de Carvalho Ferreira Helena C, Tudela Zúquete Sara, Wijnveld Michiel, Weesendorp Eefke, Jongejan Frans, Stegeman Arjan, Loeffen Willie L A
Virology Department, Central Veterinary Institute, Part of Wageningen UR (CVI), P.O. Box 65, 8200 AB Lelystad, The Netherlands; Farm Animal Department, Faculty of Veterinary Medicine, University Utrecht, Yalelaan 7-9, 3584 CL Utrecht, The Netherlands.
Utrecht Centre for Tick-borne Diseases (UCTD), Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL Utrecht, The Netherlands.
Ticks Tick Borne Dis. 2014 Sep;5(5):582-9. doi: 10.1016/j.ttbdis.2013.12.012. Epub 2014 Jun 26.
African swine fever (ASF) is caused by African swine fever virus (ASFV), a tick-borne DNA virus. Soft ticks of the genus Ornithodoros are the only biological vectors of ASFV recognized so far. Although other hard ticks have been tested for vector competence, two commonly found tick species in Europe, Ixodes ricinus and Dermacentor reticulatus, have not been assessed for their vector competence for ASFV. In this study, we aimed to determine whether virus replication can occur in any of these two hard tick species (I. ricinus and/or D. reticulatus), in comparison with O. moubata (the confirmed vector), after feeding them blood containing different ASFV isolates using an improved in vitro system. DNA quantities of ASFV in these infected hard ticks were measured systematically, for 6 weeks in I. ricinus, and up to 8 weeks in D. reticulatus, and the results were compared to those obtained from O. moubata. There was evidence of virus replication in the O. moubata ticks. However, there was no evidence of virus replication in I. ricinus or D. reticulatus, even though viral DNA could be detected for up to 8 weeks after feeding in some cases. This study presents the first results on the possible vector competence of European hard (ixodid) ticks for ASFV, in a validated in vitro feeding setup. In conclusion, given the lack of evidence for virus replication under in vitro conditions, D. reticulatus and I. ricinus are unlikely to be relevant biological vectors of ASFV.
非洲猪瘟（ASF）由非洲猪瘟病毒（ASFV）引起，ASFV是一种通过蜱传播的DNA病毒。钝缘蜱属的软蜱是目前已知的ASFV唯一生物传播媒介。尽管已对其他硬蜱的传播能力进行了测试，但欧洲常见的两种蜱，蓖麻硬蜱和网纹革蜱，尚未评估其对ASFV的传播能力。在本研究中，我们旨在通过一种改进的体外系统，给这两种硬蜱（蓖麻硬蜱和/或网纹革蜱）喂食含有不同ASFV分离株的血液后，与已确认的传播媒介莫氏钝缘蜱相比，确定病毒是否能在这两种硬蜱中的任何一种中复制。系统测量了这些受感染硬蜱中ASFV的DNA量，蓖麻硬蜱测量6周，网纹革蜱测量长达8周，并将结果与从莫氏钝缘蜱获得的结果进行比较。在莫氏钝缘蜱中有病毒复制的证据。然而，在蓖麻硬蜱或网纹革蜱中没有病毒复制的证据，尽管在某些情况下喂食后长达8周都能检测到病毒DNA。本研究在经过验证的体外喂食设置中，首次给出了欧洲硬蜱（硬蜱科）对ASFV可能传播能力的结果。总之，鉴于在体外条件下缺乏病毒复制的证据，网纹革蜱和蓖麻硬蜱不太可能是ASFV的相关生物传播媒介。
