Modification effects of socioeconomic factors on associations between air pollutants and hand, foot, and mouth disease: A multicity time-series study based on heavily polluted areas in the basin area of Sichuan Province, China

Abstract

Background Hand, foot, and mouth disease (HFMD) is a serious threat among children in China. Some studies have found that air pollution is associated with HFMD incidence, but the results showed heterogeneity. In this study, we aimed to explore the heterogeneity of associations between air pollutants and the number of HFMD cases and to identify significant socioeconomic effect modifiers. Methods We collected daily surveillance data on HFMD cases in those aged less than 15 years, air pollution variables and meteorological variables from 2015 to 2017 in the basin area of Sichuan Province. We also collected socioeconomic indicator data. We conducted a two-stage multicity time-series analysis. In the first stage, we constructed a distributed lag nonlinear model (DLNM) to obtain cumulative exposure-response curves between each air pollutant and the numbers of HFMD cases for every city. In the second stage, we carried out a multivariable meta-regression to merge the estimations in the first stage and to identify significant socioeconomic effect modifiers. Results We found that PM10, NO2 and O3 concentrations were associated with the number of HFMD cases. An inverted V-shaped association between PM10 and the number of HFMD cases was observed. The overall NO2-HFMD association was a hockey-stick shape. For the relationships of PM10, SO2, NO2, O3 and CO with HFMD counts, approximately 58.5%, 48.4%, 51.0%, 55.6% and 52.5% of the heterogeneity could be explained, respectively. The proportion of primary school students, population density, urbanization rate, number of licensed physicians and number of hospital beds explained part of the heterogeneity and modified the relationships. Conclusion Our study explored the heterogeneity of associations between air pollutants and HFMD counts. The proportion of primary school students, population density, urbanization rate, number of licensed physicians and number of hospital beds could modify the relationships. The results can serve as a reference for relevant public health decision making.

Risk effects of meteorological factors on human brucellosis in Jilin province, China, 2005–2019

“…However, our study has certain limitations. Although monitoring data can better reflect the nonlinear relationship between meteorological factors and infectious diseases [ 46 , 47 ], improving the accuracy of time series models requires research based on large amounts of data [ 48 ]. In addition, extreme weather conditions such as haze and dust storms have a great impact on the spread of infectious diseases, and it may be possible to add meteorological parameters related to air pollution to the model to more comprehensively and accurately investigate the impact of meteorological factors on the spread of brucellosis.…”

Risk effects of meteorological factors on human brucellosis in Jilin province, China, 2005-2019

“…However, our study has certain limitations. Although monitoring data can better re ect the nonlinear relationship between meteorological factors and infectious diseases (Brownstein et al 2010;Li et al 2022), improving the accuracy of time series models requires research based on large amounts of data (Shumway et al 2017). Although our study involved 15 years of data, the total data is still small because brucellosis is a monthly reported category B infectious disease in China.…”

The non-stationary and spatially varying associations between hand, foot and mouth disease and multiple environmental factors: A Bayesian spatiotemporal mapping model study

“…However, at the same time, this process will also improve the local public health condition and optimize the allocation of medical resources. Therefore, in some cases, the risk of HFMD appears relatively low in areas with convenient transportation and commercial prosperity, which can be observed in the distribution patterns of other infectious diseases ( Lei et al., 2023 ; Li et al., 2022 , Li et al., 2022 ). In terms of human intervention, specific vaccination is the most effective means to curb the spread of HFMD.…”