Climate change and infectious disease: a review of evidence and research trends

Abstract

Background: Climate change presents an imminent threat to almost all biological systems across the globe. In recent years there have been a series of studies showing how changes in climate can impact infectious disease transmission. Many of these publications focus on simulations based on in silico data, shadowing empirical research based on field and laboratory data. A synthesis work of empirical climate change and infectious disease research is still lacking.

Methods: We conducted a systemic review of research from 2015 to 2020 period on climate change and infectious diseases to identify major trends and current gaps of research. Literature was sourced from Web of Science and PubMed literary repositories using a key word search, and was reviewed using a delineated inclusion criteria by a team of reviewers.

Results: Our review revealed that both taxonomic and geographic biases are present in climate and infectious disease research, specifically with regard to types of disease transmission and localities studied. Empirical investigations on vector-borne diseases associated with mosquitoes comprised the majority of research on the climate change and infectious disease literature. Furthermore, demographic trends in the institutions and individuals published revealed research bias towards research conducted across temperate, high-income countries. We also identified key trends in funding sources for most resent literature and a discrepancy in the gender identities of publishing authors which may reflect current systemic inequities in the scientific field.

Conclusions: Future research lines on climate change and infectious diseases should considered diseases of direct transmission (non-vector-borne) and more research effort in the tropics. Inclusion of local research in low- and middle-income countries was generally neglected. Research on climate change and infectious disease has failed to be socially inclusive, geographically balanced, and broad in terms of the disease systems studied, limiting our capacities to better understand the actual effects of climate change on health.

Keywords: Climate change; Infectious disease; Research trend; Systematic review.

Fig. 1

Trends in climate change and disease research. Number of publications (x-axis) from 2015–2020 according to A taxa of host species studied, B transmission type of diseases studied, C vector species studied, and D top 20 most studied diseases from over 100 different diseases studied. Multiple: multiple diseases with multiple transmission types studied in a single article

Fig. 2

Bibliometric demographics. A Number of publications (x-axis) from 2015–2020 when delimited by scale of study. N/A: Studies for which a spatial scale was not applicable (e.g., laboratory-based studies) or for which scale was not specified. B Percentile breakdown of lead author affiliations collated into categories based on the institution’s description (i.e., college or university, governmental organizations or research organization). Other: lead author affiliation institutions which do not fit one of these categories including non-governmental organizations, independent researchers, or private companies not otherwise specified

Fig. 3

Author pronouns on climate change and infectious disease research. The self-identified pronouns of A first authors and B last (senior) authors of articles on climate change and disease from 2015 to 2020. The disparity between he/him pronoun usage over other pronouns was pronounced for senior authors. Authors’ pronoun usage in public settings may vary from their gender identities

Fig. 4

Map of study locations by country. A The geographic representation of where studies were conducted (i.e., country where the data analyzed in the study originated) from 2015–2020 on climate change and infectious disease and B publications that fit the inclusion criteria as a proportion of human population in 2020 (per one million individuals). Population data were collected from the United Nations Population Division [26]. Darker color represents more publications conducted in or on the corresponding country. Grey indicates that no studies which fit the inclusion criteria were conducted in or on the corresponding countries. Shape file for map creation sourced from DIVA-GIS [84, 85]

Fig. 5

Map of lead author affiliation origins. The geographic representation of lead author affiliation origins for research on climate change and disease from 2015 to 2020. Darker color represents more publications originating from the corresponding country. Grey indicates that no studies which fit the inclusion criteria were conducted by authors affiliated with the corresponding countries. Blue points indicate the top ten publishing institutions globally for climate change and disease. Shape file for map creation sourced from DIVA-GIS [84, 85]