Investigating poultry trade patterns to guide avian influenza surveillance and control: a case study in Vietnam

Abstract

Live bird markets are often the focus of surveillance activities monitoring avian influenza viruses (AIV) circulating in poultry. However, in order to ensure a high sensitivity of virus detection and effectiveness of management actions, poultry management practices features influencing AIV dynamics need to be accounted for in the design of surveillance programmes. In order to address this knowledge gap, a cross-sectional survey was conducted through interviews with 791 traders in 18 Vietnamese live bird markets. Markets greatly differed according to the sources from which poultry was obtained, and their connections to other markets through the movements of their traders. These features, which could be informed based on indicators that are easy to measure, suggest that markets could be used as sentinels for monitoring virus strains circulating in specific segments of the poultry production sector. AIV spread within markets was modelled. Due to the high turn-over of poultry, viral amplification was likely to be minimal in most of the largest markets. However, due to the large number of birds being introduced each day, and challenges related to cleaning and disinfection, environmental accumulation of viruses at markets may take place, posing a threat to the poultry production sector and to public health.

Assessing the role of live poultry trade in community-structured transmission of avian influenza in China

“…S6) were constructed from statistics of poultry egg production and populations of domestic poultry, using a classic gravity model. This model is supported by crosssectional surveys of poultry transportation in Cambodia (36) and Vietnam (37). In summary, the flux of live poultry or poultry egg transport (G ij ) between provinces i and j separated by geographic distance d ij takes the form G ij = N i N j d ij −1 , where N i is the number of live poultry (unit: 10,000 poultry) or the amount of poultry egg production (unit: ton) in source province i (averaged across years) and N j is human population size (unit: 10,000 people) in destination province j (averaged across years).…”

A systematic review of MERS-CoV seroprevalence and RNA prevalence in dromedary camels: Implications for animal vaccination

“…Quantitative data describing the movement and trading patterns of dromedary populations will be essential for informing models and considering where potential vaccination should take place. A role for markets as drivers of disease dissemination is characteristic of other zoonotic diseases such as avian influenza (Gilbert et al, 2014;Fournié et al, 2016).…”

Poultry trading behaviours in Vietnamese live bird markets as risk factors for avian influenza infection in chickens

“…When considering the potential impact on AIV dissemination that these traders can have, it is important to take note of the position that vendors have in the poultry trade network. Vendors who have strong connections to a network of contacts operating in and around LBMs would be expected to have a more pronounced role in disseminating AIVs, whereas vendors holding a loose link to a network of contacts may have a reduced impact on AIV dissemination (Fournié et al, ). Thus, middlemen are mobile, highly connected poultry traders that travel between farms and LBMs to purchase and sell birds, mixing poultry from many different sources.…”

“…Poultry production and trade in LMICs are heterogeneous, with different species being brought together from various size farming systems, often without robust biosecurity (Fournié et al, ; Webster, ). Live bird markets (LBMs) are a traditional aspect of these systems that facilitate the storage and sale of live poultry including chickens, ducks, quail and pigeons.…”