ROME, Italy, July 12, 2004 (ENS):
New outbreaks of the avian influenza virus H5N1 in China,
Thailand and Vietnam confirm that the virus is still
spreading in the region, the United Nations agency responsible
for food and agriculture said Friday. This viral strain
caused the deaths of more than 100 million chickens
and ducks in Asian countries earlier this year. Some
birds died from the flu, but the vast majority were
culled in an attempt to control the virus.
"The new cases do not come as a surprise,"
said Joseph Domenech, chief of the UN Food and Agriculture
Organization's Animal Health Service.
China reported a new outbreak of bird flu last Tuesday.
It was China's first report of the H5N1 virus since
the government declared it had stamped out the disease
nearly four months ago. Tests at a farm in the southeastern
province of Anhui have confirmed that chickens died
of bird flu, the government said on state-run television.
In Thailand, authorities said they suspect a new outbreak
of bird flu at a farm in the central province of Ayutthaya.
Thousands of chickens at the farm have died.
Bird flu has also been confirmed on farms in Vietnam
in recent days, and about 4,700 chickens have died.
"After the major outbreaks of a few months ago,
affected countries succeeded in bringing the disease
under control. But the new outbreaks clearly demonstrate
that the virus continues to circulate in parts of the
region and new cases might flare up in future, posing
a continuing threat to human health," Domenech
"In designing their control strategies governments
need to acknowledge that the virus will continue to
circulate and that different flu viruses could also
be introduced. Eradication of the avian flu virus should
be considered, at best, as a long-term task," he
The World Health Organization (WHO) said Thursday that
these outbreaks could either be new outbreaks of the
highly pathogenic avian influenza A H5N1 virus, or,
a continuation of the outbreaks first reported earlier
"These events, in addition to two new research
reports about the virus becoming increasingly pathogenic
and becoming more widespread in birds in the region,
fuel the World Health Organization's concern about the
threat the virus poses to human health," the agency
Several countries in Asia have documented this virus
crossing the species barrier - moving from infected
chickens or ducks directly into humans - three times
since 1997 with severe, and sometimes fatal, outcomes.
"The virus has the potential to acquire the ability
to spread easily from human to human, and, thus, trigger
a global influenza pandemic," WHO said.
The two research resports that worry WHO officials
were both published this month. First, members of China's
Ministry of Agriculture, and colleagues, reported, in
a paper published in the "Proceedings of the National
Academy of Sciences," that the virus appears to
be widespread in domestic ducks in southern China. The
scientists found that the virus is causing increasingly
severe disease, but these tests were done in mice and
"may not have a direct implication for humans,"
Last week, the journal "Nature" published
a report which indicates domestic and wild birds in
the region may have contributed to the increasing spread
of the virus, and, suggests that the virus is gaining
a stronger foothold in the region. These observations
suggest that control of the virus may be even more difficult
than thought in the spring.
K.S. Li and 21 others from universities in China, Indonesia,
Thailand, Vietnam and the United States are coauthors
of the "Nature" article. "Our results
suggest that H5N1 viruses with pandemic potential have
become endemic in the region and are not easily eradicable,"
they write. "These developments pose a threat to
public and veterinary health in the region, and, potentially,
the world, and suggest that long-term control measures
It is probably unreasonable to expect that the disease
can be totally excluded from the region in the near
future, Domenech said. In his view, managing the risk
that the viruses pose to human health and animal productivity
is the challenge. "The presence of highly pathogenic
strains of the virus in wild birds makes control of
the disease particularly complex and difficult,"
It is very encouraging that governments have reacted
immediately on recent outbreaks and have officially
informed international organizations, the FAO said.
This demonstrates that country surveillance systems
are becoming operative.
But the UN agency warned that surveillance and immediate
reaction to outbreaks need to be strengthened and applied
in all countries of the region. "In some countries
the extent of infection is still not precisely known
and further investigation is urgently needed,"
"Countries should apply surveillance and control
measures nationwide and should consider the fight against
bird flu as a long-term commitment. There is no easy
solution to the problem," he said.
Currently, there are indications that the virus is
still present at least in Cambodia, China, Indonesia,
Thailand and Vietnam providing the potential for renewed
epidemics as poultry production systems are re-stocked
with vulnerable birds.
Pandemic preparedness activities started by WHO in
the wake of the outbreaks reported earlier this year
At the end of June, WHO hosted a meeting in Kuala Lumpur,
Malaysia with experts from 13 countries and areas of
the Asia-Pacific region. Participants were provided
with a WHO preparedness self-assessment tool.
WHO is collaborating with scientists, and the pharmaceutical
community, on a global surveillance system to monitor
changes in the virus's susceptibility to known antivirals.
And vaccine development continues. Two vaccine manufacturers,
both based in the United States, have produced a supply
of trial vaccine which will be tested for safety and
efficacy in humans.
Key elements of a successful control strategy are surveillance
operative in all production systems, strengthened biosecurity
of commercial enterprises and an immediate response
to outbreaks including stamping-out in affected areas,
plus disinfection, restriction of movements of animals
and goods, and public awareness campaigns.
Copyright Environment News Service (ENS) 2004. All