Assessing alternative low pathogenic avian influenza virus surveillance strategies in a live bird market

Surveillance, comprised of sampling and testing, of low pathogenic avian influenza virus (LPAIV) in a live bird market (LBM) may enable the detection of the virus, reducing its spread within the market to humans and birds and to other markets within the LBM system. In addition, detection of infected birds would also reduce the probability of reassortment and possible change from a LPAIV to a highly pathogenic avian influenza virus, which would have a devastating impact on the economy, trade, and society. In this paper we present results from a computer simulation model based on previously collected survey and experimental transmission data. Once we validated the model with experimental transmission data, we applied it to address some of the questions that need to be answered in order to create an efficient surveillance system in an LBM. We have identified effective sampling times, patterns, and sizes that would enhance the probability of an early detection of LPAIV if present and minimize the associated labor and cost. The model may be modified to evaluate different sized and structured LBMs. It also provides the basis to evaluate an entire LBM system for the United States or other countries.