Six people in Hong Kong who caught influenza from chickens may turn out to be the first patients in a worldwide epidemic caused by a new flu strain, says an expert who predicts that “it’s only a matter of time” until the virus starts spreading from human to human.
Robert G. Webster, a member of the World Health Organization influenza team and virus expert at the St. Jude Children’s Research Hospital in Memphis, Tenn., said Monday that a unique strain of flu never before seen in humans could rage around the globe if the virus mutates so that it can be transmitted between people. Flu shots now in use offer no protection, he said.
“There is no evidence yet of human-to-human transmission, but the very nature of this virus (means)… it will acquire that property,” said Webster. “It is only a matter of time.”
When that might happen, he said, is unpredictable.
Webster, just returned from Hong Kong, said six cases of a flu called H5N1 have been confirmed, all in patients thought to have contracted the virus from live chickens. Two patients have died. One of the deaths is linked to a complication of treatment and not directly to the flu. A 2-year-old boy recovered after being hospitalized in November, and three more people remained hospitalized.
A large wholesale poultry market in Hong Kong was shut down Monday and will not reopen until Thursday, the government said. Vendors at the Cheung Sha Wan Poultry, which sells more than one-third of the 80,000 chickens imported into Hong Kong daily from China, asked for a cleanup to restore public confidence in poultry - even though no infected chickens have been found there.
At least 10 WHO laboratories around the world are making preliminary preparations to combat a possible pandemic, or international epidemic, from this new strain of flu.
“We are gearing up as if this is the real event,” said Webster. “The scientists of the world at this time are doing their very best to come up with a suitable vaccine.”
H5N1 is the first flu virus known to spread from birds to humans. Most new strains of flu develop in swine and are then passed to humans. Because H5N1 is a new strain, the human immune system is virtually defenseless against it.
Webster said the virus kills chickens and chicken eggs. Since chicken eggs are used routinely to make flu vaccine, scientists are searching for other ways of making vaccine against H5N1. He said it may be possible to use a closely related virus that does not kill chicken eggs to make a vaccine against the new flu, but that has yet to be proven.