To date, it hasn't been proved that cats can transmit the virus to humans, but researchers at the Erasmus University of Rotterdam, the Netherlands, discovered that the felines can infect each other and become infected by ingesting the meat from sick birds, according to a report published in late March in the science magazine Nature.
Cats could have "a more important role than we thought" in spreading avian flu, according to the Dutch research team, headed by virologist Albert Osterhaus. The scientists also warn that it cannot be ruled out that cats might contribute to a mutation of H5N1 to a strain that is more easily transmitted amongst humans, which could indeed trigger a pandemic with the potential to kill millions of people around the world.
Since 2003, 191 people have been infected with avian flu in Asia, but only through direct contact with sick birds.
In the northeastern Austrian city of Nickelsdorf, the Health Ministry ordered euthanized two cats that were found to have H5N1 antibodies in their blood. In a press communique, following an outcry from animal protection groups, the ministry defended the measure with the argument that "it would have been impossible to provide adequate protection."
Animal shelters in Germany complain that cat and dog owners are getting rid of their pets en masse. "The problem isn't that they fear an infection, but rather that by following the instructions of the health authorities they had to restrict the living space" of their pets, said Nicole Mindrup, director of the animal protection committee in the southern German city of Wiesbaden.
In eastern Germany the feeling of panic intensified in early April after some 700 turkeys died of the disease on a local farm.
The influenza was probably transmitted to the turkeys from infected wild birds that entered the farm undetected, according to local officials.
In France, the government is asking owners of cats and dogs to avoid taking their pets outside of the home, and if it is necessary, to transport them in cages or enclosed vehicles.
These recommendations were made despite the fact that AFSSA, the French food health safety agency, concluded in a March report that "the probability of humans being infected with the H5N1 virus by cats is nil."
The first cases of the H5N1 virus in felines were reported in 2004 in Thailand, where 14 cats died after eating the remains of infected birds. Tigers and leopards at a Thai zoo were also infected through similar means.
In the laboratory tests conducted by Osterhaus' team, cats fed infected meat contracted the disease and transmitted it to other cats in the same cage through their breath.
But not everyone believes that Osterhaus' findings merit a serious warning. For Jean-Luc Guerin, professor at the veterinary school in Toulouse, France, the spread of the disease reported by the Dutch virologist occurred under exceptional conditions.
"In the laboratory case (of Osterhaus), the infected cats were subjected to great promiscuity, forcing extreme contact with the virus," Guerin said in a Tierramerica interview.
The expert stressed that the quantities of virus found in the infected cats' feces was considerably less than that found in the droppings of birds with the disease.
"Given that in Asia -- where there has been massive exposure of domestic animals to the virus for the past two years -- only a couple of cases of spontaneous infection were reported, there is no reason to talk about a risk of bird flu epidemic among cats," said Guerin.
In Germany, the Friedrich-Loeffler Institute for virus and veterinary research suggests that cat owners wash their hands each time after handling the animals, their litter boxes or bedding.
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April 20, 2006 (http://www.albionmonitor.com)
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