The effect of meteorological variables on the transmission of hand, foot and mouth disease in four major cities of shanxi province, China: a time series data analysis (2009-2013)

Abstract

Increased incidence of hand, foot and mouth disease (HFMD) has been recognized as a critical challenge to communicable disease control and public health response. This study aimed to quantify the association between climate variation and notified cases of HFMD in selected cities of Shanxi Province, and to provide evidence for disease control and prevention. Meteorological variables and HFMD cases data in 4 major cities (Datong, Taiyuan, Changzhi and Yuncheng) of Shanxi province, China, were obtained from the China Meteorology Administration and China CDC respectively over the period 1 January 2009 to 31 December 2013. Correlations analyses and Seasonal Autoregressive Integrated Moving Average (SARIMA) models were used to identify and quantify the relationship between the meteorological variables and HFMD. HFMD incidence varied seasonally with the majority of cases in the 4 cities occurring from May to July. Temperatures could play important roles in the incidence of HFMD in these regions. The SARIMA models indicate that a 1° C rise in average, maximum and minimum temperatures may lead to a similar relative increase in the number of cases in the 4 cities. The lag times for the effects of temperatures were identified in Taiyuan, Changzhi and Yuncheng. The numbers of cases were positively associated with average and minimum temperatures at a lag of 1 week in Taiyuan, Changzhi and Yuncheng, and with maximum temperature at a lag of 2 weeks in Yuncheng. Positive association between the temperature and HFMD has been identified from the 4 cities in Shanxi Province, although the role of weather variables on the transmission of HFMD varied in the 4 cities. Relevant prevention measures and public health action are required to reduce future risks of climate change with consideration of local climatic conditions.

Fig 1. Locations of study areas in Shanxi, China.

A, B, C, D: Datong, Taiyuan, Changzhi and Yuncheng, respectively.

Fig 2. Notified weekly cases of hand-foot-mouth disease (HFMD) and autocorrelation function (ACF) and Partial ACF (PACF) plot of original number of HFMD cases in 4 cities, Shanxi, 2009–2013.

A and E: the number of HFMD cases, ACF and PACF plots of Datong. B and F: the number of HFMD cases, ACF and PACF plots of Taiyuan. C and G: the number of HFMD cases, ACF and PACF plots of Changzhi. D and H: the number of HFMD cases, ACF and PACF plots of Yuncheng.

Fig 3. ACF and PACF plots of integrated the number of HFMD cases.

A, B, C and D show ACF and PACF plots for Datong, Taiyuan, Changzhi and Yuncheng.

Fig 4. ACF and PACF plots of residuals after applying the appropriate SARIMA model.

A: ACF and PACF plot of residuals of SARIMA (0,1,1)(2,0,1)₅₂ model for Datong. B: ACF and PACF plot of residuals of SARIMA (2,1,3)(1,1,1)₅₂ model for Taiyuan. C: ACF and PACF plot of residuals of SARIMA (0,1,1)(0,1,1)₅₂ model for Changzhi. D: ACF and PACF plot of residuals of SARIMA (0,1,1)(1,1,2)₅₂ model for Yuncheng.

Fig 5. Prediction of the number of HFMD cases on the basis of the model without and with weather variables.

A, B, C, D: Datong, Taiyuan, Changzhi and Yuncheng, respectively.

Fig 6. Dose-response curves of temperature with HFMD occurrence in 4 cities along lags.

The Y axes represent the relative risk (RR) for HFMD within a certain range of temperatures; the grey-shaded areas are 95% CIs. A, B, C, D: Datong, Taiyuan, Changzhi and Yuncheng, respectively.