CLIMATE CHANGE, ALTITUDE SHIFT AND VIRUS EMERGENCE: A REVIEW ON PTEROPUS BATS IN HIMALAYAN REGION

Abstract

The potential risk of new infectious diseases to global public health is significant, and climate change has been recognized as a key driver of zoonotic spillover events. The Nipah virus, which has the Pteropus bat (flying fox) as its natural host, is one such disease. The Himalayan region, a biodiversity hotspot and climate change-sensitive area, is a critically understudied region in terms of the ecology of Pteropus bats and the emergence of the Nipah virus. This review aims to compile the knowledge on the distribution and ecology of Pteropus bats in Himalayan region, analyze the expected impact of climate change on the altitudinal distribution of Pteropus bats, and discuss the expected implications of Nipah virus outbreaks. There is very little information available on the ecology of Pteropus bats in the Himalayan region, and only one species-specific distribution modeling study is available from Nepal. Contrary to the expected altitudinal migration pattern in mountainous regions, this study reveals that climate change is not expected to improve the altitudinal distribution of Pteropus medius. Instead, their suitable habitat is expected to be reduced and limited to lower-altitude regions due to their susceptibility to low temperatures. This predicted reduction of range size also overlaps with areas of high human population density and agricultural activity, which could increase the human-bat interface. Among the factors that could play a role in the potential increase in the risk of spillover are the increased viral shedding in the colony because of high population density, stress induced by the disruption of the phenology of fruit tree flowering because of climate change, and the increased opportunities for environmental contamination of date palm sap and food. The interaction of climate change, the unique altitudinal ecology of Pteropus bats, and high human population density in the Himalayan lowlands makes this area a potential perfect storm for the emergence of Nipah virus. A plan to meet this potential risk is to implement immediate, interdisciplinary One Health approaches that include wildlife surveillance, climate modeling, and ecological research to decrease the risk of spillover in this high-risk area.