Serotypes of bluetongue virus present in Saudi Arabia

The widespread occurrence of infection with bluetongue virus (BTV) in Saudi Arabia has been demonstrated by immunodiffusion testing. Subsequently, 31 sheep sera and 1 goat serum with clear precipitating activity were examined by neutralization test using the 22 reference serotypes of BTV. Only 12 sheep sera neutralized 1 or more of BTV serotypes: 6 (1 serum), 14 (2 sera), 17 (4 sera), 19 (1 serum) and 20 (11 sera). The goat serum neutralized only serotype 19 of BTV. On the other hand, 19 sheep sera failed to neutralize any known BTV serotype. The significance of these serological findings was discussed and planning for further studies to isolate local BTV strains from sentinel flocks of lambs and calves was proposed.