Shepherd A J, Swanepoel R, Shepherd S P, Leman P A, Mathee O
Department of Virology, University of the Witwatersrand, Republic of South Africa.
Epidemiol Infect. 1991 Apr;106(2):373-82. doi: 10.1017/s0950268800048524.
In order to determine the way in which vertebrates infected with Crimean-Congo haemorrhagic fever (CCHF) virus and potential ixodid tick vectors interact in nature, immature and adult ticks of several species were fed on viraemic mammals and then assayed for virus content at varying times after feeding. CCHF virus was not isolated from ticks of six species tested after feeding as adults and immature forms on sheep with viraemia of 10(2.5-3.2) LD 50/ml, nor from larval ticks fed on guinea-pigs and white-tailed rats with viraemia of 10(1.9-2.7) LD 50/ml. In contrast, virus was isolated from 10 of 152 pools of engorged adult ticks of 5 species that fed on cattle with viraemia of 10(1.5-2.7) LD 50/ml and from 3 of 137 female ticks after oviposition. Infection was transmitted to larval and nymphal Hyalomma truncatum and H. marginatum rufipes, but not to Rhipicephalus evertsi evertsi, from a scrub hare with viraemia of 10(4.2) LD 50/ml but only nymphal H. truncatum and H. m. rufipes became infected from scrub hares with viraemia of 10(2.6-2.7) LD 50/ml. Infection was transmitted trans-stadially in H. m. rufipes and H. truncatum infected as nymphae, and adult H. m. rufipes transmitted infection to a sheep. No evidence of transovarial transmission was found in larval progeny of ticks exposed to CCHF virus as adults on sheep and cattle or as immatures on scrub hares.
为了确定感染克里米亚-刚果出血热（CCHF）病毒的脊椎动物与潜在的硬蜱传播媒介在自然环境中的相互作用方式，让几种蜱的未成熟体和成蜱吸食患病毒血症的哺乳动物血液，然后在吸食后的不同时间检测其病毒含量。在对6种蜱进行检测时，将其成虫和未成熟体喂食给病毒血症水平为10(2.5 - 3.2) LD50/ml的绵羊后，未从这些蜱中分离出CCHF病毒；将幼虫喂食给病毒血症水平为10(1.9 - 2.7) LD50/ml的豚鼠和白尾大鼠后，也未分离出该病毒。相比之下，在152组吸食了病毒血症水平为10(1.5 - 2.7) LD50/ml的牛血的5种饱血成年蜱中，有10组分离出了病毒，在产卵后的137只雌蜱中有3只分离出了病毒。病毒血症水平为10(4.2) LD50/ml的灌丛兔可将感染传播给截形璃眼蜱和边缘璃眼蜱的幼虫和若虫，但不能传播给草原革蜱；而病毒血症水平为10(2.6 - 2.7) LD50/ml的灌丛兔仅能使截形璃眼蜱和边缘璃眼蜱的若虫感染。在边缘璃眼蜱和截形璃眼蜱若虫期感染的情况下，感染可经变态期传播，边缘璃眼蜱成虫可将感染传播给绵羊。在绵羊和牛身上以成虫形式接触CCHF病毒的蜱，以及在灌丛兔身上以未成熟体形式接触该病毒的蜱，其幼虫后代均未发现经卵传播的证据。
