Serological and Epidemiological Studies of Parapoxvirus Infection in Cattle in Ishikawa Prefecture

A survey of antibodies against parapoxvirus species bovine papular stomatitis virus (BPSV) was conducted by agar gel immunodiffusion (AGID) test on 750 serum samples collected from cattle in Ishikawa Prefecture, Japan, in 2007. On farms, 0-21.9% dairy cattle and 8.3-33.3% beef cattle were seropositive, but the difference was not significant. The positive reaction rate was significantly higher in dairy cattle reared on public pastures (33.3-82.4%) than in dairy and beef cattle reared on farms. Among dairy cattle on farms, the positive reaction rate was significantly higher in cattle reared on public pastures and in cattle introduced from other prefectures than in cattle that were neither reared on pastures nor introduced from other prefectures. The same scrum samples were tested for antibodies against orf virus (ORFV) by AGID, and the positive reaction rate for ORFV was almost the same or less than that for BPSV, and the immunodiffusion line on the gel was weaker for ORFV. There was no correlation between positive reaction rates in cattle and grazing on public pastures that geographically overlap with the habitat of Japanese serows (Capricornis crispus), which are also hosts of parapoxvirus. These results suggest that the risk of BPSV infection is higher for dairy cattle reared on pastures than on farms, but the risk of infection due to grazing on pastures inhabited by Japanese serows seems to be low.