Affordable Access

Infectious Disease: ExPECting the Worst

Environmental Health Perspectives
Environmental Health Perspectives
Publication Date
  • Environews
  • Forum
  • Medicine
  • Political Science


workingforum The earth is the very quintessence of the human condition. Hannah Arendt (1906–1975) Environews Forum A 370 VOLUME 113 | NUMBER 6 | June 2005 • Environmental Health Perspectives On Hens and Needles Asian governments alarmed at the unprece- dented spread of the deadly H5N1 avian influenza virus are seeking relief in a con- troversial vaccination program. The Thai government announced in February 2005 that it would join China and Indonesia in vaccinating select healthy ducks and chick- ens. Vietnam also is considering a vaccina- tion program. Vaccinations can lessen the risk of influenza by reducing the birds’ chances of infection and minimizing the amount of virus shed through nasal secretions and feces by those that do become infected. But vaccinated chickens can still become infected while showing no symptoms of disease (chickens that have not been vaccinated typically die within 48 hours of infection). For that reason, many countries— including Japan, one of Thailand’s biggest poultry markets—ban imports of vaccinated chickens. Countries therefore usually vacci- nate poultry against influenza only as a last resort. “The concern is that if a vac- cine is used, it will be harder to identify the virus,” says epidemiol- ogist Mark Katz of the Centers for Disease Control and Prevention, “and it’s not a guarantee that vacci- nation will completely eliminate the shedding of virus.” Asian farmers, though, are run- ning out of options. Mass culling has done little to stem the epidem- ic. More than 120 million chickens in Vietnam, Thailand, and China died or were destroyed during a three-month period early in 2004. A 2 September 2004 article in Nature says many Thai farmers are turning to ineffective black-market vaccines to avoid killing their birds. But black-market vaccines can contain viruses that have not been properly inactivated, and may spur the evolution of even more danger- ous strains. Moreover, the virus poses the serious threat of sparking a world- wide hum

There are no comments yet on this publication. Be the first to share your thoughts.


Seen <100 times