Analyses of baseline survey data on rinderpest in Bahr el Ghazal Province, with proposal of an improved vaccination strategy against rinderpest for southern Sudan

Abstract

Results from analyses of baseline surveillance data on rinderpest are used for proposing an improved vaccination strategy against rinderpest in southern Sudan. Sera from 4,074 (47%) of the total sample of 8,565 cattle collected in a series of cross-sectional surveys in 400 cattle camps in the Bahr el Ghazal Province of southern Sudan were tested for rinderpest antibodies using the standard virus neutralisation test (VNT) technique: 77.4% were positive while 22.6% gave negative results. The data were cross-classified according to five variables: herd management, breed, age, sex and geographic region (grazing location). The percentage antibody-positivity level (taken as an approximation of past experience with rinderpest antigen and the corresponding prevalence ratio estimates of relative risk) for each variable are discussed within the context of the known characteristics of immunity to rinderpest in endemic areas and the husbandry practices of the cattle owners in the study area. Results suggest that rinderpest "hot-spots" of transmission and/or low level of herd immunity should be mapped out for concentrated efforts to vaccinate calves and young adults so that the high level of antibody-positivity observed in this study can be maintained and transmission permanently interrupted.