Seroprevalence and associated risk factors of Peste des petits ruminants in goats and sheep in two zones, Oromia Region, Ethiopia

Abstract

Peste des Petits Ruminants (PPR) is a severe, contagious, and transboundary viral disease of goats, sheep, camels, and wild small ruminants in more than 70 countries, including Ethiopia. Hence, a cross-sectional study was conducted from September 2023 to June 2024 to assess the seroprevalence of PPR and investigate risk factors of the disease in the West Arsi and West Hararghe zones. A total of 751 serum samples were collected from 398 goats and 353 sheep of 422 flocks found in six districts of the two zones that had not a history of PPR vaccination. A hemagglutinin-based blocking enzyme-linked immunosorbent assay was used to test the serum for antibodies against PPR. A structured questionnaire survey was used to determine potential risk factors of the disease. The overall PPR seroprevalence in the West Arsi and West Hararghe zones was 9.7% at the flock level (95% CI: 7.1-12.9) and 5.9% at the animal level (95% CI: 4.4-7.8). At the species level, the seroprevalence of PPR was found to be 5.3% in goats (95% CI: 3.5-8.0) and 6.5% in sheep (95% CI: 4.4-9.6). Multivariable logistic regression analysis indicated that a geographic zone was a significant predictor of PPR infection in goats and at the flock level. Flocks in the West Hararghe Zone were 4.5 times more likely to be seropositive than those in West Arsi (95% CI: 2.0-9.8, p < 0.001). Age was a significant predictor of PPR exposure in both goats and sheep, whereas altitude was specifically a risk factor in sheep. The present study findings indicate a generally low PPR seroprevalence in both goats and sheep in the study areas. However, the disease was present in 20 out of the 26 kebeles (wards) surveyed, showing ongoing circulation. Therefore, vaccination campaigns should be expanded to cover both zones, with emphasis on West Hararghe. A further study is recommended to identify the influence of agroecology on PPR persistence and transmission.