Austin Ronald J, Whiting Terry L, Anderson Robert A, Drebot Michael A
Manitoba Agriculture and Food, Veterinary Services Branch, 545 University Crescent, Winnipeg, Manitoba R3T 5S6.
Can Vet J. 2004 Feb;45(2):117-23.
West Nile virus activity in Manitoba was documented for the first time by the collection of an infected crow found on July 8, 2002, in Winnipeg. West Nile virus was identified as the cause of death for a large number of domestic geese at a single farm in southern Manitoba in August. Of the 5 differently aged cohorts on the affected farm, which included 2 breeding flocks and 3 growing flocks, the 6-week-old cohort was most severely affected with 692 of 2731 goslings dying within a 10-day period. Seroprevalence of West Nile virus in 2 clinically affected and recovered juvenile cohorts was 98% and 100%. In breeding geese without clinical disease, seroprevalence was 90% for 15-month-old birds and 10% for 5-year-old birds. Seroreaction in 3 of 4 cohorts tested exceeded what would be expected by mosquito transmission alone.
2002年7月8日在温尼伯发现一只受感染的乌鸦，这是马尼托巴省首次记录到西尼罗河病毒活动。8月，西尼罗河病毒被确认为马尼托巴省南部一个农场大量家鹅死亡的原因。在受影响农场的5个不同年龄组中，包括2个繁殖群和3个生长群，6周龄组受影响最严重，2731只小鹅中有692只在10天内死亡。2个临床受影响并康复的幼龄组中西尼罗河病毒的血清阳性率分别为98%和100%。在无临床疾病的种鹅中，15月龄鹅的血清阳性率为90%，5岁鹅的血清阳性率为10%。在检测的4个组中的3个组中，血清反应超过了仅由蚊子传播所预期的水平。
