Ecological niches and blood sources of sand fly in an endemic focus of visceral leishmaniasis in Jiuzhaigou, Sichuan, China.

Huiying Chen,Yan Wang,Hua Shi,Yu Ha,Yajun Ma,Kaili Li,Jinjin Jiang,Yong Zhang,Yubin Wang,Zhenzhou Yang,Jiannong Xu

doi:10.1186/s40249-016-0126-9

Abstract

BackgroundSand fly Phlebotomus chinensis is a principle vector for the visceral leishmaniasis (VL) in China with a wide geographic distribution. Jiuzhaigou, Sichuan is a mountain type endemic area of VL in China. Long term effective control efforts in the region have successfully reduced VL transmission. To assess the current status of the sand flies and their ecological aspects in the region, a survey was conducted in the summer of 2014 and 2015.MethodsSand fly specimens were collected by light traps in a village and blood sources were identified by PCR and sequencing of the mitochondrial cytochrome b gene.ResultsIn a rock cave, 65.2 %–79.8 % of collected sand flies were male. On a rabbit farm, 92.9 %–98.8 % of specimens were female. In pig pens, 61.1 % of specimens were female. Some females had visible blood residues. The feeding rate was 49.4 % from the pig pens, 12.3 % from the cave, and only 1.7 % from the rabbit farm. Pig, rabbit, chicken, dog, and human blood were detected in the fed specimens. Swine blood, present in all tested samples, was a preferred blood source, while chicken and dog blood were present in a third of the samples.ConclusionsIn Jiuzhaigou County, Sichuan Province of China, the considerable sandfly density and the peridomestic feeding behavior all increases the risk of VL transmission, and insecticide spraying in animal sheds could be exploited to reduce sand fly populations in human surroundings.Electronic supplementary materialThe online version of this article (doi:10.1186/s40249-016-0126-9) contains supplementary material, which is available to authorized users.

Highlights

Sand fly Phlebotomus chinensis is a principle vector for the visceral leishmaniasis (VL) in China with a wide geographic distribution
VL is largely endemic in western China; focal and sporadic cases occur in Xinjiang, Inner Mongolia, Gansu, Sichuan, Shaanxi, and Shanxi [1, 2]
Sand fly collection and species identification The sand fly specimens were collected in Shangzhai Village, Yongfeng, Jiuzhaigou County, Sichuan Province, China in July of 2014 and 2015 (Fig. 1)

Summary

Introduction

Sand fly Phlebotomus chinensis is a principle vector for the visceral leishmaniasis (VL) in China with a wide geographic distribution. Jiuzhaigou, Sichuan is a mountain type endemic area of VL in China. Long term effective control efforts in the region have successfully reduced VL transmission. To assess the current status of the sand flies and their ecological aspects in the region, a survey was conducted in the summer of 2014 and 2015. Visceral leishmaniasis (VL) is a disease caused by trypanosomatid protozoa in the genus Leishmania and is transmitted by vector species of phlebotomine sand flies. The successful reduction of VL in the region was largely attributed to the control and treatment of infected dogs. Both veterinary care and insecticide-impregnated collars effectively intervened the VL transmission. Understanding the current status of the bionomics of sand flies will facilitate development of effective control measures. We report the habitat types and blood sources of sand flies in the region

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Discussion

Conclusion