小盾纤恙螨经卵传递病原体研究

目的　探索快速取得大量小盾纤恙螨未食子代幼虫的方法 ,以适应研究恙螨经卵传递病原体的需要。方法　将小黑板放置在肾综合征出血热 (HFRS)及恙虫病疫区草地上 ,10min后取回计算螨数并鉴定螨种。该法可收集到大量小盾纤恙螨未食子代幼虫。 2 0～ 3 0只幼虫为 1批叮刺 1只小白鼠乳鼠以分离汉坦病毒 (HV)或叮刺 1只小白鼠以分离恙虫病东方体 (Ot)。结果　 2 4批恙螨幼虫叮刺乳鼠 ,分离到 5株HV ;6只小白鼠被恙螨幼虫叮刺 ,分离到 2株Ot。试验中所用幼虫未曾叮刺过 ,但鼠被这些幼虫叮刺后能感染上HV和Ot ,表明这些螨所带病原体系由母代螨经卵传递而来。结论　小黑板可采集到疫区草地上大量小盾纤恙螨未食幼虫 ,为研究恙螨经卵传递病原体提供了一种快速、简便、经济的方法。研究结果证明小盾纤恙螨可经卵传递HV和Ot,可作为HFRS和恙虫病的传播媒介。

Study on Transovarian Transmission of Pathogen in Leptotrombidium scutellare

Objective To explore a quick method to gain a large number of unfed filial larvae of Leptotrombidium scutellare so as to suit the needs of studying the transovarian transmission of pathogen in chigger mites. Methods Small blackboards were placed on the grassland in the endemic areas of HFRS or tsutsugamushi disease each for 10 minutes. The larvae on the blackboards were counted and their species were identified. This method could collect a large mumber of unfed filial larvae of L.scutellare . About 20-30 larvae of L.scutellare were used as a pool to bite a suckling mouse to isolate Hantavirus(HV),to bite a mouse to isolate Orientia tsutsugamushi (Ot). Results Of 24 suckling mice bitten by the larvae,5 strains of HV were isolated. Among 6 mice bitten by the larvae,2 were confirmed by detection of Ot. The larvae used in this study had never bitten,while the mice bitten by these larvae could be infected by HV and Ot,indicating that the pathogen carried by these larvae could only be originated from it parent mite via transovarian route. Conclusion Small blackboard can collect a large number of unfed filial larvae of L.scutellare on the grassland in the endemic areas. It offers a rapid,simple and economic method in studying the transovarian of pathogen in mites. The results demonstrate that:HV and Ot can be transferred via transovarian transmission in mite;and therefore,L.scutellare can serve as a transmitting vector of HFRS and tsutsugamushi disease.