Health authorities in China are refusing to disclose the origins of an avian influenza (bird flu) virus that can be lethal when transmitted to humans, a senior South African medical official said on Tuesday.
Stephen Toovey, medical director of SAA Netcare Travel Clinics, said in a statement that this is raising fears among scientists and the World Health Organisation (WHO) that a virulent flu epidemic could sweep across the globe.
He said the virus could be the source of the flu that has affected 18 people and is suspected of having caused a total of 13 deaths in Vietnam since the beginning of the year. The cause of death in four of these cases has been confirmed as bird flu virus.
”These fears are fuelled, in part, by the parallels between the current bird flu epidemic in Asia and the 2003 outbreak of severe acute respiratory syndrome [Sars], which killed around 800 people and infected about 8 000,” said Toovey.
”For starters, China refused to acknowledge the existence of the Sars outbreak initially, thereby allowing it to spread unchecked for several months.”
He said the bird flu virus (influenza A/H5N1) identified in Taiwan, Vietnam, South Korea and Japan, appears to have its origins in China’s southern Guangdong province — as did the Sars virus.
He said although A/H5N1 previously killed only chickens, it is currently also afflicting wild birds, ducks, geese and even pigs — a development that points towards the greater probability of the virus ”jumping” to humans through close contact with infected livestock.
”Although there is no evidence of person-to-person transmission to date, the possibility that the virus could acquire this capability increases as more and more people become infected.
”Should the virus hybridise by capturing human genes, the disease would spread more readily among humans and could spark an epidemic far deadlier and more widespread than Sars and possibly as destructive as the Spanish flu pandemic, which killed at least 20-million people worldwide in 1918.
”Interestingly, microbiologists believe that the Spanish flu virus also originated in Guangdong province where the practice of raising ducks, geese, chickens and pigs alongside each other in high-density farms has produced a reservoir of mutating viruses.”
Toovey said in an effort to contain an outbreak, the WHO has begun assembling a team of international experts that will be tasked with discovering how to minimise the risk of person-to-person transmission. Its task is particularly challenging given that stocks of vaccine against influenza A/H5N1 are inadequate to stave off a pandemic.
”Moreover, the production of additional vaccine would require vast quantities of chicken eggs — a commodity that could well be in short supply should the bird flu epidemic spread elsewhere in the world. More than two million chickens in Vietnam alone have already died as a result of the disease or been slaughtered to stop its spread,” concluded Toovey. — Sapa