Climate change, its impact on emerging infectious diseases and new technologies to combat the challenge

Abstract

ABSTRACTImproved sanitation, increased access to health care, and advances in preventive and clinical medicine have reduced the mortality and morbidity rates of several infectious diseases. However, recent outbreaks of several emerging infectious diseases (EIDs) have caused substantial mortality and morbidity, and the frequency of these outbreaks is likely to increase due to pathogen, environmental, and population effects driven by climate change. Extreme or persistent changes in temperature, precipitation, humidity, and air pollution associated with climate change can, for example, expand the size of EID reservoirs, increase host-pathogen and cross-species host contacts to promote transmission or spillover events, and degrade the overall health of susceptible host populations leading to new EID outbreaks. It is therefore vital to establish global strategies to track and model potential responses of candidate EIDs to project their future behaviour and guide research efforts on early detection and diagnosis technologies and vaccine development efforts for these targets. Multi-disciplinary collaborations are demanding to develop effective inter-continental surveillance and modelling platforms that employ artificial intelligence to mitigate climate change effects on EID outbreaks. In this review, we discuss how climate change has increased the risk of EIDs and describe novel approaches to improve surveillance of emerging pathogens that pose the risk for EID outbreaks, new and existing measures that could be used to contain or reduce the risk of future EID outbreaks, and new methods to improve EID tracking during further outbreaks to limit disease transmission.

Keywords: Emerging infectious disease; climate change; early diagnosis; outbreak; transmission.

Figure 1.

Major EID outbreaks in the past 20 years demonstrating de novo jumps into human populations or increased geographic range or infectivity: A, timeline of emerging or re-emerging epidemic or endemic microbial infections. B, total estimated infected cases and C, deaths from major EID epidemics between 2003 and 2023. D, weekly confirmed deaths refer to the cumulative number of confirmed deaths over the previous week of Covid-19 since Jan 2020. E-G, leading EIDs with estimated total infected cases (E), newly infected cases (F) and deaths (G) in the latest report year (tuberculosis, 2022; malaria, 2021; hepatitis B, 2019; hepatitis C, 2019; HIV, 2022)(data sources GOV.UK, World Health Organization, US Centers for Disease Control and Prevention, European Centre for Disease Control and Prevention and OurWorldindata). Figure created with Biorender.com and Graphpad 9.4.1.

Figure 2.

The processes of pathogen spillover and EID outbreak: pathogens, including bacteria, virus, fungi, parasite and protozoan from wild animals move into domestic, pets, wild animals or directly to humans. This spillover process is further detailed in steps including long-term evolution of the pathogen itself to gain the ability to jump from the original reservoir host to intermediate host, formation of cyclic vector-host-vector transmission cycle and the population-based transmission after initial exposure event, and expansion of the pathogen’s geographical range beyond the region of spillover enabled by human-to-human transmission that leads to the EID outbreak. Figure created with Biorender.com.

Figure 3.

Environmental outcomes of climate change, potential climate-regulated mechanisms effects that can promote EID outbreaks, and measures that can be taken to prevent or limit EID transmission events. Figure created with Biorender.com.

Figure 4.

Multi-disciplinary, inter-continental and multi-platform-based approaches to prevent or contain EID, outbreaks, epidemics, and pandemics. Figure created with Biorender.com.