Surveillance of hand foot and mouth disease in China, 2011-2012

Objective To understand the epidemiology characteristics of hand foot and mouth disease (HFMD) and risk factors for severe cases in China during 2011-2012. Methods The descriptive epidemiological analysis was conducted on the incidence data of HFMD in China during this period, which were collected from national disease reporting information system, with software SAS 9.2 and the data from 6th national population census were also used to understand its attack rate, case severity rate (CSR), case fatality rate (CFR) and severe case fatality rate (SCFR) and pathogen constituent. And the effects of potential risk factors were evaluated with unconditional logistic regression models. Results During 2011-2012, the attack rate of HFMD in China was 138.60/lakh, the CSR was 10.50, the CFR was 0.29 and the SCFR was 27.23. The cases, severe cases and deaths occurred during May-July accounted for 49.90%, 57.19% and 53.88% of the total respectively. The attack rate was highest in southern region (330.95/lakh), the CSR was highest in central region (18.62) and the CFR and SCFR were highest in southwestern region (0.71,45.72). The risks of severe case and death declined with age significantly. The risks of severe case and death in age group 0 year was 4.1 times (OR=4.10,95%CI:3.16-5.31) and 12.93 times (OR=12.93,95%CI=1.81-92.36) higher than those in age group 10 years. The risk of severe case and death after EV71 infection were 1.77 times (OR=2.77, 95%CI=2.65-2.89) and 10.04 times (OR=11.04, 95% CI=7.62-16.02) higher than those after other enteric virus infection. Conclusion HFMD mainly occurred during summer. The CSR was highest in central region and the CFR and SCFR were highest in southwestern region. Sever cases and deaths were prone to occur in young children and EV71 infected people.