The Potential Impact of Climate Change on Infectious Disease

A new review in the journal Infectious Diseases of Poverty takes a look at papers examining the effect climate change will have on infectious diseases.

No matter who you are or where you are from, it’s almost inevitable that climate change will have a major impact on your life. Whether it be rising sea levels or changes in food production, it threatens to upend our lives and ecosystems. It can even affect which diseases you could be at risk for in your region.

This is because many vectors, especially cold-blooded ones, are better able to spread in warmer climates. Thus, as temperatures rise, it is likely that vectors such as mosquitos and ticks will be able to travel farther north and also be active for longer period of time during the year, which in turn means an increase in the number of vector-borne diseases, such as malaria and dengue fever, in both humans and animals. A study published in PLOS Neglected Tropical Diseases estimates that by 2050, the number of people at risk for diseases transmitted by two species of mosquitos, Aedes albopictus and A. aegypti, could increase by half a billion.

However, it’s also possible that certain vectors will disappear from areas where they are currently endemic. Lab experiments have shown that A. aegypti larva die when water temperature surpasses 34°C, as will adults when the air hits 40°C. It is therefore imperative to study the potential impact climate change could have on diseases, both those which are vector-borne and those which are not, as well as how best to mitigate the spread.

In a new Scoping Review published in Infectious Diseases of Poverty, Van de Vuurst and Escobar examined the recent research trends in studies looking at infectious diseases and climate change, as well as gaps in the literature. To do this, they searched the PubMed repository as well as Clarivate’s Web of Science database using keywords such as “climate change,” “disease,” “vector borne,” “parasite,” and more. The time frame was set to the beginning of 2015 until the end of 2020, and only peer-reviewed research articles were included (so publications like book chapters and reviews were not a part of the search).

In total, the authors identified 621 relevant articles. They then analyzed these in a number of ways, including looking at the topics studied, the geographic distribution of authors, funding, and even the preferred pronouns of the first and senior authors (those who identified as “he/him” represented the greatest percentage). They found that most of the research focused on zoonotic diseases in developed countries like Australia, Canada, China, the UK, and the US. This therefore points to a need for more studies in tropical regions, as well as for more investigations into the effects climate change could potentially have on non-vector-borne diseases.

Additionally, Van de Vuurst and Escobar found that many of these papers focused on humans. While understandable, given that it was, well, humans who authored them, it’s still vital to study the impact climate change may have on infectious diseases in both farm animals and wildlife. As rising temperatures threaten ecosystems, it is important to investigate diseases that may offset the ecological balance even more. This review therefore points to important gaps in the scientific literature that should be better studied so that we can better understand the many effects of climate change.

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