Avian Flu Returns To China. Did It Come From the U.S.?

English: Avian Influenza ( Bird Flu ) Sign Avi...
English: Avian Influenza ( Bird Flu ) Sign Avian influenza (bird flu) sign at the junction of the A140 and the B1078. This has become the entrance to the restricted zone more info see http://www.bbc.co.uk/suffolk/content/articles/2007/02/05/bird_flu_holton_reaction_feature.shtml other side of the sign see http://www.geograph.org.uk/photo/338388 (Photo credit: Wikipedia)

The New York Times announced a new outbreak of the avian flu in Shanghai, with six dead. The new mutation, H7N9, is a different bird than the two recent mutations H1N1 and H5N1, so yes, you can get it even if you’ve had the flu shot and both the other illnesses.

The news will be full of Chinese hazmat workers toting bags of dead chickens for the next few days, and we’ll all get our “zombie apocalypse” dose of CDC alarm. But before we fall into the trap of looking to China as the infectious disease epicenter of this year’s avian flu, I’d like to point out an inconvenient little piece of data.

When looking at trends of avian flu outbreaks, particularly H7N9, clearly this went through the U.S. in 2011. Many different birds were affected, including “chickens, turkeys, geese, and guinea fowl.” So if this went through the U.S. in 2011, we’ve got our own exposures and infection sites.

If you go further back, we’ve had various outbreaks of avian influenza with many different subtypes over that last decade.  The majority of these didn’t really make a newsblip.

As you watch the parade of garbage bagged chickens in Shanghai, keep in mind that the six deaths from H7N9 pale in comparision to the deaths yearly in the U.S. from regular old influenza.  Time to keep a little perspective on the outbreak.

Avian Dis. 2012 Dec;56(4 Suppl):845-8.

Avian influenza in North America, 2009-2011.


Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, 1015 Arlington Street, Winnipeg, Manitoba, Canada R3E 3M4. John.Pasick@inspection.gc.ca


All reports of avian influenza virus infections in poultry and isolations from wild bird species in Canada, the United States, and Mexico between 2009 and 2011 involved low pathogenic avian influenza. All three countries reported outbreaks of low pathogenic notifiable avian influenza in poultry during this period. The reports involved outbreaks of H5N2 among commercial turkeys in Canada in 2009 and 2010; outbreaks of H5N3 in turkeys in 2009, H5N2 in chickens in 2010, H7N3 in turkeys in 2011, and H7N9 in chickens, turkeys, geese, and guinea fowl in 2011 in the United States; and multiple outbreaks of H5N2 in chickens in Mexico in 2009, 2010, and 2011. Outbreaks of pandemic H1N1 infections in turkey breeder flocks were reported in Canada in 2009 and in the United States in 2010. Active surveillance of live bird markets in the United States led to the detection of H2, H3, H4, H5, H6, and H10 subtypes. Despite the fact that wild bird surveillance programs underwent contraction during this period in both Canada and the United States, H5 and H7 subtypes were still detected.

Avian Dis. 2010 Mar;54(1 Suppl):179-86.

Avian influenza in North and South America, the Caribbean, and Australia, 2006-2008.


U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, National Veterinary Services Laboratories, Ames, IA 50010, USA. dennis.a.senne@aphis.usda.gov


Between 2006 and 2008, only one outbreak of highly pathogenic notifiable avian influenza (AI) was reported from the Americas, the Caribbean, and Australia. The outbreak, caused by H7N3, occurred in September 2007 in a multiage broiler breeder facility (approximately 49,000 birds) near Regina Beach in southern Saskatchewan, Canada. The disease was confined to a single farm; the farm was depopulated. All other reports of infections in poultry or wild birds involved low pathogenicity AI viruses. A notable event that occurred during the 3-yr period was the spread of low pathogenicity notifiable AI (LPNAI) H5N2 (Mexican lineage) into the Caribbean countries of the Dominican Republic and Haiti in 2007 and 2008, respectively, representing the first detection of AI reported in these countries. Mexico reported that the LPNAI H5N2 virus continued to circulate in the central regions of the country, and a total of 49 isolations were made from 12 states between 2006 and 2008. Also, during this period there was a significant increase in AI surveillance in many countries throughout the Americas, the Caribbean, and Australia, resulting in the detection of AI subtypes H1 through H12 and N1 through N9 in domestic bird species (chickens, turkeys, guinea fowl, upland game birds, and ducks/geese). The United States was the only one of these countries that reported detections of LPNAI (H5 or H7) infections in commercial poultry: one in chickens (H7N3, 2007), two in turkeys (H5N1 and H5N2, 2007), and one in pheasants (H5N8, 2008). Detections of AI viruses in wild birds between 2006 and 2008 were reported from North America (Canada and the United States), South America (Bolivia, Argentina, Chile, and Brazil), and Australia.


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