长角血蜱、草原革蜱经期传播莱姆病螺旋体的实验研究

为了明确长角血蜱、草原革蜱在我国北方莱姆病传播中的地位和作用,以全沟硬蜱为对照,在实验室内对它们经期传播莱姆病螺旋体的可能性进行了研究.结果表明,全沟硬蜱可保持活的螺旋体到下一发育阶段,并且其体内的莱姆病螺旋体具备感染敏感KM鼠的能力.长角血蜱和草原革蜱虽然可以通过吸血获得莱姆病螺旋体,但它们对莱姆病螺旋体的保持期较短,不能跨越蜕皮阶段,因而不具备经期携带、传播的能力.所以它们作为莱姆病媒介的可能性不大.在长角血蜱或草原革蜱体内检测到的莱姆病螺旋体可能是它们与全沟硬蜱共同吸血的原因所致.

INCAPABILITY OF HAEMAPHYSALIS LONGICORNIS AND DERMACENTOR NUTTALLI TO ACQUIRE AND TRANS-STADIAL TRANSMIT THE LYME SPIROCHETES BORRELIA GARINII

To determine whether H. longicornis and D. nuttalli can serve the transmission of Lyme disease as potential vector ticks in North China, the ability of H. longicornis and D. nuttalli to transmit Lyme spirochetes transstadially was estimated under laboratory conditions with vector tick I. persulcatus as control. Results suggest that the two tick species can also acquire active Lyme spirochetes by feeding on infected KM mice. However, they vary in their ability to maintain spirochetes. Only I. persulcatus can maintain active spirochetes during molting, with subsequent tick stages infectious to innocent KM mice. Haemaphysalis longicornis and D. nuttalli maintain spirochetes no longer than the digestion period of blood; after molting, no spirochetes were detected in both of the two tick species. Therefore, both of the two tick species cant be considered as vector ticks, the presence of spirochetes in H. longicornis and D. nuttalli may be tied to co-feeding with I. persulcatus.