Bird Flu Outbreaks Linked to Live Bird Traders, Markets

VIET NAM - The H5N1 avian influenza virus has been spread by live poultry traders at live bird markets, according to this international study but this information can be used to help improve biosecurity and reduce future outbreaks.

2 March 2010

3 minute read

Ricardo Soares Magalhaes at the Royal Veterinary College in the UK, and co-authors at the University of Queensland, Department of Animal Health in Hanoi and the FAO collaborated on a study of the associations between live poultry trade and outbreaks of H5N1 highly pathogenic avian influenza (HPAI). Their paper is published in BMC Veterinary Research.

The structure of contact between individuals plays an important role in the incursion and spread of contagious diseases in both human and animal populations. In the case of avian influenza, the movement of live birds is a well known risk factor for the geographic dissemination of the virus among poultry flocks. Live bird markets (LBMs) contribute to the epidemiology of avian influenza due to their demographic characteristics and the presence of HPAI H5N1 virus lineages. The relationship between poultry producers and live poultry traders (LPTs) that operate in LBMs has not been adequately documented in HPAI H5N1-affected SE Asian countries. The aims of this study were to document and study the flow of live poultry in a poultry trade network in northern Vietnam, and explore its potential role in the risk for HPAI H5N1 during 2003 to 2006.

Results

The results of the study indicate that LPTs trading for less than a year and operating at retail markets are more likely to source poultry from flocks located in communes with a past history of HPAI H5N1 outbreaks during 2003 to 2006 than LPTs trading longer than a year and operating at wholesale markets. The results of the network analysis indicate that LPTs tend to link communes of similar infection status.

Conclusions

The researchers say that their study provides evidence, which can be used for informing policies aimed at encouraging more biosecure practices of LPTs operating at authorised LBMs.

The results suggest that LPTs play a role in HPAI H5N1 transmission and may contribute to perpetuating HPAI H5N1 virus circulation amongst certain groups of communes. The impact of current disease prevention and control interventions could be enhanced by disseminating information about outbreak risk and the implementation of a formal data recording scheme at LBMs for all incoming and outgoing LPTs.

Reference

Magalhaes R.J.S., A. Ortiz-Pelaez, K.L.L. Thi, Q.H. Dinh, J. Otte and D.U. Pfeiffer. 2010. Associations between attributes of live poultry trade and HPAI H5N1 outbreaks: a descriptive and network analysis study in northern Vietnam. BMC Veterinary Research, 6:10. doi:10.1186/1746-6148-6-10.