Investigation of hemorrhagic fever with renal syndrome in 2003 in Binzhou city

Objective The present investigation was designed to understand the dynamics and distri bution of hemorrhagic fever with renal syndrome(HFRS) in Binzhou city Methods lndoor and outdoor surveillance of mice and rats was done in the plain of the north to the Yellow River in Binzhou city Rats were captured by conventional night trapping method And rat lungs were removed using aseptic tach nique Hantavirus (HV) antigen and antibody were detected by indirect immnuoflourescence Assay technique Sera were taken from hospital patients whose diagnosis of HFRS wss made base on clinical manifestation，lab tests and epidemiological criterion ReSults it was found that lndoor rat density was 49％，with brown rats(Rattus norvegicus)predominant accounting for 63.1％ And filed rat density was 4.6％ with Apodemus agrarius taking up 58.6％ Tne rate of vires-carriers in large and small house rats was 0 6％. Apodemus agrarius was the main species of field rats The rate of virus-carriers in small house rats was 6.7％ Seven counties and districts and 56 rural and town administrative districts of the city were affected by HFRS wlth a total of 315 cases。The lncidence of tne epidemic in Zoupingshan area reached 69.0/100.000，with individual rural administrative district having a high incidence of 201.6/100,000. Tne incidence in the plain Huiming county to the north of the Yellow River，where HFRS had disappeared for many years，came to 4.2/100,000. The epidemic attacked mostly during March to Apirl and October to November (88％). Individuals at 21 to 40 years of age were more often affected (73.3％) with the ratio of males to females being 2.1:1，and peasants accounting for majority of the cases(72.4％) 60.2％ of HFSR cases were diagnostically confirmed by immunofluorescent antibody assay. The coincidence rate of clinical diagnosis and antibody detection of HFRS was 72.2％。Conclu-sion Virus-carrier rats are closdy related to the occurrence of HFRS