Investigation of the epidemiological and clinical characteristics of an outbreak of tsutsugamushi disease in Anhui Province / 中华传染病杂志

ABSTRACT

Objective To investigate the epidemiological and clinical characteristics of an outbreak of tsutsugamushi disease in Chuzhou region, Anhui Province, and to clarify the new changes of epidemic focus of tsutsugamushi disease in China. Methods Field epidemiological investigation and analysis of clinical features were done. The detections of specific antibodies against Rickettsia tsutsugamushi were conducted to diagnose tsutsugamushi disease using colloidal gold immunochromatography assay combined with Well-Felix reaction. The geomorphic and climatic characteristics of the new epidemic focus were investigated. Results The outbreak occurred from October to November, 2007. The epidemic focus located on mountainous brushland regions, and the air temperature fluctuated from 20-4 ℃. Nineteen cases of tsutsugamushi disease in the new-found epidemic focus were finally diagnosed, 9 cases out of them were hospitalized, another 9 had recovered when diagnosed by serological tests; the remaining one had classical manifestations of tsutsugamushi disease but did not receive the serological test for certain cause. The main clinical symptoms were chilly in 14 cases, fever in 19 cases, headache in 15 cases; among the 9 hospitalized patients, the symptoms were lymphadenectasis in 8 inpatients, skin rash in 7 inpatients, splenomegaly in 4 inpatients and skin eschar and ulcer in 7 inpatients and Weil-Felix reaction by OXκantigen positive in 4 cases; the specific antibodies against Rickettsia tsutsugarnushi of 18 tested cases were all positive. No severe complications occurred in all patients. Before the first case was identified, all other cases were not diagnosed in time and did not receive correct antibiotic treatment. Nine hospitalized patients recovered rapidly with the treatment of doxycycline. Conclusions The outbreak of tsutsugamushi disease in Anhui Province in 2007 is type of emerged in autumn and transitional epidemic focus. There is epidemic focus of tsutsugamushi disease in northern region of Anhui Province. Doxycycline is rapid and effective for the treatment of tsutsugamushi disease.