Gerry A C, Mullens B A, Maclachlan N J, Mecham J O
Department of Entomology, University of California, Riverside 92521, USA.
J Med Entomol. 2001 Mar;38(2):197-209. doi: 10.1603/0022-2585-38.2.197.
Vectorial capacity of Culicoides sonorensis Wirth & Jones for the transmission of bluetongue (BLU) virus was examined at a southern California dairy from January 1995 to December 1997. Insects were collected one to two times per week in five CDC-type suction traps (without light) baited with CO2 at a constant release rate of 1,000 ml/min. BLU virus was detected in midges collected from May through December with an estimated overall infection rate of 0.08%. The BLU virus infection rate of field-captured midges was not correlated with sentinel calf seroconversions to BLU virus. Sentinel calf seroconversions were highly seasonal, occurring from August through November with most calves seroconverting during September and October. Vector competence of field-collected nulliparous flies fed a locally acquired serotype of BLU virus in the laboratory was stable among years (17-23%). Vectorial capacity was strongly correlated with BLU virus transmission (measured by sentinel calf seroconversions) during 1995 and 1996, but not during 1997. Host biting rate estimated for traps nearest to the sentinel calves was the index best correlated with BLU virus transmission for all study years and was most highly correlated with sentinel seroconversions 4 wk later. The utility of vectorial capacity and its component variables is discussed for this system.
1995年1月至1997年12月期间，在美国加利福尼亚州南部的一个奶牛场，对索尼氏库蠓（Culicoides sonorensis Wirth & Jones）传播蓝舌病（BLU）病毒的媒介能力进行了研究。每周用二氧化碳以1000毫升/分钟的恒定释放速率作为诱饵，在五个疾控中心型吸气式捕虫器（无灯光）中收集昆虫一至两次。在5月至12月收集的蠓中检测到蓝舌病病毒，估计总体感染率为0.08%。野外捕获的蠓的蓝舌病病毒感染率与哨兵小牛对蓝舌病病毒的血清转化无关。哨兵小牛的血清转化具有高度季节性，发生在8月至11月，大多数小牛在9月和10月发生血清转化。在实验室中，用本地获得的蓝舌病病毒血清型喂养野外采集的未产卵雌蝇，其媒介能力在各年份间保持稳定（17%-23%）。在1995年和1996年期间，媒介能力与蓝舌病病毒传播（通过哨兵小牛血清转化来衡量）密切相关，但在1997年期间并非如此。对于所有研究年份，估计离哨兵小牛最近的捕虫器的宿主叮咬率是与蓝舌病病毒传播相关性最好的指标，并且与4周后的哨兵血清转化相关性最高。本文讨论了该系统中媒介能力及其组成变量的实用性。
