전남지방의 소 합포체성 폐렴바이러스(Bovine Respiratory Syncytial Virus) 감염에 관한 혈청학적 연구

Seroepidemiological Studies on Bovine Respiratory Syncytial Virus of Cattle in Chonnam Province

Sera from 425 Korean native and 203 Holstein cattle were collected from October 1994 to September 1995 from dairy farms and slaughterhouses in Chonnam province to study the exposure rate to bovine respiratory syncytial virus(BRSV). Serum antibody titers against BRSV were measured by neutralization test, and results were as follows: Overall prevalence of seropositive cattle to BRSV were 74.5%, and the exposure rate to BRSV was higher among the Holstein (77.3%) than among the Korean native cattle(73.2%). The serum antibody titers against BRSV ranged from 1:2~<TEX>$geq$</TEX>1:256 in both species. Among Korean native cattle, the most frequent serum antibody titer was 1:4 against BRSV(19.3%), while only 1.4% of seropositive cattle had serum titer of <TEX>$geq$</TEX>1: 256. Among Holstein cattle, 22.7% of examined cattle contained serum titer of 1:8, while 1.5% of seropositive cattle showed <TEX>$geq$</TEX> 1:256. Antibody titers against BRSV were higher among males than females in both Holstein (82.1% vs. 73.1%) and Korean native (74.5% vs. 69.2%) cattle. Prevalence of seropositive cattle by age in both species were evenly distributed, although the highest number (76.9%) of seropositive were at the age of 3 in Korean native cattle, while 83.5% of seropositive Holstein cattle were of 2 years old. The lowest seropositive rate was observed in cattle of less than 1 year old(25.0%). Seasonal occurrunce of BRSV was the highest in spring season in both Holstein (86.6%) and Korean native (81.0%) cattle (P<0.05).