Asia wings it when it comes to bird
flu By Bruce Klingner
The
resurgence of the deadly H5N1 strain of avian influenza
("bird flu") in Asia after months of apparent
quiescence, combined with the first reported case of
human-to-human transmission in Thailand, has resurrected
fears of a potential global pandemic. Recent outbreaks
have been identified in Cambodia, China, Indonesia,
Malaysia, Thailand and Vietnam, despite massive
government culling programs of tens of millions of
poultry earlier this year.
The World Health
Organization (WHO) characterized the simultaneous
outbreaks of the H5N1 influenza in 2003-04 as
"historically unprecedented". The United Nations Food
and Agriculture Organization (FAO) and the World
Organization for Animal Health (OIE, or Office
International des Epizooties) jointly concluded earlier
this month that the epidemic is a "crisis of global
importance" and that the "virus will not be eradicated
in the near future". Although only 43 people have been
infected by avian flu to date, 72% of those have died, a
fatality rate similar to that of the Ebola virus.
Health authorities warn that if a hybrid strain
of bird flu were to combine with human influenza, it
could have a potentially devastating impact similar to
the "Spanish Flu" epidemic of 1918-19 that resulted in
more than 20 million human deaths.
Requirements for a pandemic Health
experts explain a pandemic requires the development of a
new strain of influenza that has the ability to spread
not only from animals to humans, but also from human to
human. Such a virus would be spread rapidly since no one
would have innate immunity and existing vaccines would
not provide protection. An animal influenza virus can
acquire the ability to spread among humans either
through chance mutation or if a person already sick with
a human influenza virus also became infected with H5N1,
allowing the viruses to mingle and form a new, deadlier
strain.
The WHO assessed earlier this year that
the H5N1 virus has a high propensity for mutating
rapidly and acquiring genes from viruses infecting other
animals, providing it the ability to jump to other
species. US and Chinese researchers studying H5N1
strains taken from ducks in China between 1999 and 2002
determined that the virus has become more virulent and
deadly during the past several years, according to a
study published in the Proceedings of the National
Academy of Sciences.
Domestic poultry are
particularly susceptible to epidemics of rapidly fatal
influenza, and migratory waterfowl have been identified
as "reservoirs" for H5N1. The virus can also mutate
within pigs, which are susceptible to infection from
both bird and human viruses.
On the watch in
Asia To prevent further outbreaks, as well reduce
the opportunity for the virus to mutate, the WHO has
urged governments to make "rapid elimination of the H5N1
virus in bird populations [a] high priority as a matter
of international public health importance". Although
culling operations reduce human exposure, the large
number of humans living in close proximity to poultry
throughout Asia, and the ability of the virus to survive
for lengthy periods in cold weather, require long-term
measures to be implemented. Previous epidemics involving
the less dangerous strains lasted for several years.
Denying the problem The tendency of
some governments to cover-up outbreaks of avian flu is
worrisome. At the initial stages of last year's
outbreak, Bangkok vehemently denied for weeks the
possibility that bird flu existed in Thailand, only
admitting the truth after three people had been
diagnosed with the disease. Thailand's Deputy
Agriculture Minister Newin Chidchob commented at the
time, "If we find this disease in Thailand, the chicken
industry will collapse immediately. We would lose more
than 100 billion baht [US$2.56 billion]." The Thai
government's chief spokesman said the outbreak had been
concealed for "a few weeks" in order to avoid panic.
Thailand is one of the world's top five poultry
exporters. After Bangkok announced the existence of
avian flu, the European Union, Japan, and several other
Asian countries banned imports of Thai chickens and
stock prices of chicken producers plunged on the Bangkok
share market.
Prime Minister Thaksin Shinawatra
dismissed on October 12 the recommendation of the
Livestock Development Department to produce an avian flu
vaccine and strongly criticized the department for
"confusing the public over the issue". He also directed
all government agencies to refrain from giving press
interviews without first clearing the information with
Deputy Prime Minister Chaturon Chaisang. The director
general of Thailand's Department of Disease Control, D
Thawat Suntrajarn, asserted that avian flu did not
represent a global threat and that the virus was not
easily transmittable between humans.
Vietnam
announced that it had contained the latest avian flu
outbreak, and Bui Quang Anh, a spokesman for the
Ministry of Agriculture and Rural Development, denied
that Hanoi was covering up additional cases of the
disease, despite its refusal to release test results of
a boy who died in September from suspected bird
flu.
The WHO refuted statements made by
Indonesian officials earlier this month that the H5N1
strain of bird flu circulating in the country was
different from the virus found in Vietnam and Thailand,
and said that "Indonesia has an H5N1 virus with
genotype-z that cannot be transmitted from poultry to
humans." WHO expert Steven Bjorge said that all of the
H5N1 bird flu outbreaks in Asia were variants of the
same genotype, which is highly pathogenic to birds and
could also be transmitted to humans. Tri Stay Putri
Naipospos, the director for animal control of
Indonesia's Agriculture Ministry, claimed the disease
"is now under control".
China - the biggest
worry? China, again, casts a long shadow over the
rest of Asia. Health experts fear a looming crisis in
China, the source of the deadly severe acute respiratory
syndrome (SARS) virus, which some assess had likely
mutated from an animal disease. During the 2003-04 avian
flu outbreak, Beijing established "guidance" for
domestic media to follow in reporting on SARS and avian
flu, and officials intimidated members of the media that
did not comply.
China initially denied that the
avian flue virus existed in country, despite it having
been identified in poultry meat exported to its
neighbors, or that the source of the disease was
Guangdong province, where the SARS virus had begun. A
WHO official commented in January that, despite repeated
requests, China had failed to be forthcoming with
information. "We are very afraid that their attitude to
avian flu is the same as it was to SARS last winter -
and that we are heading for a repetition of that
fiasco," the official said.
Chen Hualan,
director of China's National Avian Influenza Reference
Laboratory in Harbin, revealed in August that Chinese
government scientists had confirmed the presence of H5N1
avian influenza in pigs during 2003-04, but Beijing
never informed international health authorities.
Concerns remain that Beijing might suppress information
about future outbreaks.
Near-term
outlook The disease is now permanently
established in poultry throughout most of Southeast
Asia. Outbreaks among fowl and humans will continue to
occur and will probably increase over the next 30-90
days since the disease has historically been more
prevalent during the winter months. The level of poultry
and human outbreaks will be highly dependent on imposed
health and travel restrictions. Government denials of
outbreaks, which delay remedial quarantine and culling
efforts, would only raise the risks for additional
infections.
Implications for the
future Health officials fear that an influenza
virus that led to widespread sickness would cause
massive disruption to a nation's health-care system and
inhibit the government's ability to maintain essential
services. A large portion of the population would be
sick, virtually all at once, overwhelming doctors and
hospitals. Beyond the direct cost of care and medicines,
the overall economic implications would be staggering,
not only for the poultry industry - a key component of
several Southeast Asian economies - but also other meat
industries impacted by loss of consumer confidence and
reductions in the tourist and transportation sectors,
resulting from international quarantines.
What would cause a panic? Reports of
additional outbreaks of avian flu in other Asian nations
would cause immediate imposition of government culling
programs and quarantines in an attempt to limit the
economic impact. Confirmation of human-to-human
transmission would cause an increased level of concern,
especially if it were to occur simultaneously in several
countries. Confirmation of widespread outbreaks in
China, or indications of government suppression of
information, would significantly raise international
anxiety.
Occurrences of the H5N1 avian flu in
humans outside of Asia, perhaps caused by travelers
returning with the virus, could cause widespread panic
and draconian government restrictions on travel and
international economic activity. Taiwanese Health
Minister Chen Chien-Jen warned on October 8 that a
deadlier variant of avian flu "could spread rapidly, and
an infected person could transmit it to several people
at once. The virus could spread throughout the world,
leaving from Asia and reaching the United States and
Europe." He warned that European imports of live poultry
from Asian countries are potential risk factors that
could result in the spreading of the virus.
Governments would respond by seeking to
stockpile a vaccine. The Etopia Media Medical News
Network reported that the US National Institutes of
Health in late May awarded two contracts to "support the
production and clinical testing of an investigational
vaccine based on [H5N1] which might have the potential
to cause pandemic influenza". The awards went to Aventis
Pasteur Inc and the Chiron Corporation, the latter being
the firm that produced the human influenza vaccine that
recently has been designated unusable. Kalus Stohr, the
head of WHO's influenza program, stated this month that,
"nobody would have a vaccine if the pandemic comes in
two months, and very very few people would have a
vaccine in four months".
Bruce
Klingner is director of analysis for Intellibridge
Corp in Washington, DC. His areas of expertise are
strategic national security, political and military
affairs in China, Northeast Asia, Korea and Japan. He
can be reached at bklingner@intellibridge.com.
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