Health officials in Indonesia monitoring suspected bird flu cases, say as many as 48 people may be infected with the virus. But, the World Health Organization says the number of actual avian flu cases in the country may not be as high as initial reports suggest.

A man prepares to release race pigeons in Jakarta

At least four people have died from the H5N1 avian influenza virus in the Indonesian capital of Jakarta since July and dozens more have been admitted to local hospitals with symptoms of the disease, which include high fever and difficulty breathing.

But the World Health Organization's spokesman for the Western Pacific, Peter Cordingley, says many of those now in hospital may not be infected with the bird flu virus at all.

Mr. Cordingley says Indonesia sends blood from all suspected bird flu cases to Hong Kong for a Polymerase Chain Reaction, known as a PCR, test, and only four people - all now dead - have tested positive.

"WHO figures are that there are four confirmed cases, only four confirmed cases in Indonesia," he said. "The reason for the discrepancy, apart from the fact that the media seem to be jumping on all kinds of incidences that might be just old-fashioned flu ... is that we have standards and the standards are that confirmation of a positive case has to be through a PCR test." 

But Mr. Cordingley admits Indonesia does have a bird flu problem, with the H5N1 virus endemic in poultry across the archipelago.

"... yes, quite clearly there is a problem in Indonesia and four cases will not be the final number - we are absolutely sure of that. But we do not think the problem is anything as large as the numbers suggest," he said.

The bird flu has killed more than 60 people in Asia since it swept across the region in late 2003 and millions of birds have been culled to try to stop the spread of the disease.

Most of the people who have died from H5N1 have caught it from close contact with infected birds.

But the WHO has warned that if the virus changes to one easily passed between humans, the resulting pandemic could kill millions of people.

Health experts from the United States, Canada, and Australia are now in Indonesia to help the country tackle its bird flu problem.