Serological study on WNV presence in horses in Vojvodina after the human outbreak in Serbia in 2012

Abstract

To establish the presence of West Nile virus (WNV) infection in the animal population in Serbia after the human WNV outbreak, the presence of anti-WNV IgG antibodies was examined by commercial ELISA of blood sera samples of 130 horses collected in 2012 from 6 stables and 1 settlement in Vojvodina Province, northern Serbia. During the blood sampling, hibernating mosquitoes in the vicinity of the sampled horses were collected (31 pools from 4 locations) and tested for WNV presence by real-time RT-PCR. The presence of anti-WNV antibodies was observed in 49.23% (64/130) horses. Per stable, the percent of seropositive animals ranged from 35% to 64%. All 31 analyzed pools of hibernating mosquitoes tested negative for WNV RNA. The WNV-antibody prevalence of 49.23% obtained in horses during 2012 was much higher than the prevalence (12%) found in horses during 2009/2010. These results, including the confirmed seroconversion in eight horses that tested negative in 2010, indicated an intensive WNV circulation during 2012 in Serbia, and the necessity of implementing surveillance programs.