BANGKOK, Thailand, September 30, 2004 (ENS):
Thai health officials are investigating the first possible
human-to-human transmission of a highly virulent form
of avian influenza, and countries across Asia are scrambling
to prepare for another outbreak of the deadly virus.
An 11 year old girl and her mother both died since early
September. Officials believe the mother was infected
while caring for her daughter, and that this is a probable
case of human-to-human transmission.
"Such a situation would be cause for alarm, as
it might signal the start of an influenza pandemic,"
warned the Ministry of Public Health in Thailand. Still,
evidence to date indicates that transmission of the
virus among humans has been limited to family members
and that no wider transmission in the community has
Altogether, Thailand has reported 15 cases, of which
10 were fatal, since the first human cases were detected
in January of this year. Health officials confirm that
these people were infected with the avian influenza
A (H5N1) virus, the same viral strain that caused 23
deaths and the slaughter of at least 100 million birds
in an outbreak across Asia last winter and spring.
The avian influenza epidemic in Asia is a "crisis
of global importance" and will continue to demand
the attention of the international community, the UN
Food and Agriculture Organization (FAO) and the World
Organization for Animal Health (OIE) are warning.
Recent outbreaks in China, Vietnam, Cambodia, Malaysia
and Thailand show that the virus continues to circulate
in the region and will not probably be eradicated in
the near future, the two organizations said in a joint
statement on Monday.
On Monday, the Ministry of Health of Vietnam has confirmed
that the death of a 14 month old boy early this month
was caused by the same viral strain. This is the third
death from the virus in Vietnam since August. The baby
in Hanoi had typical symptoms of avian influenza virus
infection, including fever and cough.
China has required all localities to strengthen preventive
efforts against a possible outbreak of the highly pathogenic
bird flu, during autumn 2004 and winter 2005, according
to a new circular issued by the Ministry of Agriculture.
"Since the autumn and winter period is a key period
for birds to migrate, the bird flu is quite likely to
break at any time," warns the circular, which cites
the ongoing bird flu in other Asian countries as a threat
More research is urgently needed as the role of wildlife,
domestic ducks and pigs in transmitting the virus among
animals is still not fully understood, the FAO and OIE
warned. "A permanent threat to animal and human
health continues to exist," they said.
While much progress has been made in early detection
and reaction, countries still need to step up proactive
surveillance and control measures. Major investments
are required to strengthen veterinary services, in particular
for surveillance, early warning, detection, reporting
and response and for the rehabilitation and restructuring
of the poultry sector, the agencies said.
The newly published FAO Recommendations on the Prevention,
Control and Eradication of Highly Pathogenic Avian Influenza
in Asia, prepared in close collaboration with the OIE,
review the factors that should be taken into account
in designing and implementing control programs and explain
how countries can adopt a strategy appropriate to their
In response to recent controversies on vaccination
against bird flu, the two agenices reiterated that the
slaughter of infected animals is the best way of controlling
and ultimately stamping out the disease.
But officials acknowledged that this policy may not
be practical or adequate in certain countries because
of social and economic reasons or because of high viral
challenge due to infection in villages, wild birds or
domestic waterfowl. In such cases, countries wishing
to eradicate the disease may choose to use vaccination
as a complementary measure to the stamping out policy.
China's bird flu control policy is based mainly upon
mass preventative vaccination. "Authorities should
also prepare and improve their emergency plans and ready
vaccine and sterilizing drugs," says the Ministry
of Agriculture circular.
The two agencies stressed that vaccines, if used, should
be produced in accordance with the international guidelines
prescribed in the OIE Manual of Diagnostic Tests and
Vaccines for Terrestrial Animals.
The OIE Terrestrial Code states that a country may
be considered free from highly pathogenic avian influenza
based on the absence of virus irrespective of whether
vaccination has been carried out. The two organizations
confirmed that the use of vaccines does not imply automatic
loss of export markets.
It has been shown that the use of such vaccines does
not only protect healthy birds from disease but also
reduces the load of viruses excreted by infected birds
and cuts the likelihood of transmission of the virus
to other birds and to humans.
The decision on whether to use vaccines has to be made
by each country based on its own situation, the two
The factors countries should consider in making their
decision include their ability to detect and react to
the disease as early as possible and the need for transparent
and timely notification. This will have to be supported
by a good institutional framework and sound legislation
underpinning veterinary services.
Any vaccination strategy should be developed in consultation
with all stakeholders, including the private sector.
The types of poultry and production sectors to be vaccinated
must be determined and clearly documented. Infected
poultry and those in contact with the virus should not
The two agencies said vaccination should be carried
out under the supervision of official veterinary services
and be accompanied by a parallel surveillance strategy.
This would include the capacity of the veterinary services
to identify and monitor the circulating virus as well
as the response to vaccination, by means including the
use of non-vaccinated sentinel birds and the application
of serological tests capable of differentiating infected
from vaccinated animals.
The World Health Organization's Southeast Asia Regional
Office says, "The risk of emergence of a new influenza
virus due to genetic modifications, which could trigger
an outbreak with pandemic potential, remains real as
long as the avian influenza virus continues to circulate
in the environment."
It appears that the virus will continue to stay in
the environment in the foreseeable future so WHO officials
emphasized the need for enhanced and sustained surveillance.
Copyright Environment News Service (ENS) 2004. All