Hong Kong Avian Flu Outbreak in 1997

In late 1997 and early 1998, Hong Kong became embroiled in an enlightening and tragic health crisis that saw the first case of Avian Flu crossing the bird-to-human species barrier with devastating consequences.

It is speculated that the Hong Kong Avian Flu outbreak originated from the New Territories Region in northern Hong Kong.  In this area, chickens had been dying and routine testing of poultry had verified the presence of the Avian Flu virus – subtype H5N1.  This subtype would be well known by the time the whole outbreak was declared over.   

The first case of Avian Flu in humans was a young three-year-old boy in May, 1997.  It was unknown what had caused his grave illness for some time.  The boy had severe respiratory failure and was in great pain up to his death.  Initial tests failed to show anything.  If the culprit was the Influenza virus, then it didn't react with any of the standard lab tests used to identify influenza virus.  By August, the boy's specimen had been identified as a type of influenza never before seen in human beings.  Tests had shown that the boy had a Type A Influenza virus H5N1.  The news was a shock to the medical and health community because H5N1 was a Bird (Avian) Flu subtype, and had not been known to infect a human being.  

Epidemiologists began to unravel the mystery once they became aware of the Avian Flu outbreaks in the Northern Hong Kong.  Investigators found out that the boy had attended a day care and the teachers had kept chicks as playthings for the children.  Some of the birds had died.  None now remained, so no testing of the animals was possible.  However, there were still many questions that needed to be answered for the Avian Flu to be the clear culprit. 

Three months later, another Avian Flu case was reported.  By December, there were more and more cases of Avian Flu cases in humans reported.  Each of these humans had Avian Flu subtype H5 detected in them.  Investigators went out to determine the source of infection.  Their preliminary results were at first puzzling: There was relatively little overlap among the flu victims, and there were no signs that the flu was passed from humans to humans.  Veterinarians had detected the H5N1 virus in dying chickens at a recent outbreak, but none of the infected patients had visited that region.  However, the one connection between them was that most of them had visited a local live poultry market the week before falling ill.           

With further investigation, health department officials found a chilling and disturbing new breakthrough.  In studies conducted from samples of bird feces and blood from the nation’s poultry markets, the H5N1 Avian Flu subtype was detected.  Indeed, it had appeared that the infamous virus had spread throughout the nation's live poultry markets.

Health organizations including the Center of Disease Control had made their recommendations to Hong Kong authorities – slaughter every bird within its border.  The evidence presented was clear: Since May, avian flu had affected birds in a small region of the nation.  By December, the infection was widespread in farms across the tiny island.  Understandably, government officials were hesitant of this major action.  If chicken markets were not the direct cause of this outbreak, killing poultry would be an enormous economic waste.  But with every new case reported of humans infected with Avian flu, there was mounting pressure on the government to do something to prevent further spread of the disease.  At this time, four people had died from the Avian Flu.         

Hong Kong’s Agriculture, Fisheries and Conservation Department officials began organizing a nationwide cull of all domestic poultry in the island nation including chickens, ducks, geese, quails, and pigeons, which would be initiated within a few days.  The massive undertaking to destroy every chicken in Hong Kong involved as many as 2,000 workers from at least seven government agencies.  They went about conducting their duties in Hong Kong’s 160 chicken farms and about 1000 live poultry markets.  The cull was extended to all poultry at retail and wholesale outlets.

By the time the cull was completed, approximately 1.5-million birds were slaughtered to minimize the spread of Avian Flu.  It was deemed widely successful as overnight, new human infections had ceased.  However, there would be several new cases.  At the end of the whole fiasco by March, 1998, when the government stated that it had controlled the outbreak of the disease, there were 18 people who had fallen ill to the Avian Flu, of which, 6 tragically died.   

Now that they had controlled the outbreak, Hong Kong had decided to reopen its border to Mainland China – they had closed it for over the previous month during their mass culling.  Many health officials saw this action as just another invitation for another future disaster.  Hong Kong widely suspected China as being the source of the virus.  China refuses to officially acknowledge that it has an H5N1 problem.  But documents prior to the 1997 outbreak revealed that China's Ministry of Health was requesting from the World Health Organization H5N1 reagents, which are used to test for presence of antibodies to the virus.  This suggest (although not confirmed), at the very least, that China suspected this type of influenza might be afflicting its poultry but did not yet have the means to test.