Kangaroo Island Cat Control Committee

(Extracts from New Scientist news article, 24 January 2007)

The discovery, announced last week, that the H5N1 bird flu virus is widespread in cats in locations across Indonesia has refocused attention on the danger that the deadly virus could be mutating into a form that can infect humans far more easily.

In the first survey of its kind, an Indonesian scientist has found that in areas where there have been outbreaks of H5N1 in poultry and humans, 1 in 5 cats have been infected with the virus, and survived. This suggests that as outbreaks continue to flare across Asia and Africa, H5N1 will have vastly more opportunities to adapt to mammals than had been supposed. Amin Soebandrio, head of medical sciences at the Indonesian ministry for research and technology, confirmed the report. He says that the infection has also been found in dogs and cats on the Indonesian island of Bali, which has also had outbreaks of H5N1. The new findings follow reports that unusually large numbers of dead cats have been found near many outbreaks of H5N1. Like humans, some cats die, and some recover. But unlike humans, infected cats shed large amounts of the virus and pass it to each other. Infected cats may not directly increase the danger of people catching the virus, as humans seem to catch the current strain only with difficulty even from birds, which they kill, pluck and eat. The main worry, says Albert Osterhaus of Erasmus University in Rotterdam, is that as the virus replicates in cats it will further adapt to mammals and acquire the ability to spread more efficiently to people and from person to person, unleashing a human pandemic.

Osterhaus emphasises that the cat infections still pose a potential threat. "We know the 1918 pandemic was a bird flu virus that adapted to mammals in some intermediate mammalian host, possibly pigs," he says. "Maybe for H5N1 the intermediate host is cats." If similar percentages of cats are infected at every outbreak location, there must have been many thousands of cat infections since the virus emerged, compared to 267 confirmed cases in humans. Every sick cat is a chance for the virus to adapt, and with renewed outbreaks this year in birds, people or both in China, Indonesia, Japan, South Korea, Hong Kong, Vietnam, Thailand, Egypt and Nigeria, it is getting plenty of such chances.

Full New Scientist article here: Bird flu in Cats