Seroprevalence of Bluetongue and Schmallenberg viruses in ruminants in Al-Batinah Governorates, Oman

Bluetongue (BTV) and Schmallenberg viruses (SBV) are the causative agents of Bluetongue and Schmallenberg diseases, respectively. Both BTV and SBV are vector-borne viruses that are transmitted mainly by Culicoides (Diptera; Ceratopogonidae) and infect domestic, wild ruminants, and camelid species. Bluetongue virus belongs to the genus Orbivirus, family Reoviridae, whereas Schmallenberg virus belongs to the genus Orthobunyavirus, family Bunyaviridae. In this study, we used enzyme-linked immunosorbent assay (ELISA) to determine the seroprevalence of both viruses in ruminants in Al-Batinah Governorates, Sultanate of Oman. A total of 529 serum samples were randomly collected from 207 sheep, 265 goats, and 57 cattle from five wilayat of Al-Batinah North and Al-Batinah South Governorates. The serum samples were screened for the presence of BTV-specific antibodies against the BTV VP7 protein using ID Screen® Bluetongue Competition (cELISA) and screened for the presence of SBV-specific antibodies against the recombinant SBV nucleoprotein antigen using ID Screen® Schmallenberg virus Indirect Mult (iE-LISA). The overall seroprevalence of BTV and SBV infections was 69.8% and 44.8%. In cattle, the prevalence of BTV and SBV antibodies was comparatively higher (94.7% and 82.5%) than in goats (83% and 43%) and sheep (45.9% and 36.7%). The highest BTV seroprevalence was recorded in Nakhal (85.5%), followed by Wadi Al-Maawil (81%), and was lowest in Barka (59.6%). However, the highest seroprevalence of SBV was observed in Wadi Al-Maawil (50%), followed by Barka (48.7%), and lowest in Sohar (34.2%). Overall, the seroprevalence of BTV and SBV in domesticated ruminants was higher in adults than in young animals. Females showed a higher seroprevalence of BTV and SBV compared to males. The study provides an update on the epidemiological status of BTV, and to our knowledge, this is the first study on the seroprevalence of SBV in ruminants in Oman. Future studies are required for the isolation and identification of BTV and SBV along with other potential biological vectors in Oman.