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Posted 12 months ago
Bat Virus Kills Boy: Will the Public Panic?
But conservationists fear an overreaction to the news may result in the wholesale slaughter of an animal that performs an important ecological role.
The boy died after being bitten by a bat while vacationing in the northeastern state of Queensland. The bat was apparently carrying lyssavirus, a virus similar to rabies, according to Agence France-Presse.
Unless treated aggressively after exposure, Australian bat lyssavirus (ABLV) is usually fatal. Since the disease was discovered in 1996, only two other people have died from ABLV, according to Scoop New Zealand.
"ABLV has proved fatal in all cases reported to date. There is a need for increased public awareness of the risk associated with bat contact," Dr. Joshua Francis of Brisbane's Mater Children's Hospital told a conference of the Australasian Society for Infectious Diseases.
"In short, people should stay away from bats," Francis said. He also noted the disease could someday spread from person to person: "Human-to-human transmission of lyssaviruses has not been well documented, but it is theoretically possible."
While many animals harbor zoonotic viruses (those that can jump from animals to humans), bats seem to be in a class of their own. The mammals can carry more than 60 viruses that also infect humans, hosting more viruses per species than even rodents, a recent study revealed. [The 9 Most Bizarre Medical Conditions]
Campbell Newman, the premier of Queensland, is taking the news seriously. "We are prepared to put the health and safety of Queenslanders before bats and we make no apologies for that," Newman told ABC.
But some environmentalists fear Newman may be calling for a culling of bats and flying foxes (an order of large bats) throughout Queensland.
"We always knew that once there was another Australian bat lyssavirus death of a human it would be very serious for flying foxes," Louise Saunders, president of Bat Rescue and Conservation Queensland, told ABC.
"We are just asking people to have a bit of calm and understand that flying foxes are all around us and we need them — they perform an ecological role in our environment," Saunders said.
"They perform a very important role; they are our pollinators and seed dispersers for rain forest and hardwood forest industry," Saunders said.
The best way for people to avoid lyssavirus, according to Queensland Health (the health organization for the state) is to avoid contact with bats and flying foxes.
Lyssavirus isn't the only virus held by bats that can infect humans. Recent research suggested bats are reservoirs for more than 60 viruses that can infect humans, playing host to more viruses per species than even rodents do. For instance, bats carry several harmful infections, including rabies and viruses related to SARS (severe acute respiratory syndrome); studies have even suggested they may be the original hosts of scary viruses like Ebola and Nipah — which causes deadly brain fevers in people.
"There seems to be something different about bats in terms of being able to host zoonotic infections," study researcher David Hayman, a wildlife epidemiologist at Colorado State University (CSU), told LiveScience in February.
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| Posted 12 months ago
Many Human Viruses May Have Jumped from Bats
To better understand the evolution of paramyxoviruses — which also causemeasles, distemper and respiratory infections as well as deadly, newlyemerging Hendra — scientists looked for them in 9,278 individual bats and rodents at sites around the world.
Bats and rodents are known to carry these viruses, and both animals' habit of living in large groups makes them good reservoirs for the viruses that can spread to neighboring humans or livestock.
Their finds included viruses that appear to beclose relatives of those known to infect humans or other animals. [10 Deadly Diseases That Hopped Across Species]
"I can't say we have found measles exactly," said study researcher Dr. Christian Drosten, a professor of virology at the University of Bonn in Germany. "What we have found is surprising genetic diversity around the measles virus."
There was one exception: Mumps. Drosten and colleagues did find the human mumps virus in African fruit bats.It, too, appeared to have relatives in bats.
"Around (the mumps virus)there are so many viruses. We found this virus, the brother, the sister and so on," Drostensaid.Related viruses were typically found within the same social group of animals, but also among animals living far apart or among different species.
The greater degree of genetic diversity of the mumps virus in bats than in humans indicates it started out there before jumping to humans, Drosten said.
Drosten and the international team constructed a phylogenetic, or family, tree for paramyxoviruses using genetic information from those they found as well as those already known. They used the tree to examine which large groups of mammals were infected with different viruses and how these changed over time. The results implicated bats as the ancestral hostsfor two major subfamilies among the paramyxoviruses.
Paramyxoviruses can also infect nonmammals, but little is known about them, according to Drosten.
Vaccination campaigns intended to eradicate diseases, such as smallpox, the livestock-afflicting rinderpest or measles, assume there is no animal reservoir for the virus from which it might return. But these results indicate this assumption should be reconsidered, Drosten said.
"It’s really a wake-up call to incorporate ecological knowledge into the planning of eradication campaigns," he said. "It’s a matter of looking where exactly the viruses are and assessing risk."
The results also indicated the Hendra and Nipah viruses, which cause deadly encephalitis in Asia and Australia, appear to have originated in bats in Africa, where many cases may be going undiagnosed because of a lack of medical infrastructure, he said.
While viral infections were spread out in bats, among all of their major lineages, infections were found only in certain groups of rodents where the viruses were less diverse, they found.
The 86 species of bats sampled represent only 7.5 percent of bat species, so the picture is far from complete.
Drosten cautioned that getting rid of bats is not the answer. He pointed out that the destruction of habitat, such as the rain forest in Africa, is forcing bats, and other wildlife, closer to humans, contributing to a rise in disease epidemics.