For more than 50 years, Latin American countries have killed vampire bats to curb the spread of rabies. These flying vampires are common hosts of disease-causing viruses that kill and cost hundreds of cattle each year. Estimated $170,000 It damages local farmers in southern Peru every year.
Anti-vampire agents are used to kill wildlife. This lethal venom spreads to up to 15 bats per animal treated. But he has one problem that humans have not been able to explain.
“The intervention was well-intentioned to control the infection, but it backfired because we didn’t understand how the animals would respond,” he said. Daniel Strykerprofessor of viral ecology at the University of Glasgow and senior author of a new study published today scientific progressInstead of slowing the progression of rabies, culling in areas with high circulation of the virus caused bats to fly more frequently across landscapes, accelerating the spread of the disease.
it’s all a matter of timing
The authors of the study first studied how culling affects bat populations and then the risk of transmitting rabies to livestock in large areas of southern Peru. Although culling reduced bat populations, it didn’t stop the hungry biters entirely. About 59% of farms in the area report that he had at least one animal bitten by a vampire bat three months after he was exterminated.
The team also examined how culling affects the circulation of the rabies virus. By sequencing the viral genome sequence, we reconstructed how the virus spread across the landscape through space and time.
Culling affected how quickly the virus spread. Viruses seem to spread faster if culling takes place in areas where virus circulation is active. It seems that he flew away to avoid death. This makes bats more likely to carry the virus over long distances.
But in areas without recent rabies outbreaks, the virus takes more time to spread. Our findings suggest that it all comes down to context. Aggressive culling in an area before the virus arrives may slow its spread to new areas and prolong rabies-free areas. “I can’t say that rabies never happens, but it probably happens more slowly,” he says, Streicker.
Is culling the only strategy?
Vaccination is an alternative means of controlling rabies, but Steicker said people in Latin America have historically been reluctant to vaccinate. People often get the rabies vaccine after being exposed to the virus, but this is less effective. Another problem is that vaccine delivery has become difficult in some remote areas of Latin America.
Vaccination of livestock is another option for controlling rabies transmission. However, vaccinating all animals is costly for farmers, especially those living in areas with little or no rabies problem.
Some locals set fire to roosters to destroy potentially diseased birds, or cut down trees that might harbor other rabies-infected creatures to save themselves. However, the researchers do not recommend these methods because they can harm animals that are not infected with the virus.
Other ways to slow rabies
Vampire bats are not the only bat species that transmit rabies, but they may be the primary rabies vector. These vampires have to eat almost every night, putting the victim at a higher risk of contracting rabies. Grazing cattle and other livestock also provided bats with an almost limitless food source, Stryker said.
Instead of vaccinating humans and cattle, One approach is Researching a vampire bat vaccine. Vaccinating bats is not easy. They are reclusive wild animals and nearly impossible to catch individually. Successful rabies vaccines require delivery techniques to reach sufficient numbers of wild animals. Steicker and his team are now self-seeding vaccine that they administer to one bat. From there, the vaccine can spread on its own to other bats.
Another approach is reproductive suppression, in which bats consume blood containing coumestrol, an organic compound that acts as a bat. contraception. in progress research suggested that coumestrol affects the fertility and population decline of male and female vampire bats. Ultimately, controlling rabies in bat populations will require all three strategies, he said: vaccination, reproductive suppression, and preventive culling in areas where the virus has not yet reached. said.
