This article was originally KHN.
More than 40 Jamaican flying foxes will be transported to a laboratory in Bozeman, Montana, to be part of an experiment with the ambitious goal of predicting the next pandemic.
Worldwide, bats are the primary vectors for virus transmission from animals to humans. These viruses are often harmless to bats but can be deadly to humans. For example, horseshoe crabs in China have been cited as a possible cause of the covid-19 outbreak. Researchers also believe that the pressure on bats from climate change and encroachment from human development has increased the frequency at which viruses are transmitted from bats to humans, causing diseases known as zoonotic diseases. .
“The spillover phenomenon is the result of a series of stressors: bat habitats are wiped out, climate becomes more extreme, and bats migrate into human settlements in search of food.” journal nature and another ecology letter On the role of ecological change in disease.
So Agnieszka Rynda-Apple, an immunologist at Montana State University, brought Jamaican flying foxes to Bozeman this winter to start a breeding colony and work in the lab as part of a team of 70 researchers from seven countries. We are planning to accelerate the work. The group, called BatOneHealth, founded by Plowright, wants to find a way to predict where the next deadly virus might make the leap from bats to humans.
Rynda-Apple says: “We’re trying to understand what makes their immune system retain the virus and under what circumstances it sheds it.”
To study the role of nutritional stress, the researchers created different diets for them, “infected them with the influenza virus, and examined the amount of virus they shed, the length of viral shedding, and the antiviral response.” ‘ she said.
She and her colleagues are already doing this kind of experiment, but breeding bats could expand their research.
Fully understanding how environmental changes contribute to nutritional stress and predicting spillover more accurately is a daunting endeavor. It gives us a tool to think about eco-measures that we can implement in our environment,” says Associate Professor Andrew Hogue. of his MSU statistics modeling possible spillover scenarios.
A small team of researchers at MSU is collaborating with researchers at the National Institutes of Health’s Rocky Mountain Laboratory in Hamilton, Montana.
A recent paper in Nature and Ecology Letters focuses on the Australian Hendra virus from which Plowright originated.Hendra is a respiratory virus that causes flu-like symptoms, is transmitted from bats to horses, and can then be passed on to people who treat horses. 75% in horsesOf the seven confirmed cases, four have died.
The question that drove Plowright’s research was why Hendra began appearing in horses and humans in the 1990s, even though bats have likely hosted the virus for a long time. Studies show that the reason is environmental change.
Plowright began researching bats in 2006. In samples she took from an Australian bat called the flying fox, she and her colleagues detected very little virus. From 2005 to 2006, hundreds of thousands of bats disappeared after Cyclone Her Rally off her northern territory wiped out the bats’ food sources. But they found a small population of weak, starving bats loaded with the Hendra virus.
She and her collaborators combed through 25 years of data on habitat loss, spillovers and climate and found a link between food source loss due to environmental change and high viral load in food-stressed bats. Did.
next year El Nino Hot weather patterns that occur every few years prevent many eucalyptus trees from producing the nectar-laden flowers that bats need. Alternate food sources are also being lost due to human encroachment on other habitats, from farms to urban development. As such, bats tend to migrate to substandard figs, mangoes, and other wooded urban areas, where they shed the virus when stressed. When bats excrete urine or feces, horses smell the ground and inhale it.
Researchers say studies using Hendra-infected bats illustrate universal principles of how the destruction and alteration of nature increases the chances of deadly pathogens escaping from wild animals to humans. I hope to
The three most likely sources of spillovers are bats, mammals and arthropods, especially mites.Several 60% of emerging infectious diseases Pathogens that infect humans are of animal origin, about two-thirds of which come from wild animals.
The idea that deforestation and human encroachment on wild lands contribute to pandemics is not new. For example, experts believe that HIV, which causes AIDS, was first transmitted to humans in Central Africa when people ate chimpanzees. In late 1998-early 1999, a bat-borne Nipah virus outbreak in Malaysia spread from bats to pigs. Pigs amplified it and it spread to humans, infecting 276 people and killing 106 of him in the outbreak. Currently, links to stress induced by environmental changes are emerging.
One of the key pieces to this complex puzzle is the bat’s immune system. Jamaican fruit bats housed at the MSU will help researchers learn more about the effects of nutritional stress on viral load.
BatOneHealth member Vincent Munster, head of the Rocky Mountain Institute’s Viral Ecology Division, is also looking to different species of bats to better understand the ecology of spillovers. “There are 1,400 different species of bats, and there is a huge difference between bats that carry the coronavirus and bats that carry the Ebola virus,” said Münster. “And bats that live with hundreds of thousands of bats, and bats that are relatively solitary.”
Meanwhile, Plowright’s husband, Gary Tabor, is president of the Center for Large Landscape Conservation, a non-profit organization that applies the ecology of disease research to protect wildlife habitat. increase.
“Habitat fragmentation is a poorly addressed planetary health issue given that the world continues to experience unprecedented levels of land clearing,” Tabor said.
As our ability to predict outbreaks improves, other strategies become possible. Models that can predict where Hendra virus will flow could lead to vaccination of horses in those areas.
Another possible solution is the set of “green measures” mentioned by Hoegh. For example, large-scale planting of flowering eucalyptus trees to discourage fruit bats from seeking nectar in developed areas.
“Right now, the world is focused on how we can stop the next pandemic,” said Plowright. “Unfortunately, preserving or restoring nature is rarely discussed.”
KHN (Kaiser Health News) is a national newsroom that produces in-depth journalism on health issues. KHN is one of his three major operational programs in the United States, along with policy analysis and polling KFFMore (Kaiser Family Foundation). KFF is a donated non-profit organization that provides information on health issues to the public.
