cross bred cattle. Twenty sera were found to be positive with a prevalence of 9.5 at an absolute accuracy of 4. The low prevalence and the focal distribution of positive sera suggested a very low incidence of SAT1 type virus. Since the virus has long existed in Sudan and Khartoum, a perpetuation cycle that got SAT1 types of virus less virulent to cattle is proposed.