Analysis and Surveillance on Major Host Animal Species and Vectors of Plague in Shenzhen City

Objective To investigate and analyze the species of the hosts and the vectors of plague in Shenzhen,and to provide the scientific evidence for prevention and treatment of plague. Methods Host animals were captured by daily cage-caught.Fleas were classified after being identified.Yersinia pestis F1 antibodies were detected by IHA and Yersinia pestis was separated by organ impression. Results A total of 472 rat-like animals were captured in 2005,belonging to 2 orders,3 genera,and 4 species.The capture rate was 8.25%.R.norvegicus constituted 87.50% of the total number.A total of 320 rat-like animals were captured in 2010,belonging to 2 orders,4 genera,and 5 species.The capture rate was 7.52%.R.norvegicus,constituted 94.06% of the total number.R. norvegicus was the dominant species in the two surveillances.The average rodent density(χ2=48.7,P0.001) in Nanshan District declined significantly.129 rat-like animals were identified to be parasitized by 565 Xenopslla cheopis in 2005,total flea infection rate was 27.33% and the flea index was 1.20.35 rat-like animals were identified to be parasitized by 79 Xenopslla cheopis in 2010,total flea infection rate was 10.93% and the flea index was 0.25.Total flea infection rate(χ2=31.2, P0.001) and the flea index(χ2=1,130.0,P0.001) showed a downward trend.458 samples were tested for F1 antibody and 407 organ impressions were conducted for Yersinia pestis in 2005.315 samples were tested and 320 organ impressions were conducted in 2010.Pathogenological and serological results were all negative. Conclusions No animal plague epidemic was found in Shenzhen City.The density of vectors shows a downward trend.The average rodent density in Nanshan District declines significantly.