Useful Fools

Posted By John Moore on January 23, 2004

The World Health Organization is becoming seriously alarmed at a “historically unprecedented” epidemic of the most dangerous (to humans) strain of Avian Influenza. Their 22 January 2004 bullten is titled: “Avian influenza H5N1 infection in humans: urgent need to eliminate the animal reservoir – update 5″. The full bulletin is at the end of this entry. The reason for their concern is that if H5N1 “crossbreeds” with a human flu, the result could be a human epidemic of a very deadly flu like the one that killed 500,000 people in the United States, and 20 to 40 million worldwide in 1918.

Selected quotes:

The current situation is of serious concern for human health as well as for agriculture and the poultry industry. Rapid elimination of the H5N1 virus in bird populations should be given high priority as a matter of international public health importance.

Of all the avian influenza viruses, which normally cause infection in birds and pigs only, the H5N1 strain may have a unique capacity to cause severe disease, with high mortality, in humans.

Note: The previous post on this blog implied that China was covering up Avian Influenza H5N1 infections in Guangdong. At this point, China is actively cooperating with WHO and may not have been aware of H5N1 infections at the time it exported H5N1-tainted meat. However, it did cover up SARS for several months in 2002-2003.

UPDATE from Pro-Med:

WHO Asks China to Account for 2 Tourist Deaths in Early 2003
————————————————————
China is facing allegations it may have been the source of the Asia-wide
bird flu outbreak, with the World Health Organisation seeking an
explanation of the deaths of 2 Hong Kong tourists a year ago.

The British weekly New Scientist said it believes the outbreak began in
southern China in early 2003, allegedly after a poultry vaccination scheme
went wrong. The report has put the spotlight back on the 2 tourists who
died after visiting southern China in February 2003. The WHO has asked the
Chinese government for more information as part of efforts to establish the
history of the bird flu outbreak which has been detected in 10 Asian nations.

WHO BULLETIN:

Avian influenza H5N1 infection in humans: urgent need to eliminate the
animal reservoir – update 5
22 January 2004

Epidemics of highly pathogenic avian influenza, caused by various H5N1
strains, have been reported in parts of Asia since mid-December 2003.
Millions of domestic poultry have either died or been destroyed as a result.
Thousands of workers have been involved in the culling operations.

The current situation is of serious concern for human health as well as for
agriculture and the poultry industry. Rapid elimination of the H5N1 virus in
bird populations should be given high priority as a matter of international
public health importance.

WHO is collaborating closely, at high levels, with FAO and the World
Organisation for Animal Health (OIE) to ensure that appropriate measures in
the agricultural sector are introduced as a matter of urgency, and in the
interest of protecting public health at the international level. Joint
investigations are currently under way in Viet Nam.

Of all the avian influenza viruses, which normally cause infection in birds
and pigs only, the H5N1 strain may have a unique capacity to cause severe
disease, with high mortality, in humans.

The simultaneous occurrence in several countries of large epidemics of
highly pathogenic H5N1 influenza in domestic poultry is historically
unprecedented. The present situation may grow worse. In bird populations,
the disease is highly contagious and rapidly fatal, and spreads easily from
farm to farm. Wild migratory waterfowl can spread infection to domestic
flocks. The potential for further spread of ongoing poultry epidemics, both
within affected countries and to other countries, is therefore great.

For all these reasons, the H5N1 strain may be more widely established in
bird populations and in the environment in this part of the world than
presently appreciated. Studies have shown that infected birds can shed large
amounts of the virus in their faeces. The virus can survive for long periods
in the tissues and faeces of diseased birds and in water, especially when
temperatures are low. In water, the virus can survive for up to four days at
22oC and more than 30 days at 0oC. The virus survives in frozen material
indefinitely.

The large epidemics of highly pathogenic avian influenza currently seen in
poultry, and possible widespread presence of the virus in the environment,
increase opportunities for human exposure and infection. They also increase
opportunities for human and avian influenza viruses to exchange genes This
can occur when humans are simultaneously infected by human and avian
influenza viruses. The frequency of such co-infections increases the
likelihood that a completely new influenza virus subtype might emerge,
carrying sufficient human genes to allow efficient and sustainable
person-to-person transmission.

Research has shown that the risk of direct transmission of H5N1 infection
from birds to humans is greatest in persons having close contact with live
infected poultry. Contact with poultry kept in live markets is considered
the source of infection for 17 of the 18 human cases of H5N1 infection that
occurred in Hong Kong in 1997. The additional case – the first in the
outbreak – has been linked to contact with poultry at farms experiencing
epidemics of highly pathogenic avian H5N1 influenza. Six of the 18 cases
were fatal.

Occupational exposure can occur among poultry workers, and among workers
involved in culling operations.

Rapid elimination of the H5N1 virus in animal populations is an essential
measure to prevent the emergence of a new influenza virus subtype with
pandemic potential. This measure not only helps prevent further spread in
bird populations, but also reduces opportunities for human infection.
However, in the present situation, the problem of controlling all human
exposures is compounded by the large number of “back yard” farms where
chickens are kept in rural areas.

While rapid culling of infected or exposed flocks is strongly recommended,
prevention of infection during culling operations must also be given high
priority. Culling operations can place large numbers of workers at risk of
brief but intensive exposure to the virus.

In 1997, Hong Kong authorities culled the entire poultry population, an
estimated 1.5 million birds, within three days. This rapid and comprehensive
action is thought by many experts to have averted an influenza pandemic.
Culling operations were performed by trained government workers, most of
whom wore protective masks, gloves, and gowns. Although subsequent
investigation detected H5 antibodies, indicating exposure to the virus, in
around 3% of persons involved in the culling of infected poultry, no case of
severe respiratory disease was detected as a result of this exposure.

In the Netherlands in 2003, an outbreak of highly pathogenic H7N7 avian
influenza in poultry caused infection, with mild illness, in 83 persons, and
fatal illness in a veterinarian. An estimated 30 million poultry were culled
within a week.
Further information about highly pathogenic avian influenza is available in
a WHO fact sheet, at the FAO web site
, and the OIE
web site .

Information on safety precautions during culling operations will be issued
soon by the WHO Regional Office for the Western Pacific.

Laboratory characterization of the 2004 H5N1 viruses
Laboratories in the WHO Global Influenza Surveillance Network have today
discussed results from the sequencing and antigenic characterization of H5N1
strains isolated from humans and poultry in Viet Nam. Initial results show
significant differences between these viruses and strains obtained during
outbreaks of H5N1 avian influenza in Hong Kong, in 1997 and 2003, indicating
that the virus has mutated.

Work continues on the updating of WHO diagnostic kits for the rapid
detection of H5N1 infection in humans, and on the development of a prototype
virus for use in vaccine manufacturing. Viruses from birds in other
currently affected countries are urgently needed in order to conduct
additional laboratory investigations. Such investigations are part of the
information needed by WHO to recommend and develop a vaccine strain that can
protect humans against circulating H5N1 strains.

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