Surveillance on the host and vector in Yulong plague focus in Yunnan province

Objective To investigate the species and quantity of host animals and vector fleas in Yulong plague focus of Yunnan province, and explore the nature of the plague focus for providing scientific bases for the prevention and treatment of plague. Methods Nine surveillant sites were selected to trap the small mammals in Yulong county district of Lijiang city from February to December in 2007. Small mammals were captured by traps inside house and by cages in the field, fleas were obtained from the small mammals trapped. The species of all small mammals and fleas were identified morphologically. Results A total of 2390 small mammals (rodent) were captured which belonged to 19 species of 11 genera of 5 families of 3 orders, including Eothenmys spp. (47.28%) and Apodemus chevrieri ( 37.11%). Further identification of Eothenmys spp by skull morphology revealed that E. miletus, E. proditor and E. melanogaster accounted for 19.09%, 79.25% and 79.25%, respectively,with E. proditor predominating in Luzi village and Yulong mountains while E. miletus predominating in remaining surveillance spots. A totoal of 625 fleas were caught from host rodents, which belonged to 6 species of 6 genera in 2 families, the majority were Ctenophthalmus quadratus (62.08%) and Neopsylla specialis (22.56%). In addition, Frontopsylla spadix and Leptopsylla segnis accounted for 8.16% and 5.28%, respectively. No Xenopsylla cheopis was found. Conclusion The rodent hosts and flea vectors in Yulong plague focus were similar in species to that in Jianchuan, but with some unique characteristics.