Investigation on the Xenopsylla cheopis Distribution in Luohu District,Shenzhen City

Objective To investigate the distribution of Xenopsylla cheopis in different months and species of rat,to provide the guide on prevention of Plague epidemic in Shenzhen.Methods To survey the flea index,the infection rate of Xenopsylla cheopis on rats monthly,15 rats were captured by the electric mousetrap placed in a large restaurant in the Nanhu street Luohu district from January to December 2008.The significant difference of infection rate of flea among species of rat was compared by x2 test.Results One hundred and ninety four rats captured belonged to two Four hundred and six fleas collected from the 97 of 194 live rats were identified to one species,Xenopisylla cheopis.The sex ratio(F:M) of fleas was1:1.07.The infection rate of flea on R.norvegicus and R.flavipectus was 49% and 52% respectively.The difference wasn't significant(x2=0.11,P0.05).The average infection rate of flea on rats was 50%,varying from 7% in June to 93% in August.The flea index varied from 0.20 in June to 4.88 in September,with the average value of 2.09.The Xenopsylla cheopis index of R.norvegicus and R.flavipectus was 2.42 and 1.10 respectively.Conclusion The density of Xenopisylla cheopis fluctuated with seasons with the double peaks in spring and fall.R.norvegicus was more important than R.flavipectus as the host of Xenopisylla cheopis.