Deciphering the impact of heat wave in the global surge of infectious diseases

The heat wave is the extreme episodes of climate change which is characterized as prolong period of abnormally elevated environmental temperatures other than the usual weather trends. In recent, the record-breaking environmental temperatures were observed all over the world, especially in the South Asia, Africa, and also in American countries. In Europe, over 70,000 additional deaths have been attributed to heat waves alone in 2022. This extreme climatic event has the implication to health risks and the potential rise in infectious diseases. This review establishes the multifaceted relationship between heat waves and infectious disease dynamics by the integration of existing literature and the emerging evidence from epidemiological, environmental, and laboratory studies. Heat waves create environments that favour the survival and propagation of various pathogens, including viruses, bacteria, protozoa, and fungi, thereby accelerate the speed of microbial biodiversity and evolutionary processes of microbes by progressively altering the ecosystem structures. Heat waves enhance the activity and distribution of insect vectors, leading to higher transmission rates of vector-borne sicknesses like dengue fever, chikungunya, malaria, Zika virus, Lyme disease and West Nile fever etc. Heatwave also could have the correlation to emerging antimicrobial resistance and pathogenic infections. Moreover, human behavioural changes during heat waves, may elevate the risk of food, air and waterborne diseases. However, the review provides a comprehensive understanding of how heat waves influence infectious disease dynamics. This review also emphasizes the need for interdisciplinary research, improved disease surveillance, and globally coordinated climate-health strategies to mitigate the risks.