生鳥市場における高病原性鳥インフルエンザに対する衛生向上のためのリスク分析

本财政年度，我们重点进行了以下研究，以评估目前对活禽市场的干预措施，以尽量减少禽流感病毒向家禽和人类传播的风险。将基础设施改善的lbm的特点与越南常规操作的lbm进行了比较。该研究表明，在有或没有干预的lbm监测期间，可分离出各种亚型的aiv。此外，在其中一个干预lbm中，从表面健康的鸭、番鸭和环境样本中分离到了H5N6高致病性禽流感病毒（HPAIVs）。干预后lbm与非干预后lbm的aiv患病率相似。这些结果表明，目前在越南中部地区lbm实施的干预措施不足以控制禽流感。为了确定在这两种类型的lbm中导致AIV传播的因素，研究重点是对禽类、禽类卖家和市场层面的特征进行量化，这些特征使单个禽类在销售时更有可能是AIV分离阳性。结果表明，在调整了市场和个体卖家水平的聚类后，问卷中征求的解释变量都没有与AIV阳性显著相关。艾滋病病毒阳性风险变化的一个相对较小的组成部分是在个别市场水平。这表明禽流感控制工作的重点应放在卖方而不是市场一级。

This fiscal year, we focused on the following research to evaluate the current interventions on live bird market (LBM) in order to minimize the risk of avian influenza virus (AIV) transmission to poultry and humans.The characteristics of LBMs with improved infrastructure were compared with those operating in a routine manner in Vietnam. The study showed that various subtypes of AIVs were isolated during surveillance of LBMs with or without intervention. In addition, H5N6 highly pathogenic avian influenza viruses (HPAIVs) were isolated from apparently healthy ducks, Muscovy ducks and environmental samples in one of the intervention LBMs. And the prevalence of AIVs in intervention LBMs was similar to that in non-intervention LBMs. These results suggest that the interventions currently applied in LBMs in center part of Vietnam are insufficient to control avian influenza.To identify the factors contributing to AIVs circulation in both types of LBMs, this focused on quantification of bird-, poultry seller- and market-level characteristics that rendered individual birds more likely to be AIV isolation positive at the time of sale. The results demonstrate that after adjusting for clustering at the market- and individual seller-level none of the explanatory variables solicited in the questionnaire were significantly associated with AIV positivity. A relatively small component of the variation in AIV positivity risk was at the individual market-level. It indicates that the emphasis of avian influenza control efforts should be at the seller-level rather than market-level.