Seroprevalence and risk factors for peste des petits ruminants in sheep and goats in Djibouti

Abstract

Despite the occurrence of peste des petits ruminants (PPR) in all other countries in the Horn of Africa, which engage in free animal movement, to date, PPR has not been reported in Djibouti. The objective of this study was to estimate the seroprevalence of PPR and its associated risk factors in sheep and goats in that country. A cross-sectional method was used with proportional sampling to allocate the number of small ruminants to be sampled from each of the country's regions (Ali Sabieh, Arta, Dikhil, Djibouti, Obock and Tadjourah). From a total of 1,516 serum samples tested, using a competitive enzyme-linked immunosorbent assay (cELISA), 91 were positive, with an overall 6% (95% confidence interval [CI] = 4.8-7.2) prevalence of antibodies to the PPR virus (PPRV). Antibodies to PPRV were detected in small ruminants from all the regions, excluding Obock. Seroprevalence was highest in the Tadjourah region (8.92%), whereas the lowest prevalence was observed in the Djibouti region (1.28%). The species, age and sex of the animals and the herd size were identified as risk factors for PPR seropositivity. The risk of goats testing positive for PPRV antibodies was 2.95 (CI = 1.39-6.35) times that of sheep. Moreover, the risk of animals younger than two years testing positive for PPRV antibodies was 2.29 (CI = 1.47-3.56) times that of animals older than two years. Similarly, it was shown that female animals were more frequently infected (odds ratio [OR] = 3.82; CI = 1.51 to 9.67) than their male counterparts. In addition, small ruminants from small herds/flocks were more likely to be seropositive (OR = 2.06; CI = 1.10-3.83) than those from mediumsized herds/flocks. The present study revealed, for the first time, the widespread occurrence of PPRV antibodies in small ruminants in Djibouti with low prevalence.