Jones L D, Hodgson E, Nuttall P A
Natural Environmental Research Council Institute of Virology, Oxford, U.K.
J Gen Virol. 1989 Jul;70 ( Pt 7):1895-8. doi: 10.1099/0022-1317-70-7-1895.
Previous studies have demonstrated that Thogoto (THO) virus is transmitted from infected to uninfected ticks cofeeding on an uninfected guinea-pig, although the guinea-pig does not develop a detectable viraemia. To investigate this mode of transmission, guinea-pigs were infected with uninfected Rhipicephalus appendiculatus nymphs prior to inoculation with either a mixture of THO virus and tick salivary gland extract, or with THO virus alone. The number of ticks that acquired the virus from feeding on animals inoculated with a mixture of virus and salivary gland extract was 10-fold greater than the number that became infected by feeding on animals inoculated with virus alone. The increase in the number of ticks that became infected was greatest when the salivary glands used in the inoculum were derived from uninfected ticks, which had partially fed for a period of 6 days. Viraemia was not detected in any of the guinea-pigs tested during the experiments. These results indicate that THO virus transmission is enhanced by factor(s) associated with the salivary glands of ticks, and that these factor(s) may facilitate 'non-viraemic' transmission between infected and uninfected ticks.
先前的研究表明，托戈托（THO）病毒可在共同叮咬未感染豚鼠的情况下，从受感染蜱虫传播至未受感染蜱虫，尽管豚鼠并未出现可检测到的病毒血症。为研究这种传播方式，在接种THO病毒与蜱唾液腺提取物的混合物或仅接种THO病毒之前，先让豚鼠感染未感染的附肢扇头蜱若虫。从接种病毒与唾液腺提取物混合物的动物身上获取病毒的蜱虫数量，比从仅接种病毒的动物身上获取病毒的蜱虫数量多10倍。当接种物中使用的唾液腺来自未感染且已部分取食6天的蜱虫时，受感染蜱虫数量的增加最为显著。在实验过程中，未在任何受试豚鼠中检测到病毒血症。这些结果表明，THO病毒的传播因与蜱唾液腺相关的因素而增强，且这些因素可能促进感染蜱虫与未感染蜱虫之间的“非病毒血症性”传播。
