[Investigation on transmitting vectors of visceral leishmaniasis in Jiashi County, Xinjiang].

OBJECTIVE

To investigate sandfly vectors transmitting visceral leishmaniasis, including species and seasonal distribution in Jiashi county of Xinjiang Uygur Autonomous Region.

METHODS

Sandflies were collected in the field, counted and identified. The specimens were dissected to analyze the gonotrophic cycle and to find infection of promastigotes. The resting places were observed by using oil-paper and sandfly-capturing trap.

RESULTS

4540 sandflies were collected with 99.9% of Phlebotomus wui and only 0.1% Sergentomyia minutus sinkiangensis. On the seasonal distribution, the first peak appeared by the end of May and the first ten-day of June, and the second peak was in the middle of August. Observation showed that the activity of sandflies occurred mainly from 22:00 to 4:00, reaching to the maximum in the midnight. Analysis on the gonotrophic cycle revealed that Ph. wui was an exophilic species and appeared nocturnally for feeding with preference to human blood. Natural infection with promastigotes was found in 4 sandflies, more in the field than the residential area. Resting places included the aperture on the wall of livestock sheds and in the caves.

CONCLUSION

Ph. wui is the predominant species in Jiashi, with higher infection rate of natural promastigotes in the field and with two life generations annually.