Researchers are looking into a viral disease that bats can spread to horses and eventually could reach humans. Since this is fatal to humans, the potential for a new pandemic is extremely concerning.
Zoonotic Spillover
Zoonotic spillover is the process by which pathogens spread from animals to people, frequently by way of a middle host.
Many harmful human diseases, including Ebola and SARS, have emerged and spread as a result of this process.
The Hendra virus, an emerging disease that primarily affects Australian flying foxes, a group of large fruit bats, is one of these zoonotic pathogens.
Bats are a breeding ground for a wide variety of viruses because of their strong immune systems. Pathogens that come from these animals are now a growing public health threat.
Hendra Virus
Although the Hendra virus does not appear to cause any obvious symptoms in infected bats, it can be transmitted to horses, and the intermediate host, and cause a fatal illness.
After several horses died from the virus in Brisbane, Australia in the middle of the 1990s, according to the Centers for Disease Control and Prevention.
The virus can also spread from horses to people, in which case it may result in a serious or fatal infection.
According to data from the Australian health authorities, only a small number of people have contracted the Hendra virus to date, but four out of the seven infected individuals, the majority of whom were veterinary professionals, died.
Raina Plowright, a professor at the College of Veterinary Medicine - Cornell University, said that With a 57% mortality rate in humans, the Hendra virus has a devastating effect on those who are infected, their families, the veterinary as well as equine industries in affected regions, and the general public.
Plowright is one of the authors of the study.
Virus Spillover and Hunger
For the latest study conducted by Plowright and colleagues, they gathered and compiled information to show how flying foxes found in subtropical Australia were reacting to habitat loss and climatic changes.
They discovered that the spread of the virus from bats to horses may be influenced by changes in the climate and land use.
Plowright said that this study illustrates how pathogens enter human populations as a result of the interaction between climate change and habitat loss.
A link between the Hendra virus and starving bats was discovered by Plowright and her coworker Peggy Eby.
In 2011, Eby noticed that bats were starving during a significant number of spillover events.
Meanwhile, in bats starving after a cyclone in Australia's Northern Territory, Plowright had found high levels of the Hendra virus.
Impacts of Climate Change
The first source of spillover that the scientists identified came from newly formed small bat populations in agricultural areas.
The group came into existence following starvation episodes that were often preceded by mild to severe El Niño events.
The researchers then put various theories about the relationships between the bats, environment, and spillover to the test using Bayesian network models.
The analysis revealed that bats were forced to live in urban and agricultural areas due to changes in land use and the climate.
Due to habitat loss brought on by the clearing of forests to make way for agriculture, among other things, many species of flying fox are in decline.
Habitat Restoration Benefits
The loss of natural habitats for bats also caused them to roost closer to populated areas, increasing the risk of Hendra spreading to horses, the researchers discovered.
Plowright explained that the models revealed that when no winter habitat produced food (nectar), bats in agricultural areas posed the highest risk of spillover.
Bats merged back into sizable nomadic populations and resumed feeding in their natural habitat when the last remaining winter habitat began to produce nectar.
The likelihood of spillover from any subtropical roost at the time this occurred was almost nonexistent.
The researchers discovered that restoring the bats' winter habitat and protecting what's left of it could be a way to stop spillover.
Read also: Monkeypox Cases Detected in Animals Might be Impossible to Control, Scientists Warn
Possibilities of Another Pandemic
Although the Hendra virus is unlikely to cause a pandemic, viruses similar to it are spread by bats in regions of the world where the environment is rapidly changing.
Hendra is a member of the henipavirus family, which also includes well-known viruses like the Nipah virus, which spreads to Bangladesh and India and has a 50% to 100% mortality rate among humans.
Plowright said that these viruses have the potential to become pandemic threats if they are not identified and detected.
A global catastrophe caused by the spread of such a virus would be far worse than COVID.
She added that their research highlights the significance of learning how these viruses' hosts-bats or other vertebrates-respond to habitat loss and climate change.
The Hendra virus study demonstrated how the loss of habitat can result in an increase in wild animal contact with humans and an increase in the viral excretion from those animals, Newsweek reported.
The study by Plowright, Eby and their colleagues was published on Wednesday in the journal Nature.
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