Arboviral Diseases Branch, Centers for Disease Control and Prevention, Fort Collins, CO.
Department of Biomedical Sciences, ARBL, Colorado State University, Fort Collins, CO.
J Med Entomol. 2021 Mar 12;58(2):873-879. doi: 10.1093/jme/tjaa191.
Following the recent discovery of Bourbon virus (BRBV) as a human pathogen, and the isolation of the virus from Amblyomma americanum (L.) collected near the location of a fatal human case, we undertook a series of experiments to assess the laboratory vector competence of this tick species for BRBV. Larval ticks were infected using an immersion technique, and transstadial transmission of virus to the nymphal and then to the adult stages was demonstrated. Transstadially infected nymphs transmitted virus to adult ticks at very high rates during cofeeding, indicating the presence of infectious virus in the saliva of engorging ticks. Vertical transmission by transstadially infected females to their progeny occurred, but at a low rate. Rabbits fed on by infected ticks of all active life stages developed high titers of antibody to the virus, demonstrating host exposure to BRBV antigens/live virus during tick blood feeding. These results demonstrate that A. americanum is a competent vector of BRBV and indicate that cofeeding could be critical for enzootic maintenance.
最近发现波旁病毒（BRBV）是一种人类病原体，并从在致命人类病例发生地点附近收集的美洲钝缘蜱（Amblyomma americanum（L.））中分离出该病毒，我们进行了一系列实验来评估该蜱种对 BRBV 的实验室媒介能力。使用浸渍技术感染幼虫，证明了病毒在幼蜱到若蜱再到成蜱的转期传播。在共同取食期间，转期感染的若蜱以非常高的比率将病毒传播给成蜱，表明在饱血的蜱的唾液中存在传染性病毒。通过转期感染的雌性垂直传播给其后代，但比率较低。被感染的各活动期蜱叮咬的兔子产生了针对该病毒的高滴度抗体，表明在蜱吸血期间宿主接触到 BRBV 抗原/活病毒。这些结果表明，美洲钝缘蜱是 BRBV 的有效媒介，并表明共同取食可能对地方性维持至关重要。
