Multiannual patterns of influenza A transmission in Chinese live bird market systems

Abstract

Please cite this paper as: Pepin et al. (2012) Multiannual patterns of influenza A transmission in Chinese live bird market systems. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750‐2659.2012.00354.x. Background Avian influenza viruses (AIV) cause huge economic losses in poultry industries and pose a substantial threat to human health. However, predicting AIV epizootics and emergence in humans is confounded by insufficient empirical data on the ecology and dynamics of AIV in poultry systems. To address this gap, we quantified incidence patterns for 13 hemagglutinin subtypes of AIV using 6 years of surveillance data that were collected from ten different species of poultry and three different types of poultry holdings (contexts) – retail, wholesale, or farms. Methods We collected 42 646 samples in Shantou, China between 2000 and 2006. We screened samples for hemagglutinin subtypes 1–13 of AIV and Avian Paramyxovirus‐type‐1 (APMV‐1) using monospecific antisera in hemagglutination inhibition tests. We analyzed the data to determine seasonality patterns, subtype–host, and subtype–subtype interactions as well as subtype bias in incidence in different contexts. Results H3, H6, H9, and APMV‐1 were the most prevalent. No significant seasonality was found when all subtypes were considered together. For most AIV subtypes and APMV‐1, there was subtype specificity for host, context, and coinfection partner. H5 showed the most generalized host usage pattern, followed by H9 and H6. Conclusion Subtype‐specific patterns because of host, context, and other subtypes suggest that risk assessments that exclude these details are likely inaccurate. Surveillance should include longitudinal sampling of multiple host species in multiple contexts. Quantitative models of control strategies must consider multiple subtypes, hosts, and source contexts to assess the effectiveness of interventions.

The role of live poultry movement and live bird market biosecurity in the epidemiology of influenza A (H7N9): A cross-sectional observational study in four eastern China provinces

“…18 Other studies have shown that the prevalence of particular avian influenza viruses in retail LBMs is twice as high as the prevalence in wholesale LBMs. 26,27 However, our results have shown that in the case of H7N9, the market level infection was significantly associated with wholesale and mixed LBMs compared to retail markets suggesting that particular biosecurity practices within wholesale and mixed LBMs may be a good indicator for H7N9 presence. Initial reports had proposed that visits to retail markets during the first wave of H7N9 had posed humans at increased risk of H7N9 infection by facilitating the transmission of avian influenza viruses due to lower biosecurity levels and increased access by consumers.…”

The emergence and diversification of panzootic H5N1 influenza viruses

“…Surveillance data has demonstrated that H5N1 viruses are perpetuated primarily in domestic ducks in this region (Li et al, 2004; Smith et al, 2006a). Approximately 11% of influenza A positive samples collected from poultry in Southern China were positive for multiple influenza subtypes, indicating co-infections, with the majority of these samples coming from ducks in farms and markets (Pepin et al, 2012). Furthermore, it has been demonstrated that domestic ducks experience asymptomatic infection to H5N1 viruses and shed virus over extended periods, which was also observed in our surveillance (Sturm-Ramirez et al, 2005).…”

“…Additionally, current knowledge cannot explain why only one-way transmission of HPAI H5N1 viruses has occurred, from Asia to Europe and then to Africa, with no apparent reverse West-East transmission. It is likely that many factors, such as poultry movement, or species specificity of different subtype influenza viruses are involved (Munster et al, 2007; Pepin et al, 2012). …”

Complete Genome Sequence of an H10N8 Avian Influenza Virus Isolated from a Live Bird Market in Southern China

“…In recent years, several subtypes of avian influenza viruses (AIVs) have been circulating and evolving in southern China, including H3, H5, H6, and H9 (1, 2, 4, 5, 7). In such an environment, live bird markets (LBM) in southern China are an important source of AIV dissemination, where diverse subtypes of AIVs have been isolated (5). Thus, continuous epidemiological surveillance in LBM is very important to investigate the evolution of known and unknown AIVs.…”