Risk factors of hand, foot, and mouth disease in Guangzhou city, 2010 – 2014: a Bayesian fine-scale spatio-temporal modeling analysis

  Objective  To examine incidence characteristics and the risk factors of hand, foot, and mouth disease (HFMD) in Guangzhou city, Guangdong province, and to provide evidences for prevention and control of the disease.

  Methods  Data on reported HFMD incidences in Gurangzhou city from January 2010 through 2014 were collected from National Information System for Disease Control and Prevention; relevant socio-economic and meteorological data for the period were also retrieved. Descriptive statistics were performed to describe the incidence characteristics and Bayesian spatio-temporal model was applied to explore risk factors of the disease.

  Results  During the 5-year in the city, totally 289 216 HFMD incidents were reported, with the yearly case number (incidence rate) of 35 416 (319.53/100 000), 46 277 (364.36/100 000), 55 015 (431.44/100 000), 71 905 (560.05/100 000), and 80 603 (626.23/100 000) in 2010, 2011, 2012, 2013, and 2014, respectively, and a significantly increasing trend (χ² = 17 406.20, P < 0.001) . In the period, the HFMD incidence rate was significantly higher among the male residents than among the female residents (556.60/100 000 vs. 364.58/100 000; χ² = 12 383.86, P < 0.001) . The age-specific incidence rate was the highest for children aged ≤ 5 years and the HFMD cases of the age group accounted for 95.06% of the all the cases, of which, 74.80% were scattered living children. An obvious increase in reported HFMD incidents and two seasonal epidemic peaks from April to July and from September to October in a year were observed. The incidence rate was higher in urban-rural fringe zones, residential areas of with more migrant people, and outer suburbs, and 6 communities with much higher incidence rate were identified in these areas. The results of Bayesian spatio-temporal model analysis indicated that the increases in the number of urban village and the amount gross domestic production (GDP) per capita were risk factors of HFMD incidence in Guangzhou city, with the posterior median of relative risk of 2.657 (95% confidence interval 95% CI: 2.019 – 3.481) and 1.012 (95% CI: 1.007 – 1.017) ; while, the increases in the average weekly temperature and the number of bus station were protective factors against HFMD, and with the posterior median of relative risk of 0.995 (95% CI: 0.993 – 0.997) and 0.996 (95% CI: 0.995 – 0.997), respectively.

  Conclusion  The proportion of urban village, GDP per capita, average weekly temperature, and the number of bus station are main impact factors for HFMD epidemic and comprehensive countermeasures should be taken to control the incidence of the disease in Guangzhou city.