Analysis on epidemiologic feature of hand-foot-mouth disease(HFMD) in Hunan province in 2008

【Objective】 To analyze epidemiologic features of hand-foot-mouth disease(HFMD) in Hunan province,and to understand the main type of the HFMD pathogen so as to provide scientific evidence for disease control and prevention.【Methods】 Descriptive epidemiological study was applied to analysis of epidemiologic features of HFMD.Herpes fluid,throat swab,anal swab,stool samples of clinically diagnosed HFMD cases were collected.Nucleic acids of three types of virus i.e.enter virus(EV),enter virus 71(EV71) and Coxsackie virus A16(CoxA16),were detected by RT-PCR method both in original samples and isolated positive virus strains.Virus was isolated by RD and Hep-2 cells from stool samples.【Results】 A total of 27 133 HFMD cases were reported in Hunan province in 2008,the annual incidence rate was 42.66/100 000.Although there were cases being reported in each month,the high period was from May to July.Cases were distributed in 121 counties(only one county had no case reported) in all over the province and were mainly sporadic.Sex ratio was 1.81∶1,and 89.43% of all reported cases were children cases aged5 years.Samples from 719 clinically diagnosed cases with HFMD were collected,306 cases(42.56%) were tested positive,including 239 cases of EV71 positive,and the EV positive rate of general cases(42.11%) was not statistic different from that(51.43%) of severe cases and dead cases(χ2=1.18,P =0.28),but there was statistic difference between the EV 71 positive rate of general cases(32.31%) with that(51.43%) of severe cases and dead cases(χ2=5.48,P =0.02).The EV positive rates of throat swab,Herpes fluid,anal swab,stool samples of clinically diagnosed cases with HFMD were high(all over 50%).10 EV strains were isolated from 59 stool samples including 7 strains of EV71,3 strains of CoxA16.【Conclusion】 HFMD cases can appear all over Hunan province and in each month,but higher period is from May to July.The mainly kind of etiology that causes HFMD is EV71 in Hunan province which could more easily cause severe HFMD and death.It accounts for 68.57% of the number of positive cases.All cities(prefecture) of Hunan province except for Zhuzhou city and Xiangxi Autonomous Prefecture have HFMD caused by EV71.Throat swab,Herpes fluid,anal swab or stool samples of clinically diagnosed cases with HFMD are sensitive samples for laboratory diagnosis.