Travel Forum / Destinations / Asia / May 2005

Bird flu capable of human-to-human infection
(Agencies)
Updated: 2005-05-19 15:46

GENEVA - A World Health Organisation study in Vietnam has raised the
possibility that bird flu is becoming more capable of human-to-human
transmission, the WHO said.

The study of bird flu outbreaks in Vietnam until April 2005, presented
to a meeting with Asian countries in Manila on May 6, suggested an
evolution of infections by the H5N1 virus in Vietnam, according to a
report on the meeting.

A bird flu patient lies under a respirator at Hanoi's Institute for
Tropical Diseases. A World Health Organisation study in Vietnam has
raised the possibility that bird flu is becoming more capable of
human-to-human transmission, the WHO said.(AFP/
A bird flu patient lies under a respirator at Hanoi's Institute for
Tropical Diseases. A World Health Organisation study in Vietnam has
raised the possibility that bird flu is becoming more capable of
human-to-human transmission, the WHO said. [AFP]
"The changes in the epidemiological patterns are consistent with the
possibility that recently emerging H5N1 viruses may be more infectious
for humans," it said.

While that meant a greater number of people might be infected by
poultry, there was also evidence that human to human transmission,
which has already been found several times since the strain was first
detected in Hong Kong in 1997, was strengthening, the UN health agency
said.

"It is possible that avian flu viruses are becoming more capable of
human-to-human transmission," the report said.

"While the implications of these epidemiological and virological
findings are not fully clear, they demonstrate that the viruses are
continuing to evolve and pose a continuing and potentially growing
pandemic threat," the report said.

Fears of that a new deadlier strain of flu might spread rapidly around
the world on a similar scale to pandemics in the last century have been
revived with the emergence of the H5N1 bird flu virus among humans in
Asia.

Fifty-two people have died in Vietnam, Thailand and Cambodia since late
2003, mainly through infection from poultry.

Concern is now heightened because a pandemic strain may develop through
a series of small steps that taken individually might not be enough to
signal clearly that an epidemic was about to start, according to the UN
health agency.

"It is not sudden event but a complex sequence of events that lead to a
pandemic," said WHO official Richard Nesbit.

The pattern of changes observed in north Vietnam included more and
larger human clusters of the disease, the increasing mean age of the
victims and the lower fatality rate.

Analysis of genes from both avian and human forms of H5N1 from several
countries also suggested changes in the virus, the report said.

The report reiterated the health agency's call for "immediate steps" to
boost monitoring for possible pandemic influenza in all countries
affected by H5N1 in birds.

It also recommended that all countries, including those which were
unaffected by the strain, should move ahead with operational plans to
tackle a possible global spread of deadlier form of flu.

Other interpretations for the trends observed in Vietnam were raised,
including transmission through contaminated water or food or infection
from poultry that carried the virus but did not show symptoms, or
greater persistence of the virus in the environment.

The experts meting in Manila also considered that the changes seen in
north Vietnam could be "inconsequential" but dismissed that assessment
as unlikely.

A second human case of bird flu was identified in under a week in
Vietnam on Tuesday.

Thirty-six people have died from the disease in Vietnam since late
2003.