Exploring rural hospital admissions for diarrhoeal disease, malaria, pneumonia, and asthma in relation to temperature, rainfall and air pollution using wavelet transform analysis

Thandi Kapwata; Caradee Y Wright; David Jean du Preez; Zamantimande Kunene; Angela Mathee; Takayoshi Ikeda; Willem Landman; Rajendra Maharaj; Neville Sweijd; Noboru Minakawa; Suzana Blesic

doi:10.1016/j.scitotenv.2021.148307

Exploring rural hospital admissions for diarrhoeal disease, malaria, pneumonia, and asthma in relation to temperature, rainfall and air pollution using wavelet transform analysis

Sci Total Environ. 2021 Oct 15:791:148307. doi: 10.1016/j.scitotenv.2021.148307. Epub 2021 Jun 8.

Authors

Affiliations

¹ Environment and Health Research Unit, South African Medical Research Council, Johannesburg, South Africa; Environmental Health Department, Faculty of Health Sciences, University of Johannesburg, Johannesburg, South Africa.
² Environment and Health Research Unit, South African Medical Research Council, Pretoria, South Africa; Department of Geography, Geoinformatics and Meteorology, University of Pretoria, Pretoria, South Africa. Electronic address: Caradee.Wright@mrc.ac.za.
³ Department of Geography, Geoinformatics and Meteorology, University of Pretoria, Pretoria, South Africa; Laboratoire de l'Atmosphère et des Cyclones (UMR 8105 CNRS, Université de La Réunion, MétéoFrance), 97744 Saint-Denis de La Réunion, France.
⁴ Environment and Health Research Unit, South African Medical Research Council, Johannesburg, South Africa.
⁵ Environment and Health Research Unit, South African Medical Research Council, Johannesburg, South Africa; Environmental Health Department, Faculty of Health Sciences, University of Johannesburg, Johannesburg, South Africa; School of Public Health, University of the Witwatersrand, Johannesburg 2028, South Africa; Department of Environmental Health, Faculty of Health Sciences, Nelson Mandela University, Port Elizabeth, South Africa.
⁶ Blue Earth Security Co., Ltd., Chiyoda-ku, Tokyo, Japan.
⁷ Department of Geography, Geoinformatics and Meteorology, University of Pretoria, Pretoria, South Africa; International Research Institute for Climate and Society, The Earth Institute of Columbia University, New York, NY, 10964, USA.
⁸ Office of Malaria Research, South African Medical Research Council, Durban, South Africa.
⁹ Applied Centre for Climate and Earth Systems Science, National Research Foundation, Cape Town, South Africa.
¹⁰ Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
¹¹ Institute for Medical Research, University of Belgrade, Belgrade, Serbia; Center for Participatory Science, Belgrade, Serbia.

PMID: 34139502
DOI: 10.1016/j.scitotenv.2021.148307

Abstract

Background: Climate variables impact human health and in an era of climate change, there is a pressing need to understand these relationships to best inform how such impacts are likely to change.

Objectives: This study sought to investigate time series of daily admissions from two public hospitals in Limpopo province in South Africa with climate variability and air quality.

Methods: We used wavelet transform cross-correlation analysis to monitor coincidences in changes of meteorological (temperature and rainfall) and air quality (concentrations of PM_2.5 and NO₂) variables with admissions to hospitals for gastrointestinal illnesses including diarrhoea, pneumonia-related diagnosis, malaria and asthma cases. We were interested to disentangle meteorological or environmental variables that might be associated with underlying temporal variations of disease prevalence measured through visits to hospitals.

Results: We found preconditioning of prevalence of pneumonia by changes in air quality and showed that malaria in South Africa is a multivariate event, initiated by co-occurrence of heat and rainfall. We provided new statistical estimates of time delays between the change of weather or air pollution and increase of hospital admissions for pneumonia and malaria that are addition to already known seasonal variations. We found that increase of prevalence of pneumonia follows changes in air quality after a time period of 10 to 15 days, while the increase of incidence of malaria follows the co-occurrence of high temperature and rainfall after a 30-day interval.

Discussion: Our findings have relevance for early warning system development and climate change adaptation planning to protect human health and well-being.

Keywords: Climate change; Environmental health; Infectious disease; Respiratory disease.

MeSH terms

Air Pollution*
Asthma* / epidemiology
Diarrhea / epidemiology
Hospitals, Rural
Humans
Malaria* / epidemiology
Pneumonia* / epidemiology
Temperature
Wavelet Analysis