Costero A, Grayson M A
New York State Department of Health, Wadsworth Center for Laboratories and Research, Albany, USA.
Am J Trop Med Hyg. 1996 Nov;55(5):536-46. doi: 10.4269/ajtmh.1996.55.536.
Transmission experiments were performed with Ixodes scapularis ticks from an uninfected laboratory colony. Immature and adult ticks were exposed to Powassan (POW) viremic hamsters and rabbits, respectively. Oral infection rates for engorged larvae, nymphs and females fed on POW-infected hosts were 10%, 40%, and 57%, respectively. Transstadial transmission rates for nymphs exposed to POW virus as larvae, adults exposed as larvae, and adults exposed as nymphs, were 9.5%, 10%, and 54%, respectively. Evidence of transovarial transmission occurred when two uninfected hamsters, exposed to F2 larvae and nymphs originally exposed to POW virus in the F1 nymphal stage, seroconverted to POW virus with hemagglutination inhibition titers of 80 and 5,120, respectively; the transovarial transmission rate was 16.6%. All developmental stages were able to transmit virus orally to uninfected hosts regardless of when the ticks were originally exposed to the virus. These results suggest that I. scapularis is a competent vector of POW virus under experimental conditions.
使用来自未感染的实验室种群的肩突硬蜱进行传播实验。未成熟蜱和成年蜱分别暴露于波瓦桑（POW）病毒血症的仓鼠和兔子。以感染POW的宿主为食的饱血幼虫、若虫和雌蜱的经口感染率分别为10%、40%和57%。幼虫期暴露于POW病毒的若虫、幼虫期暴露的成虫以及若虫期暴露的成虫的跨期传播率分别为9.5%、10%和54%。当两只未感染的仓鼠暴露于最初在F1若虫期暴露于POW病毒的F2幼虫和若虫时，出现了经卵传播的证据，它们分别以血凝抑制效价80和5120血清转化为POW病毒；经卵传播率为16.6%。无论蜱最初何时暴露于病毒，所有发育阶段都能够经口将病毒传播给未感染的宿主。这些结果表明，在实验条件下，肩突硬蜱是POW病毒的有效传播媒介。
