Serological and molecular epidemiological study on swine influenza in Zambia
Serological and molecular epidemiological study on swine influenza in Zambia
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赞比亚猪流感血清学和分子流行病学研究
DOI：
10.1111/tbed.14373
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发表时间：
2021
影响因子：
4.3
通讯作者：
Takada Ayato
中科院分区：
文献类型：
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作者：
Harima Hayato;Okuya Kosuke;Kajihara Masahiro;Ogawa Hirohito;Simulundu Edgar;Bwalya Eugene;Qiu Yongjin;Mori‐Kajihara Akina;Munyeme Musso;Sakoda Yoshihiro;Saito Takehiko;Hang'ombe Bernard M.;Sawa Hirofumi;Mweene Aaron S.;Takada Ayato
甲型流感病毒（IAV）在人类和动物中引起高度传染性的呼吸道疾病。2009年，一种猪源性大流行性H1N1 IAV，命名为A（H1N1）pdm 09病毒，在全球范围内传播，此后经常被引入猪群。由于具有大流行潜力的新型抗感染IAV可能在猪中出现，因此监测猪中的IAV不仅对养猪业而且对公共卫生都是必要的。然而，关于非洲猪感染IAV的流行病学资料仍然很少。在这项研究中，我们在2011-2018年期间从赞比亚的猪中收集了246份血清和605份鼻拭子样本。血清学分析显示，在2011年收集的血清中，分别有49%和32%的血清对A（H1N1）pdm 09病毒的血凝抑制（HI）和中和抗体呈阳性，而在随后的时期（2012-2018年）收集的血清中，两种血清学检测均呈阳性的不到5.3%。对A（H1N1）pdm 09病毒的阳性检出率和中和滴度均高于对猪H1N1和H1 N2 IAV的阳性检出率和中和滴度。另一方面，2011-2018年赞比亚猪群中猪H3 N2 IAV阳性率非常低（HI和中和试验分别为5.3%和0%）。从鼻拭子标本中分离到1株H3 N2和8株H1N1型IAV，分离率为1.5%。系统发育分析表明，分离的IAV与A（H1N1）pdm 09和季节性H3 N2毒株的亲缘关系较近。我们的研究结果表明，在赞比亚的研究期间发生了从人到猪的反向人畜共患病传播，并强调需要继续监测非洲猪群中IAV的传播状况。
Influenza A viruses (IAVs) cause highly contagious respiratory diseases in humans and animals. In 2009, a swine‐origin pandemic H1N1 IAV, designated A(H1N1)pdm09 virus, spread worldwide, and has since frequently been introduced into pig populations. Since novel reassortant IAVs with pandemic potential may emerge in pigs, surveillance for IAV in pigs is therefore necessary not only for the pig industry but also for public health. However, epidemiological information on IAV infection of pigs in Africa remains sparse. In this study, we collected 246 serum and 605 nasal swab samples from pigs in Zambia during the years 2011–2018. Serological analyses revealed that 49% and 32% of the sera collected in 2011 were positive for hemagglutination‐inhibition (HI) and neutralizing antibodies against A(H1N1)pdm09 virus, respectively, whereas less than 5.3% of sera collected during the following period (2012–2018) were positive in both serological tests. The positive rate and the neutralization titres to A(H1N1)pdm09 virus were higher than those to classical swine H1N1 and H1N2 IAVs. On the other hand, the positive rate for swine H3N2 IAV was very low in the pig population in Zambia in 2011–2018 (5.3% and 0% in HI and neutralization tests, respectively). From nasal swab samples, we isolated one H3N2 and eight H1N1 IAV strains with an isolation rate of 1.5%. Phylogenetic analyses of all eight gene segments revealed that the isolated IAVs were closely related to human IAV strains belonging to A(H1N1)pdm09 and seasonal H3N2 lineages. Our findings indicate that reverse zoonotic transmission from humans to pigs occurred during the study period in Zambia and highlight the need for continued surveillance to monitor the status of IAVs circulating in swine populations in Africa.