TORONTO -- 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 warn.
"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, says.
The head of the World Health Organization's global influenza program concurs and urges 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," says Dr. Keiji Fukuda, who suggests the recent surge in human H5N1 cases -- eight of which have been reported by China -- underscores the ongoing problem.
He says the individual Chinese cases have been investigated and WHO thinks they represent bird-to-human transmission, not the person-to-person spread that could signal the start of a pandemic.
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However, Fukuda says it is "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 says.
Recent cases
China is not alone in that reality. Recent human cases also have 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 often have 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 also are 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 says, though, 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 says.
"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," he says.
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Reporting errors
Fukuda is praising 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 behavior for all countries," he says. "Anyway, it's very nice."
Not all countries are reporting outbreaks in a timely manner, Fukuda says.
But Indonesia, which has had more cases of H5N1 than any other country, currently is 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 says.
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But he suggests 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."
