The Department of Environmental Conservation of Alaska (United States) has confirmed the first known case of the death of a polar bear infected by the H5N1 bird flu virus worldwide. The animal’s corpse was found in October near the town of Utqiagvik, in the North Slope region, in Alaska (United States).
The information has not been released until now because “the discovery of the virus in the animal’s body tissue has been a process that has required sampling and study by the North Slope County Department of Wildlife Management and other agencies ”, said veterinary doctor Bob Gerlach, of the Global Center for Health Security, at the University of Nebraska School of Medicine.
“It’s the first reported case of a polar bear anywhere,” said Gerlach. As such, the World Organization for Animal Health was informed and has drawn attention to other Arctic nations that have polar bears, he said.
Wildlife and animal health experts are studying the possible origin of the infection in the dead polar bear. They point out that it is also the first animal included in the Endangered Species Act in Alaska that has fallen victim to bird flu. The extent of this epizootic may affect polar bears, which depend on sea ice that is shrinking due to climate change, and which were listed as a threatened species in the United States in 2008.
While polar bears typically eat seals that hunt on sea ice, it seems likely that this bear was scavenging on dead birds and ingested the flu virus that way, Gerlach said. According to the Department of Environmental Conservation, many birds of various species on the North Slope have died due to this bird flu. From what is known so far, it would be necessary for the bear to directly eat an infected bird to contract the disease, as explained by Professor Gerlach in statements published by the Juneau Empire.
“If a bird dies from H5N1, especially if the body is kept in a cold environment, the virus can stay alive for a while,” said this expert. The death of the polar bear would in this case be a worrying sign of the persistence and extension of this strain of highly pathogenic avian influenza, identified for the first time in North America two years ago, animal health authorities have indicated in Alaska.
“What we are observing now is a scenario that we had not known until now, so there is no manual of action and the maximum possible precautions must be taken”, said Andy Ramey, wildlife geneticist of the Geological Survey of the United States and an expert on bird flu.
The H5N1 subtype of the bird flu virus has caused millions of bird deaths (domestic and wild) in various places around the world since its original detection in China in 1996. This version of what is also known as bird flu or avian influenza, moreover, has been detected in the last two years in 42 species of mammals in ten countries, including Spain, where cases were detected in mink farms in Galicia.
In September, a health emergency was activated in the Galapagos Islands due to the death of birds infected by this virus and in October the first cases of birds infected with this flu were confirmed in the Antarctic area, and several experts warn of the danger to penguin populations.
Avian influenza A viruses generally do not cause infection in humans, although sporadic cases of this type of illness in humans have been reported in recent years, including the H5N1 subtype.
