Keep cats indoors if avian flu nearby, researchers warn

People living in areas where avian flu has been found in birds should keep their cats inside, European scientists say.

Cats have been known to become infected with the deadly H5N1 strain of bird flu and lab experiments show they can spread it to other cats, the researchers wrote in Thursday's issue of the journal Nature.

Nobody knows whether cats can transmit the virus to birds or people, the scientists said. It is difficult to know what risk cats pose because so little is known about the virus, they added.

"We believe that the potential role of cats should be considered in official guidelines for controlling the spread of H5N1 virus infection," wrote virologist Albert Osterhaus and colleagues at the Erasmus Medical Centre in Rotterdam, the Netherlands.

Peter Roeder of the Food and Agriculture Organization of the United Nations also contributed to the study.

The scientists recommended cats be kept away from H5N1-infected birds or their droppings. Cats suspected of contacting either or showing symptoms of viral infection should be quarantined and tested, they said.

In areas where H5N1 has been found, cats should be kept indoors, they said.

The warning echoes a recommendation by the European Centre for Disease Prevention and Control, which suggested keeping cats indoors if they lived within 10 kilometres of a verified H5N1 infection in birds.

The H5N1 strain of bird flu has infected 191 people in eight countries, mostly in Asia, and killed 108, according to the World Health Organization. The disease is difficult to catch and doesn't pass from person to person.

Some scientists fear the virus could mutate into a form that can spread more easily, leading to a pandemic.