Association between meteorological factors and COVID-19 transmission in low- and middle-income countries: A time-stratified case-crossover study

Yu Wang; Yiran Lyu; Shilu Tong; Cheng Ding; Lan Wei; Mengying Zhai; Kaiqiang Xu; Ruiting Hao; Xiaochen Wang; Na Li; Yueyun Luo; Yonghong Li; Jiao Wang

doi:10.1016/j.envres.2023.116088

Association between meteorological factors and COVID-19 transmission in low- and middle-income countries: A time-stratified case-crossover study

Environ Res. 2023 Aug 15;231(Pt 1):116088. doi: 10.1016/j.envres.2023.116088. Epub 2023 May 9.

Authors

Yu Wang¹, Yiran Lyu¹, Shilu Tong², Cheng Ding¹, Lan Wei¹, Mengying Zhai¹, Kaiqiang Xu³, Ruiting Hao¹, Xiaochen Wang¹, Na Li¹, Yueyun Luo¹, Yonghong Li¹, Jiao Wang⁴

Affiliations

¹ China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China.
² China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China; Shanghai Children's Medical Center, Shanghai Jiao Tong University, Shanghai, 200025, China; School of Public Health, Institute of Environment and Population Health, Anhui Medical University, Hefei, 230032, China; Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China; School of Public Health and Social Work, Queensland University of Technology, Brisbane, 4000, Australia.
³ China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China; School of Public Health, Hebei University, Hebei, 071000, China.
⁴ China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China. Electronic address: wangjiao@nieh.chinacdc.cn.

Abstract

Background: Evidence is limited regarding the association between meteorological factors and COVID-19 transmission in low- and middle-income countries (LMICs).

Objective: To investigate the independent and interactive effects of temperature, relative humidity (RH), and ultraviolet (UV) radiation on the spread of COVID-19 in LMICs.

Methods: We collected daily data on COVID-19 confirmed cases, meteorological factors and non-pharmaceutical interventions (NPIs) in 2143 city- and district-level sites from 6 LMICs during 2020. We applied a time-stratified case-crossover design with distributed lag nonlinear model to evaluate the independent and interactive effects of meteorological factors on COVID-19 transmission after controlling NPIs. We generated an overall estimate through pooling site-specific relative risks (RR) using a multivariate meta-regression model.

Results: There was a positive, non-linear, association between temperature and COVID-19 confirmed cases in all study sites, while RH and UV showed negative non-linear associations. RR of the 90th percentile temperature (28.1 °C) was 1.14 [95% confidence interval (CI): 1.02, 1.28] compared with the 50th percentile temperature (24.4 °C). RR of the10th percentile UV was 1.41 (95% CI: 1.29, 1.54). High temperature and high RH were associated with increased risks in temperate climate but decreased risks in tropical climate, while UV exhibited a consistent, negative association across climate zones. Temperature, RH, and UV interacted to affect COVID-19 transmission. Temperature and RH also showed higher risks in low NPIs sites.

Conclusion: Temperature, RH, and UV appeared to independently and interactively affect the transmission of COVID-19 in LMICs but such associations varied with climate zones. Our results suggest that more attention should be paid to meteorological variation when the transmission of COVID-19 is still rampant in LMICs.

Keywords: COVID-19; LMICs; Relative humidity; Temperature; Ultraviolet.

MeSH terms

COVID-19* / epidemiology
China
Cross-Over Studies
Developing Countries
Humans
Humidity
Meteorological Concepts
Temperature
Tropical Climate