[Epidemiologie investigation on murine typhus in Hongta areas of Yuxi city, Yunnan province of China].

OBJECTIVE: To identify epidemic status of murine typhus in Hongta areas of Yuxi city and to provide evidence for control and prevention of the disease. METHODS: Serologic survey was conducted among residents and rodents. Isolation of Rickettsia moseri was performed. RESULTS: The overall infection rate among general population was 28.92% (96/332) with geometric meantiter (GMT) as 10.83 and there was no difference between males and females (26.71%, 43/161 vs. 30.99%, 53/171, P > 0.05). Significant differences were found between age groups (P < 0.05) with positive rates of 29.63% (8/27), 18.06% (13/72), 39.62% (42/106), 27.50% (22/80) and 23.40% (11/47) among age groups 0-6, 7-18, 19-39, 40-59 and over 60, respectively. The overall rate of infection in mouse was 44.95% (89/198) with GMT as 30.30. Five isolates of R. moseri from mouse specimen, three from fleas plus one case of murine typhus were diagnosed. Rattus norvegicus and Rattus flavipectus were the predominant species of rodent animals (99.49%, 197/198) and Xenopsylla cheopis was the major species of vector (74.26%, 303/408). Flea index and mouse density were 2.06 and 11.13% respectively. CONCLUSION: High infection rates on R. moseri were demonstrated in rodents and residents as well as high risk of murine typhus outbreak might occur in these areas.