[Analysis of the epidemic characteristics of fever and thrombocytopenia syndrome in Henan province, 2007 - 2011].

OBJECTIVE

To analyze the epidemiological characteristics of fever thrombocytopenia and leukopenia syndrome (FTLS) in Henan province, China in 2007 - 2011.

METHODS

Data from specific surveillance system for FTLS in Henan and Information Management System of Chinese Center for Disease Control and Prevention were used to collect the information of the cases.Descriptive epidemiological methods were used to analyze the surveillance data during 2007 - 2011. Patients' sera were collected to detect new bunyavirus using fluorescent RT-PCR and virus isolation.

RESULTS

During 2007 - 2011, 1021 FTLS cases were reported in Henan province. The fatality rate was 2.25%with 23 deaths. The cases reported in Xinyang city were 1007, accounting for 98.75%.Cases were mainly occurred between April and October, accounting for 96.47% (985/1021). Epidemic peak was May to July, accounting for 59.16% (604/1021). The second peak occurred in September, accounting for 12.05% (123/1021). The age of the cases ranged from 1 to 88 years old with the median age of 59. Sex ratio (male:female) was 1:1.50 (408:613). In all cases, 93.73% (957/1021) were farmers. In 465 patients' sera, the positive rate of new bunyavirus was 69.25% (322/465) using fluorescent RT-PCR. In 164 patients' sera, 67 strains of new bunyavirus were isolated with isolation rate of 40.85% (67/164).

CONCLUSION

FTLS in Henan province is caused mainly by the new bunyavirus and has certain regional and seasonal characteristics. Most cases are female older farmers.