Seroprevalence of Maedi -Visna in sheep in selected districts of Amhara region , Ethiopia

Abstract

Maedi-Vsna(MV) causes a significant economical loss through  morbidity, mortality and carcass weight loss in sheep worldwide. The present study was conducted to investigate the seroprevalence and risk factors of Maedi-visna in sheep in four selected districts of the Amharra region, Ethiopia. A total of 1536 sheep blood sera were randomly collected in the period from April, 2014 to December, 2015 and examined using indirect enzyme linked immune-sorbet assay (i-ELISA) to screen specific antibodies against Maedi-Visna virus. Of total samples tested, 61(4%) were positive for the presence of antibodies against Maedi-Visna virus. Considering the sensitivity and specificity of the test, the real seroprevalence calculated as 3.2%. The seroprevalence of Maedi visna was significantly different between sheep of different age groups (χ2 = 9.874, P<0.05), different body condition scores (χ2 = 4.764, p < 0.05) and sheep with or without respiratory symptoms (χ2=279.56, p < 0.05). However, no significant difference was observed in the prevalence of Maedi-visna between sexes (χ2 = 0.002, p > 0. 05) and different breeds of sheep (χ2 = 0.36, p > 0.05).Maedi Visna causes enormous economic losses. Thus, a comprehensive nationwide epidemiological investigation in areas were Awasi-Menze cross rams distributed for breeding purpose should be taken without delay to depict the real picture of the disease in the country .

Key words: Ethiopia, Maedi-visna, Risk factor, Sensitivity  Seroprevalence, Specificity,