Scientists in Australia have identified an animal they suspect could be the source of the next big viral pandemic: flying foxes, also known as “megabats”. The flying mammals, which have a wingspan of three feet, tend to shed the virus when they are hungry, a time when they venture close to humans and farm animals, Telegraph reported. The scenario increases the chance of propagation events when viruses jump from animals to humans or other animals.
Experts believe that the COVID pandemic began when the SARS-CoV-2 virus transferred from an animal to a human. In a recent study, scientists looked at the Hendra virus, a rare respiratory disease carried by bats. Animals have robust immune systems that allow them to carry various dangerous viruses without becoming infected, including SARS and Marburg. Hendra is particularly dangerous – it kills 75% of horses that contract it and can also infect humans. Read on to learn more.
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Propagation events reported
Hendra virus was first identified in Australia in 1994. In the first outbreak, two people contracted Hendra from horses. One, a stable, recovered; another, a 49-year-old horse trainer, died. In horses, Hendra symptoms include runny nose, fever, difficulty breathing and neurological problems such as compulsive drinking of water or hitting their stalls.
Since then, Hendra has moved from bats to horses in about 60 propagation events and infected seven people, killing four, Telegraph reported.
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Hungry bats spread more virus
Megalilies live mainly on the nectar of eucalyptus flowers. Scientists say most Hendra outbreaks occurred after these flowers were absent; no spillover events were reported when flowers were abundant. In years when there was a shortage of nectar, the bats appeared to carry higher levels of the virus. This is probably because their immune systems were exhausted and less able to keep the virus under control.
“We can hypothesize that among mammals, animals that are nutritionally stressed are less able to control viruses and therefore more likely to shed viruses,” said Raina Plowright, an infectious disease ecologist at the University of Cornell. Telegraph.
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People, approaching bats
Unfortunately, climate change and industrialization are encroaching on the bats’ food source. There are fewer trees and fewer flowers. This pushed megabats closer to humans and animals in search of food. “Strategies that make sure animals have enough to eat, have enough habits so they’re not stressed, and so they can move through their environment without having to overlap with humans all contribute to reducing the risk of runoff.” , Plowright said. Telegraph. She noted that other bat viruses are also a concern, including Nipah, a disease that is 70 percent fatal.
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The study of viruses needed before they reach humans
Scientists need to do more to study how viruses spread within animal populations before reaching humans, Plowright said. “Usually we only focus on the virus, and usually only after it spreads in the human population,” she said. “We rarely work backwards to figure out where the virus came from and why it evolved from a wild species into humans,” she said.
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The ecology of the hosts is the key
“If we understand the ecology of the reservoir hosts – the food they need at different times of the year and when food is available or removed, then we can study those times and places where all the stressors line up,” Plowright added.