Monday, December 06, 2010

NWHC: Global Avian Influenza Update

 

 

 

# 5118

 

 

The National Wildlife Health Center (NWHC) division of the USGS maintains an avian influenza information page that they update at irregular intervals.

 

The latest update came on Friday, December 3rd, and it contains a roundup of recent outbreaks and a discussion of a report on the raising of bar-headed geese in China, and how that might be contributing to the spread of H5N1.

 

I’ve only excerpted (and reparagraphed for readability) the section on the raising of geese.

 

In addition you’ll find capsule reports on recent avian influenza outbreaks among poultry from Japan, Georgia, Vietnam, Canada (LPAI), and  Germany (LPAI).

 

Avian Influenza Information


News Update, December 3

H5N1 in Wild birds
China
. Researchers believe that captive rearing of bar-headed geese in China provides a possible scenario for the emergence of the Qinghai Clade 2.2 bird flu virus and its occurrence in wild birds.

 

The first outbreak of H5N1 bird flu at Lake Qinghai occurred in 2005 and killed more than 6,000 birds, including more than 3,000 bar-headed geese. More outbreaks of bird flu all involving bar-headed geese occurred in the same area in 2006, 2007, 2009, and 2010.

 

It has been reported that there was little domestic poultry production in the areas surrounding these outbreaks. The authors of a letter to the Journal of Wildlife Disease (see citation below) discovered that raising bar-headed geese in captivity was practiced extensively in this region of China, raising the possibility of contact with wild birds.

 

Bar-headed geese have been raised in China since 2003 both for their meat and to supplement the declining wild population. The birds are often kept in close contact with domestic poultry and may have become infected with bird flu through them. At other times they graze outdoors with wild birds and could have transmitted the disease to wild flocks.

 

The authors found no direct evidence that captive rearing of bar-headed geese was involved in the outbreaks in the Qinghai lake area, but they believe the possibility deserves scientific study.

<SNIP>

H5N1 in the Scientific Literature

  • Feare CJ et al. Captive Rearing and Release of Bar-headed Geese (Anser indicus) in China: A Possible HPAI H5N1 Infection Route to Wild Birds. J Wildl Dis. 2010;46(4):1340-2.
  • Indriani R et al. Environmental Sampling for Avian Influenza Virus A (H5N1) in Live-Bird Markets, Indonesia. Emerg Infect Dis 16(12):1889.
  • Potapova OV et al. Structural Changes in the Brain of Mice Infected with Influenza A/H5N1 Virus. Bull Exp Biol Med. 2009 Dec;148(6):892-5.

Other publications of interest

  • Dos Reis M et al. Charting the host adaptation of influenza viruses. Mol Biol Evol. 2010 Nov 25. [Epub ahead of print]
  • Hansbro PM et al. Surveillance and Analysis of Avian Influenza Viruses, Australia Emerg Infect Dis 16(12):1896.