Influenza A(H5N1) Virus Surveillance at Live Poultry Markets, Cambodia, 2011 - Vol. 19 No. 2 - February 2013 - Emerging Infectious Disease journal - CDC

full-text ►
Influenza A(H5N1) Virus Surveillance at Live Poultry Markets, Cambodia, 2011 - Vol. 19 No. 2 - February 2013 - Emerging Infectious Disease journal - CDC

Georges de La Tour (1593‒1652) La Femme à la puce (The Flea Catcher) (1638) Oil on canvas (90 cm × 120 cm) Musée Lorrain, Nancy. Photo P. Mignot

Volume 19, Number 2—February 2013

Dispatch

Influenza A(H5N1) Virus Surveillance at Live Poultry Markets, Cambodia, 2011

Article Contents

• The Study


• Conclusions


• Acknowledgment


• References


• Figure 1


• Figure 2


• Table


• Suggested Citation

Srey Viseth Horm, San Sorn, Lotfi Allal, and Philippe Buchy 

Author affiliations: Author affiliations: Institut Pasteur, Phnom Penh, Cambodia (S.V. Horm, S. Sorn, P. Buchy); Ministry of Agriculture, Phnom Penh (S. Sorn); Food and Agriculture Organization, Phnom Penh (L. Allal)

Suggested citation for this article

Abstract

In Cambodia, influenza A(H5N1) virus surveillance at live poultry markets (LPMs) relies on virus isolation from poultry specimens; however, virus is rarely detected by this method. We tested 502 environmental LPM samples: 90 were positive by PCR, 10 by virus isolation. Virus circulation could be better monitored by environmental sampling of LPMs.

Highly pathogenic avian influenza (HPAI) A(H5N1) virus was first detected in 2004 in Cambodia. Since then, outbreaks of subtype H5N1 infection among poultry have been regularly detected, and 21 human cases associated with 19 deaths have been recorded (1).
In Cambodia, where poultry vaccination is not allowed, illegal poultry trade has been a repeated source of reintroduction of the virus (2–4). Surveillance for subtype H5N1 virus at live poultry markets (LPMs) has been conducted in Cambodia by inoculating cloacal or throat swab specimens from poultry into embryonated chicken eggs; however, virus has rarely been detected by this method (S. Sorn, unpub. data). After outbreaks of subtype H5N1 virus in poultry, the viral genome can be detected for >1 week in environmental samples from the outbreak area; thus, environmental surfaces are potential sources of virus transmission to humans and animals (5,6). LPMs have also been reported as sources of virus involved in human subtype H5N1 infection (7–9).
Birds sold at LPMs can originate from many regions of a country; thus, conducting surveillance for subtype H5N1 virus at these markets would probably be an effective way to monitor the circulation of virus within a country (7,9,10). It has been recommended that samples of drinking water shared by birds maintained within the same cage and samples of poultry feces be used to detect virus within LPMs (10,11). We performed this study to determine whether subtype H5N1 virus circulation in Cambodia could be better monitored by using environmental sampling in LPMs.