Epidemiological Investigation Of Hand,Foot And Mouth Disease Children And Their Exposed Population In Hangzhou City,2013

Objective To compare the capabilities of different detection methods for hand-foot-and-mouth disease pathogens and analyze the differences in pathogen infection and laboratory examination between children with severe and mild HFMD. To investigate the changes of advantage pathogens of HFMD in recent years in Hangzhou city and survey the infection rates of the exposed population.Methods1. Throat swabs or feces and serum samples were collected from children suspected as HFMD, which were detected by both reverse transcription polymerase chain reaction (RT-PCR) and enzyme linked immunosorbent assay (ELISA). The differences of the detection rates of HFMD between the two methods were analyzed with χ tests.2. The specimens of849children suspected as HFMD were detected by RT-PCR. The distributions of the age, sex and clinical symptoms were described depending on the results.3. Cerebrospinal fluid specimens collected from EV71-severe group, non-EV71-severe group and EV-mild group were detected by biochemical tests, routine examinations, ELISA and RT-PCR.4. The HFMD-exposed population chosen from the family members of EV71-severe group were classified into the intimate group, the general group and the medical group. The virus infection rates of HFMD-exposed population in each group were calculated according to the RT-PCR results in feces. The chi square test was used to calculate the differences between the intimate group and the general group.Results1. There were no significant differences between RT-PCR and ELISA on the detection rates of EV71and CVA16.(P>0.05).2.641children were diagnosed with HFMD by enterovirus. The proportion of boys and girls was1.4to1, while80.3%were children1to3years old. Of the641HFMD children,150were severe and491were mild. The proportions of EV71, CVA16and other EV were24.3%,4.7%and71.0%respectively.3. The results of MT-P in the severe HFMD group were significantly higher than in the mild HFMD group (P<0.05). The increased cells in CSF were mainly neutrophils in the EV71-severe group, while lymphocytes were the mainly increased cells in both non-EV71-severe group and EV-mild group (P<0.05). The positive rates of the CSF specimens were69.1%in EV71-IgM (38/55) and0%in EV71-RNA.4. There were no significant differences between the intimate and general group (P>0.05).Conclusion1. It showed the similar detection abilities between RT-PCR and ELISA.2. EV71was the most important pathogen of causing severe HFMD in young children.3. The micro total protein and the type of increased karyocytes having significant differences between the severe and mild HFMD groups.4. The advantage pathogen causing HFMD in Hangzhou had transformed from EV71in2011and2012to non-EV71-CVA16enterovirus in2013.5. The enterovirus infectivity was no associated with the degree of intimacy, but was closely related with personal hygiene and protective equipments.