Department of Occupational and Environmental Health, Xiangya School of Public Health, Central South University, Changsha, 410078, China.
Changsha Center for Disease Control and Prevention, Changsha, 410004, China.
Food Environ Virol. 2022 Mar;14(1):30-39. doi: 10.1007/s12560-021-09506-9. Epub 2022 Jan 7.
In routine surveillance for avian influenza viruses (AIVs) in the environments of live poultry markets (LPMs), certain samples were positive for AIVs type A while negative for subtypes (e.g., H5, H7, and H9). However, little attention has been paid to these unsubtyped AIVs samples. To reveal the dynamic distribution and molecular characteristics of AIVs, especially the unsubtyped AIVs, we reported and analyzed 1969 samples collected from the water environments of LPMs in Changsha, China, from January 2014 to November 2018. Our results revealed that 1504 (76.38%) samples were positive for AIV type A. Of these samples, the predominant hemagglutinin (HA) subtype was H9, followed by H5 and H7 (P < 0.05). The positive rate of H5 subtype in water environmental samples exhibited seasonality, which reached a peak in each winter-spring season from January 2014 to March 2017. The positive rates of AIVs (including type A, subtype H9, and mixed subtype H5/H7/H9) in non-central-city regions were higher than that in the central-city regions (P < 0.05). Notably, 161 unsubtyped AIVs samples were detected during the routine surveillance. However, subtyping with the commercial kit further identified eight different HA and seven different neuraminidase subtypes. Analyses unraveled that further subtyped AIVs H1, H6, and H11 had only one basic amino acid (R or K) at the cleavage site and residues Q and G at the receptor-binding associated sites. Overall, in addition to H5, H7, and H9 subtypes, we should also pay attention to unsubtyped AIVs samples during the routine surveillance for AIVs in the environments of LPMs.
在对活禽市场（LPM）环境中的禽流感病毒（AIVs）进行常规监测时，某些样本对 AIV 呈阳性，但对亚型（如 H5、H7 和 H9）呈阴性。然而，这些未分型的 AIV 样本并没有引起太多关注。为了揭示 AIV 的动态分布和分子特征，特别是未分型的 AIVs，我们报告并分析了 2014 年 1 月至 2018 年 11 月期间从中国长沙 LPM 水环境中采集的 1969 个样本。结果表明，1504 个（76.38%）样本对 AIV 呈阳性。在这些样本中，主要的血凝素（HA）亚型是 H9，其次是 H5 和 H7（P<0.05）。水环境样本中 H5 亚型的阳性率具有季节性，从 2014 年 1 月至 2017 年 3 月的每个冬春季节达到高峰。非市中心地区 AIVs（包括 A 型、H9 亚型和混合亚型 H5/H7/H9）的阳性率高于市中心地区（P<0.05）。值得注意的是，在常规监测中检测到 161 个未分型的 AIV 样本。然而，使用商业试剂盒进一步鉴定出了 8 种不同的 HA 和 7 种不同的神经氨酸酶亚型。分析表明，进一步分型的 AIVs H1、H6 和 H11 在裂解位点只有一个碱性氨基酸（R 或 K）和受体结合相关位点的 Q 和 G 残基。总的来说，除了 H5、H7 和 H9 亚型外，我们还应该在对 LPM 环境中的 AIV 进行常规监测时注意未分型的 AIV 样本。
