OBJECTIVETo investigate the epidemic characteristics of etiological agents in children with hand, foot and mouth disease (HFMD) and analyze the differences between the severe and mild cases with HFMD seen from 2008 to 2009 in the Children's Hospital.

METHODSA total of 154 patients with HFMD were enrolled from May 2008 to September 2008 and from May 2009 to September 2009, including 28 severe HFMD patients. Data from 80 cases with suspected herpangina were collected as control. Enterovirus universal type, enterovirus type 71 (EV71) and coxsackie virus group A 16 (CA16) were detected by real-time RT-PCR respectively.

RESULTSThe positive rate of enterovirus universal type in the 154 patients with HFMD was 81.82%(126/154). EV71 positive rate in these 126 patients with enterovirus universal type infection was 57.14%(72/126). The positive rate of enterovirus universal type in the 80 cases with suspected herpangina was 68.75%(55/80). There was no EV71 infection in these 80 cases with suspected herpangina. EV71 infection was mainly popular in 2008. Both EV71 and CA16 were prevalent in 2009. The epidemic characteristics of enterovirus infection with HFMD between 2008 and 2009 had significant differences (χ(2) = 23.50, P = 0.000) (P < 0.01). The epidemic characteristics of enterovirus infection between severe and mild HFMD patients also had significant differences (χ(2) = 29.85, P < 0.01). There were 28 cases with severe HFMD, in whom the EV71 positive rate was 92.86% (26/28). EV71 positive rate in the mild HFMD was 36.51% (46/126) (χ(2) = 29.22, P < 0.01). There was no significant difference in the gender (χ(2) = 0.135, P = 0.714) and virus load (t = 0.141, P = 0.889) between the mild and severe HFMD cases. But the age of mild and severe HFMD showed a significant difference (t = 2.926, P = 0.009). Patients who were less than 2 years of age had a proportion of 88.89% (8/9) with severe HFMD. The mean age of mild HFMD patients was 3.19 years.

CONCLUSIONHFMD showed different epidemic characteristics at different times of enterovirus infection. There was no significant difference in the gender and virus load between the mild and severe cases with HFMD. Children under 3 years of age with EV71 infection were at high risk for severe HFMD.