'Worrisome' flu cluster: International Herald Tribune

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'Worrisome' flu cluster draws experts' attention

By beth Rosenthal International Herald Tribune

THURSDAY, MAY 25, 2006

A team of World Health Organization experts has been deployed to help

investigate what is being termed " a worrisome " family cluster of

human cases of avian influenza in northern Indonesia, organization

officials said Wednesday.

But they emphasized that lab tests from the family did not suggest

that the H5N1 bird flu virus had mutated in any way that would allow

it to spread readily among humans, a change that scientists have said

could set off a devastating pandemic.

While the H5N1 avian virus has killed hundreds of millions of birds

in the past several years, it is poorly adapted to humans and has

infected only 214 people, almost all of whom have had close contact

with sick birds.

The six stricken family members from northern Indonesia did not keep

birds, and were not from a village with a known avian influenza

outbreak. But there are numerous potential routes of exposure in

rural areas of Southeast Asia, particularly in Indonesia, which has

been struggling to contain the disease. At least some members of the

stricken family sold fruit or vegetables at a market where birds are

sold and slaughtered, a health official said, and could have

contracted it there.

Dick , a World Health Organization spokesman who just arrived

to join the seven-member team, said: " Certainly this is the largest

cluster we have in humans, and that by itself is worrying. There's a

suggestion of human-to-human transmission, and that is worrying. So

we are certainly concerned about this. "

In the past, there have been a very few cases of bird flu in humans

in which health officials suspected that people extremely ill with

the disease had passed it to family members. An example would be

possible transmission between a mother and a child who shared the

same bed.

The Indonesian cluster involves a larger number of potentially linked

cases. The six people who have the disease are part of an extended

family of eight from Kubu Sembelang village in North Sumatra. A

seventh family member died but was not tested before burial.

On April 29, three people who later fell ill shared a small room with

the mother of the family, who was gravely ill and coughing, and has

since died. Others who have been stricken cared for family members

who were dying. There are no cases reported in the village outside of

the family.

" We do not have any indication at all that animals are involved in

the transmission, " said Lubroth, a senior veterinarian at the

United Nations Food and Agriculture Organization in Rome. But he

cautioned that poorly regulated bird markets were still functioning

in Indonesia.

Many human victims of bird flu have been involved in caring for or

slaughtering sick poultry. The risk has proved particularly high when

the slaughter takes place in the unsanitary conditions of makeshift

street markets or in the home.

Indonesia is in the midst of a prolonged and only partly successful

campaign to control the wildfire spread of avian influenza in its

poultry, international officials said. Six veterinarians from the UN

Food and Agriculture Organization have been stationed there since the

beginning of the year.

" It has been a difficult situation because of Indonesia's

decentralized government system, " Lubroth said. " There is a national

strategy, but it's too early to say how it's panning out. "

Vietnam has had success in controlling avian influenza in its poultry

using vaccinations against H5N1, but it is a much smaller country

with much tighter control on commerce.

Recent scientific research has demonstrated that one of the reasons

avian influenza does not spread easily among humans is that it

infects cells deep within the human lungs.

As a result, for transmission to occur, exposure must be intense and

prolonged to someone with a deep cough, doctors suggest. Normal human

influenza virus lives in the throat and nose, and so spreads readily

through sneezes.

There is no evidence suggesting that the H5N1 avian influenza virus

is poised to acquire that ability. A WHO reference lab has already

looked at the genetic sequence of the virus that infected the Sumatra

family and found that it is similar to the one that has been

infecting birds in Indonesia. " It's still a purely avian virus

without significant mutations that would make it better adapted to

humans, " said.

http://www.iht.com/articles/2006/05/24/news/flu.php