Seroprevalence and Associated Risk Factors of Peste des Petits Ruminants in Small Ruminants in North Shewa, Ethiopia:...

Peste des petits ruminants (PPR) are a highly contagious viral disease that causes substantial morbidity, mortality, and economic losses in Ethiopian small ruminants. Despite ongoing efforts to eradicate PPR by 2027, 554 outbreaks were reported nationwide between 2018 and 2022. This cross-sectional study, conducted from January to May 2024, estimated the seroprevalence of PPR virus (PPRV) and identified associated risk factors among nonvaccinated small ruminants in six districts of North Shewa zone using competitive ELISA (C-ELISA).

Of the 324 serum samples tested, 182 were positive for PPRV antibodies, corresponding to an apparent seroprevalence of 56.17% and a true prevalence of 59.18%. Seroprevalence varied across districts, ranging from 27.78% in Menz-Mama to 92.59% in Menz-Gera. In the multivariable mixed-effects logistic regression model, with peasant association (PA) as a random effect, species and district were significantly associated with seropositivity (p < 0.05). Goats had approximately four-fold higher odds of being seropositive than sheep (OR = 4.34; 95% CI: 1.79-12.85; p = 0.002), while animals in Menz-Gera had markedly higher odds compared to those in Menz-Mama (OR = 37.77; 95% CI: 8.99-158.63; p < 0.001). No significant associations were observed for age, sex, body condition score, management system/intervention, or agroecology (p > 0.05). Retrospective analysis indicated that 62 vaccination campaigns were conducted in the zone during the study period, yet 48 PPR outbreaks occurred, resulting in 6415 cases and 951 deaths, corresponding to an overall case fatality rate of 14.82%.

PPR appears to remain endemic in North Shewa, with the observed seroprevalence suggesting continued virus circulation, particularly among goats and in high-risk districts. Despite repeated vaccination campaigns, outbreaks continued to occur during the study period. Therefore, strengthening targeted, risk-based vaccination, together with improved surveillance and routine seromonitoring, is recommended to support effective PPR control and eradication efforts.