关键词: 小盾纤恙螨, 经卵传递, 汉坦病毒, 恙虫病东方体

Abstract: 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.