# 2443
Like most Americans, I was up way too late last night watching the election returns, on top of which, I'm battling what appears to be a cold - so my Nyquil affected commentary will be mercifully short this morning.
The current issue of the CDC's journal of Emerging Infectious Diseases has an interesting study on the prevalence of the H5N1 virus among birds sold in live markets in Thailand.
Thailand last recorded a human infection with the H5N1 bird flu virus in September of 2006. This study, which ran from July of 2006 to August of 2007, detected the virus in live markets long after that last human case was reported.
Of 930 samples taken over a 14 month period, 12 (1.3%) tested positive for the H5N1 virus.
Positive samples, however, were only found during the 3 month winter season (Nov-Jan), which would mean the actual percentage of infected birds in the marketplace during that time span was probably considerably higher.
All of this points to how difficult it is to contract the virus, even when it is in the environment.
Sellers and buyers alike were obviously exposed to infected birds in these markets, and on the farms where these birds were raised. Yet no human cases appeared in Thailand during this time.
Live markets, of course, have been linked to human infection in the past. They remain a crossroads where potentially infected birds can come in contact with a large number of humans, and as such are worrisome.
The authors of this study recommend year-round monitoring of live markets in countries where such markets are commonplace.
Below are some pertinent excerpts from the study (reparagraphed for readability).
Follow the link to read it in its entirety.
Volume 14, Number 11–November 2008
Dispatch
Influenza Virus (H5N1) in Live Bird Markets and Food Markets, Thailand
Alongkorn Amonsin, Chuensakon Choatrakol, Jiradej Lapkuntod, Rachod Tantilertcharoen, Roongroje Thanawongnuwech, Sanipa Suradhat, Kamol Suwannakarn, Apiradee Theamboonlers, and Yong Poovorawan
Author affiliation: Chulalongkorn University, Pathumwan, Bangkok, ThailandAbstract
A surveillance program for influenza A viruses (H5N1) was conducted in live bird and food markets in central Thailand during July 2006–August 2007. Twelve subtype H5N1 viruses were isolated. The subtype H5N1 viruses circulating in the markets were genetically related to those that circulated in Thailand during 2004–2005.
In Thailand, from 2004 through 2008, 6 major outbreaks of avian influenza occurred (January–March 2004, July–October 2004, October–December 2005, January–March 2006, November–March 2007, and January 2008). We report on a 14-month avian influenza surveillance program and its finding of influenza virus (H5N1) in live bird and food markets in Thailand.
<snip>
Conclusions
In the course of the 14-month surveillance program, we isolated influenza virus (H5N1) from 12 samples from live birds and from bird meats obtained from the markets.
Bird meats were the source of 9 virus-containing samples (5 quail, 2 moor hens, and 2 water cocks), which indicates a risk for influenza virus (H5N1) contamination in bird meats, especially quail. In addition, 3 highly pathogenic avian influenza viruses were isolated from healthy live poultry (1 chicken and 2 ducks).
< snip>
It has been known that live bird and wet markets play a major role in facilitating emergence or reemergence of influenza and some other respiratory diseases (10–12).
Monitoring of live bird and food markets as an early warning system should be implemented in Asian countries where such markets are still commonplace, and routine surveillance of these markets should be conducted year-round.
In addition, raw bird meats should be handled with caution, and consumption of raw bird meats should be avoided. Increased public awareness about the risks for influenza virus (H5N1) in association with live bird and food markets will help prevent and control subtype H5N1 infection in humans
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