Analysis of Etiology surveillance results of hand-foot-mouth disease cases in Hainan Province in 2010-2011

Objective To analyze the main virus types and their change trend which caused pandemic of Disease(HFMD)in Hainan province in 2010-2011 in order to provide the etiology basis for diagnosis of HFMD cases and carrying out the control measures of HFMD.Methods According to the Ministry of Health issued Hand-Foot-Mouth Disease Control and Prevention Guide,to treat and test specimens of HFMD.The RNA was amplified by real-time fluorescence PCR using the enterovirus universal primer,enterovirus type 71 primer and Coxsackie virus group A type 16 primer.The nucleic acids positive specimens were inoculated to RD cell lines to isolate enteroviruses.The representative virus strains were sequenced and analyzed.Results The infection rate of EV71 in HFMD severe cases in Hainan province in 2010 and 2011 was respectively 45.52% and 19.45%.The infection rate of CoxA16 was only 6.9% and 4.7%.But in HFMD common cases in Hainan province in 2010 and 2011,the infection rate of CoxA16 was respectively 19.63% and 24.8%,the infection rate of EV71 was 16.34% and 6.36%.The result of viruses sequence analysis showed that the main genotype were C4a of EV71,B1a and B1b of CoxA16 which caused pandemic of HFMD in Hainan province in 2010-2011.CoxA10,CoxA6 and CoxA4 also played important role.Some HFMD cases were caused by CoxA5、CoxB1、 CoxB2、ECHO 3 and ECHO 11.Most of HFMD severe cases in Hainan province were caused by EV71.Fewer severe cases were caused by CoxA16.The infection rates of CoxA16 was respectively 6.9% and 4.7% in HFMD severe cases in Hainan province in 2010 and 2011.However the proportion of HFMD severe cases which infected CoxA10 and CoxA6 was higher than that infected other type enterovirus,such as CoxA4.Conclusions The main pathogen was still EV71 in HFMD severe cases in Hainan province in 2010-2011.In the HFMD common cases the infection rate of EV71 was reduced.However the infection rate of CoxA16 was rising.Many pathogens of enterovirus were existed meantime at crowd in Hainan.So the morbidity of HFMD in Hainan was high and HFMD severe cases appeared continuously.Especially CoxA10 and CoxA6 usually cased HFMD severe cases.The further research in this field work was deserved.