So far, this has not happened. Bird flu has only infected some 200 people worldwide and in practically every case, the victims were farmers or livestock traders who caught the disease directly from their animals.
However, attention has been focused on a remote Indonesian village where seven members of the same family have died of bird flu. Experts say this is the largest family cluster of bird-flu victims to date. It appears likely that human-to-human transmission was responsible.
The Indonesia Cluster
In the village of Kubu Sembelang, in northern Sumatra, eight members of the same family have been struck down by the disease.
Joned Ginting watched helplessly as his son, sister, and other close relatives died from bird flu this month. He himself is now fighting for his life.
The Gintings were not poultry farmers. No infected animals have been found in the village. Scientists do not know how they got infected.
But they believe that whoever in the Ginting family caught the virus first probably passed it on to other family members. That means likely human-to-human transmission, a worrying development.
"We have a team down there [in Indonesia] looking around, and we can't find any obvious source of infection -- no infected poultry, no infected pigs -- so, we're puzzled," said Peter Cordingley, WHO spokesman for the West Pacific region, at a news conference in Manila on May 24. "I mean, first of all, we're puzzled -- how did they get sick? And, secondly, how did this virus affect so many people?"
Cordingley said the outbreak has alarmed scientists. There have been previous, isolated reports of possible human-to-human transmission in Asia, but nothing on this scale.
"This case in Indonesia is probably the most worrying incidents, so far, since bird flu started nearly three years ago," Cordingley said. "We have a very large cluster of seven [infected] people, probably eight. We've not seen a cluster that size."
No Cause For Panic
Despite this development and the WHO's concern, leading experts on bird flu contacted by RFE/RL say it is no cause for panic.
It appears from tests conducted on the Indonesian victims that the bird-flu virus did not mutate. If that is confirmed, then we need not fear a pandemic -- for now -- according to Albert Osterhaus, a senior virologist at the Erasmus Medical Center in the Netherlands. All that this case would prove is that bird flu can be passed between humans who share very close, extended contact. But bird flu probably remains impossible to catch from casual contact.
"That's the key question, of course," Osterhaus said. "If indeed it can be proven that no mutation has been found or is present yet, then of course the virus has not changed. And we have seen in the past indications of very limited human-to-human transmission. So then the situation would not have changed dramatically, because we then we would just learn that the virus, under certain conditions, can indeed be transmitted from human to human. But it is not able yet of being transmitted efficiently in the population, from human to human."
John Oxford, professor of virology at Queen Mary College in London, also cautioned against jumping to conclusions.
"I'm not over-concerned at this precise moment, because there's been some evidence of a similar sort of thing, obviously not so dramatic -- and it's really unfortunate for this poor family in Indonesia -- but there have been other incidents in Southeast Asia, in Thailand and in Vietnam, where we thought there was some indication of human-to-human transmission," Oxford said. "So, to my mind, this is a little bit more dramatic but more of the same sort of thing. And on top of that, this is still a virus spreading within a family group. And we all know that families are very close communities. And that does mean, at this precise moment, that this virus is necessarily is going to break out."
Virus Remains A Mystery
Still, scientists admit that they still know far too little about the virus and how it spreads.
"We [know] that our knowledge is very limited so far," Osterhaus said. "The only thing we have learned in the last year or two is that this virus can probably spill back from the poultry population, which is suffering from highly pathogenic avian influenza, into wild birds. And then it can become endemic in wild birds. That's what we have learned. We do not know too much about what the virus does in the wild-bird population. And I think we need much more data on that to be able to more accurately predict what's going to happen in the future."
An expert at the National Virology Laboratory of the Kyrgyz Health Ministry (courtesy photo)
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