Sunday, January 13, 2013

(Presumably) LPAI H5N1 Found In New York


Photo Credit – FAO


# 6851


On Friday a small news item appeared in the National Chicken Council’s Washington Report indicating that (presumably Low Pathogenic) H5N1 avian influenza had been detected at a New York live bird market, resulting in a halt of poultry exports to Japan & Taiwan.


Avian Influenza Found in New York Live Bird Market; Japan and Taiwan Halt Poultry Exports from New York

On January 11, 2013, in Avian Influenza

USDA’s National Veterinary Services Laboratories has confirmed H5N1 (presumably low pathogenic) from a live bird market in New York . . .


While quite common in other countries, many Americans may be surprised to know that there are more than 90 live bird markets in and around New York (cite Cornell University).  Live markets can also be found in other states as well.


The newshounds at FluTrackers have been all over this story since early yesterday (see thread), but there’s been nothing new reported over the weekend.  Sharon Sanders put in a call to the National Chicken Council yesterday, unfortunately their offices are closed until Monday.


ProMed Mail issued an alert overnight AVIAN INFLUENZA, H5N1, LPAI - USA: (NEW YORK) POULTRY, REQUEST FOR INFORMATION, from a news item submitted by Gert van der Hoek at FluTrackers.


As you might expect, there is a certain degree of frustration in Flublogia this weekend over the lack of details available on this story.


There are two broad categories of avian influenza; LPAI (Low Pathogenic Avian Influenza) and HPAI (Highly Pathogenic Avian Influenza).


  • LPAI viruses are quite common in wild birds, cause little illness, and only rarely death.  They are not considered to be a serious health to public health. The concern is (particularly with H5 & H7 strains) that LPAI viruses have the potential to mutate into HPAI strains.
  • HPAI viruses are more dangerous, can produce high morbidity and mortality in wild birds and poultry, and can sometimes infect humans with serious result. The type of bird flu scientists have been watching closely for the past decade has been HPAI H5N1 (and to a lesser extent HPAI H7s & H9s).


Before the middle of the last decade, there was no uniform requirement to report or track LPAI infections.  That changed in 2006 when the OIE made reporting of LPAI H5 & H7 viruses mandatory.


LPAI H5N1 has been detected before across North America, and a partial list (from the USDA Release No. 0296.06) Includes:


LPAI H5N1 ("North American" H5N1)

LPAI, or "low path" AI, commonly occurs in wild birds. In most cases, it causes minor sickness or no noticeable signs of disease. It is rarely fatal in birds. LPAI strains are not a human health concern. This includes LPAI H5N1.


Evidence of LPAI H5N1 has been found in wild birds in the United States in recent years and is not closely related to the more severe HPAI H5N1 circulating overseas. Examples of historical reports of LPAI H5N1 received by USDA include:


  • 1975 - LPAI H5N1 was detected in a wild mallard duck and a wild blue goose in Wisconsin as part of routine sampling, not as a result of noticeable illness in the birds
  • 1981 and 1985 - the University of Minnesota conducted a sampling procedure in which sentinel ducks were monitored in cages placed in the wild for a short period of time and LPAI H5N1 was detected in those ducks in both years.
  • 1983 - LPAI H5N1 was detected in ring-billed gulls in Pennsylvania.
  • 1986 - LPAI H5N1 was detected in a wild mallard duck in Ohio as part of routine sampling, not as a result of noticeable illness in the birds.
  • 2002 - LPAI H5N1 antibodies were detected in turkeys in Michigan but the virus could not be isolated; therefore this detection could not be confirmed.
  • 2005 - LPAI H5N1 was detected in ducks in Manitoba, Canada.
  • 2006 - LPAI H5N1 was confirmed in two Michigan mute swans and mallard ducks; Maryland resident wild mallard ducks, and Pennsylvania wild mallard ducks; and Delaware green-winged teals, all sampled as part of USDA's expanded avian influenza surveillance.  


Another, more current list, is available on FluTrackers, with nearly 20 LPAI detections reported between 2006-2013 in the United States.


The discovery of LPAI H5N1 in the United States is neither unusual, nor is it a public health concern.  But as LPAI viruses can be progenitors of more virulent HPAI strains, steps will have to be taken to contain and eradicate this virus.


Hopefully we’ll get more information on the location and extent of this detection, and some details on the steps being taken to contain it over the coming days. While I’ll update this story, the latest news is likely to be found on this FluTrackers thread first.

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