A Messy Story - The Monster at Our Door: The Global Threat of Avian Flu - page 27

Meanwhile, H5N1 was again laying siege to Hong Kong. Between February and March 2001, the
surveillance network found several strains of the virus among market chickens, quail, pheasants, and pi-
geons. A few months later, South Korean authorities isolated H5N1 in imported Chinese duck meat. Lab-
oratory testing subsequently revealed that these H5N1 genotypes were a separate reassortment from the
1997 strain and had most likely originated sometime in late 2000 from goose viruses that had “crossed to
ducks and re-assorted with other unknown influenza viruses of aquatic origin.” Researchers were horri-
fied to discover that the new H5N1 was even more pathogenic than the old: when mice were infected with
the 2001 strains, the virus spread to the brain and killed the animals. In May chickens started dying again
in the city's markets, and once more the city government mandated a slaughter of local poultry before the
new strains infected humans or reassorted with H9N2. 106
With so much heavy genetic traffic between feral avian reservoirs, domestic poultry, and mammals,
researchers were becoming pessimistic about the likelihood of successfully containing further outbreaks
by local culling of birds. When H5N1 returned again in February 2002, top virologist Yi Guan of the
University of Hong Kong told China Daily that truly drastic action was now necessary—live poultry
had to go. Guan said, “I believe that we have to get rid of the farms, and the poultry markets, and
the import of fresh chickens.” The poultry industry—seemingly oblivious to the nature of the pandemic
threat—screamed that the scientists had gone berserk. “Avian influenza is just like any human flu—you
just cannot get rid of it. However, it does not make sense to get rid of the poultry industry to get rid of
the bird flu. That would be an ignorant act.” 107 The authorities seemingly agreed, and they restricted their
response to ordering the destruction of another 900,000 chickens.
In December, textbook theory was again confounded as H5N1 began to decimate its natural hosts.
Ducks, as well as geese, flamingos, swans, egrets, and herons, started dying in two popular Hong Kong
parks; mallards—presumed immune to the pathogenic effects of influenza—developed catastrophic neur-
ological disorders. The dead ducks were incontrovertible proof that a two-way flow of H5N1 mutants now
existed between aquatic and terrestrial birds. Researchers who studied the outbreak were troubled by the
theoretical implications:
A pathogenic H5N1 outbreak among waterfowl and wild birds is therefore novel and has serious
implications. . . . Previous phylogenetic studies had shown low evolutionary rates of avian influ-
enza viruses in waterfowl. Therefore, it was generally accepted that influenza viruses were in evol-
utionary stasis in wild aquatic birds, with no evidence of clear evolution over the past 60 years.
The data presented in this paper raise the possibility that this balance may be changing in ducks
or that it has been disrupted by the introduction of novel viruses to ducks from some other avian
source. 108
Scientists worried that antigenic drift had been accelerated by the illegal use of unregistered poultry
vaccines in Guangdong. Other researchers speculated that lethal strains of H5N1 might spread through
the wild duck population and follow the annual migration back to Siberian or even Alaskan lakes. 109 (In
2004, the United Nations' Food and Agriculture Organization [FAO] learned that Russian researchers in
Novosibirsk had indeed found H5N1—95 percent similar to the Hong Kong strain—the previous year in
a wild mallard duck on Lake Chany in western Siberia.) 110 In any event, as Shortridge, Peiris, and Guan
glumly pointed out in an article, it was now evident that the H5N1 infection in birds had become “non-
eradicable.” 111 Meanwhile, Hong Kong closed its parks and slaughtered its beloved wild birds.
Two months later, at the beginning of February 2003, a seven-year-old girl died of an acute respiratory
disease while visiting a Fujian province in the company of her mother, sister, and brother. She was buried
before the exact cause of death could be ascertained. Her father, who rushed from Hong Kong to his dying