Investigating serological evidence of Schmallenberg virus in cattle in eastern Algeria.

Schmallenberg virus (SBV) is a newly identified virus belonging to the Orthobunyavirus genus, of the Bunyaviridae family, and transmitted by haematophagous arthropods in particular mosquitoes and biting midges of the Culicoides genus. The SBV is known to cause reproductive disorders in ruminants mainly abortions, stillbirths and congenital malformations (hydranencephaly and arthrogryposis syndromes). The aim of this study was to investigate the presence of SBV in dairy cattle in Algeria. Between September 2023 and December 2023, blood serum samples from 300 dairy cows from 75 dairy farms in north eastern Algeria were tested for SBV antibodies using a commercial indirect enzyme-linked immunosorbent assay kit. Individual seroprevalence was 38.33% (115/300; 95.00% confidence interval: 32.83 - 43.83), while herd seroprevalence was 41.33% (31/75; 95.00% confidence interval: 30.18 - 52.47). In addition, the results of this study revealed that SBV seroprevalence at individual or herd level was high and not negligible confirming the presence of SBV in the regions studied in Algeria. In conclusion, more in-depth studies are recommended concerning the molecular proof, origin and pathogenesis of SBV in ruminants mainly those linked to reproductive disorders as well as the study of the various associated risk factors.