Epidemiological characteristics and temporal-spatial clustering analysis of hand, foot and mouth disease in Nanchang city 2008-2012

Objective: To describe the epidemiological characteristics of hand, foot and mouth disease (HFMD) in Nanchang city during 2008-2012 and to detect potential temporal-spatial clusters. Methods: Data on HFMD in Nanchang City during 2008-2012 were derived from the National Notifiable Infectious Disease Reporting System (NNIDRS). We used descriptive methods to describe the epidemiological characteristics of HFMD. Space-time scan statistic, based on the Space-Time Permutation model, was adopted to determine the presence of space-time interaction clusters of HFMD in Nanchang. Results: There were 29 062 HFMD cases reported in Nanchang during 2008-2012. The annual average incidence rate was 118.56 per 100 000 inhabitants. There were two peaks in HFMD occurrence. Children aged 0-5 years accounted for 92.91% of cases. Scattered children (children not in nursery or kindergarten) accounted for 73.72%. There was a male predominance, with a male-to-female ratio of 1.82:1. Three space-time interaction clusters were explored including one most likely cluster and two secondary clusters from 2008 to 2012. Conclusions: Males and preschool children, especially in the 0-5-year age group, were more susceptible to HFMD and we should take measures to control their vulnerability. There were two peaks in HFMD occurrence, one during the summer (between April and July) and one in the autumn (between September and December). Northwest, middle east, and north Nanchang were the spatial-temporal clusters, so future public health planning and resource allocation should be focused on these areas.