Bird flu virus still major concern: WHO

The danger posed by H5N1 avian flu specifically and a flu pandemic in general may no longer dominate news headlines but it has not subsided, experts warned at an international scientific conference on influenza.

"The story has gone away, but the threat hasn't," Dr. Andrew Pavia, head of the Infectious Diseases Society of America pandemic influenza task force, said from Washington, D.C., on Tuesday in a teleconference for journalists. 

The head of the World Health Organization's global influenza program concurred, urging governments and organizations to persevere in efforts to prepare for a future flu pandemic, calling that work "a high public health priority."

"In the assessment of WHO, we believe that the threat of pandemic influenza remains as high as ever," said Dr. Keiji Fukuda, who suggested the recent surge in human H5N1 cases — eight of which have been reported by China — underscores the ongoing problem.

He said the individual Chinese cases have been investigated and WHO believes they represent bird-to-human transmission, not the person-to-person spread that could signal the start of a pandemic.

However, Fukuda said it was "noticeable" that the cases have cropped up in diverse parts of China. "And what that really tells us again is that the virus is really widespread in China," he said.

Vaccine coverage

China is not alone in that reality. Recent human cases have also been reported by Indonesia, Vietnam and Egypt. And the virus is known to be endemic in bird flocks throughout much of Southeast Asia, the Indian subcontinent and parts of Africa as well.

But experts have raised concerns about the fact that cases in China have often occurred in places where there have been no previously reported outbreaks in birds. That suggests surveillance systems are either missing outbreaks or that word of them isn't being pushed all the way up the reporting chain.

Experts are also dismayed by the evidence that the virus is continuing to spread despite massive efforts by Chinese authorities to vaccinate poultry flocks across the country.

Fukuda said, though, that it is not unexpected to see occasional cases, particularly at a time of year when an upswing in infections has historically been noted.

"The vaccine coverage is not perfect. It's clear that not every bird in every country gets vaccinated. And it's also clear that there are certain kinds of birds like ducks and geese which don't respond to vaccine but which easily get infected by these H5 viruses," he said.

"So when you put that all in the mix, I think that it's not surprising that we will see individual cases occurring in countries even with high vaccination coverage rates."

Public reporting of cases

Fukuda praised China's efforts, noting the country has reported its recent human cases promptly — a welcome trend.

"Hopefully we will see this become just a standard of behaviour for all countries," he said. "Anyway, it's very nice."

Fukuda did not name countries which aren't reporting as quickly as China.

But Indonesia, which has had more cases of H5N1 than any other country, is currently following a policy of only publicly reporting human infections from time to time rather than as they occur.

The country has been locked in a dispute with the WHO and other countries over the sharing of virus samples for the past two years. Health Minister Siti Fadilah Supari has insisted Indonesia will not share virus samples unless it receives assurances it will receive a supply of any vaccine made from the viruses.

China, which was pilloried internationally for trying to cover up the emergence of Severe Acute Respiratory Syndrome or SARS in 2003, did not always report its H5N1 cases rapidly, either. But of late authorities have been alerting the international community within days of confirming new cases.

"I think China has had its fair share of experience with these emerging infectious diseases and I think in general they have made huge strides," Fukuda said.

But he suggested surveillance for H5N1 outbreaks still needs to improve.

"We need to be able to have more information on cases, both human cases and animal cases. And so I think it just points out that there's more work to be done in this area."