Meseko C A, Heidari A, Odaibo G N, Olaleye D O
Regional Center for Animal Influenza, National Veterinary Research Institute, Vom, Nigeria.
Formerly, Istituto Zooprofilattico Sperimentale delle Venezie, (IZSVe), FAO Reference Center for Animal Influenza and Newcastle Disease virus, OIE Reference Laboratory for Avian Influenza and Newcastle Disease virus, OIE Collaborating Laboratory for Diseases at the Human-Animal Interface, Padova, Italy.
Infect Ecol Epidemiol. 2019 Dec 2;9(1):1696632. doi: 10.1080/20008686.2019.1696632. eCollection 2019.
Prevailing agro-ecological conditions and intermingling of human and animals in intensive farms in urban and peri-urban areas in Africa favour cross species transmission of pathogens at the human-animal interface. However, molecular epidemiology studies of zoonotic swine influenza viruses in this region are limited. In this study, isolates of pandemic influenza virus (H1N1pdm09) obtained from pigs in Nigeria were fully sequenced. BLAST of swine influenza virus genes from Nigeria was carried out in GenBank and gene alignment was done using MEGA version 7. Maximum likelihood method (PhyML program) was used to determine gene evolutionary relationships with other viruses and phylogenetic trees were constructed to infer genomic clusters and relationship. Swine influenza viruses isolated and sequenced in this study were monophyletic and 99% congenetic with human isolates from Nigeria, Cameroon, Ghana and USA suggesting reverse zoonotic transmission from humans to pigs in intensive husbandry. A Q240R and S31N substitution among others were detected in the haemagglutinin and matrix genes, respectively, indicating potentials for mutations during interspecies co-mingling and transmission. The A/H1N1pdm09 viruses circulating in pigs that are also exposed to avian influenza in the same epidemiological zones could engender emergence of novel viruses with zoonotic or pandemic potential requiring enhanced surveillance and monitoring.
非洲城市和城郊地区集约化养殖场中普遍存在的农业生态条件以及人畜混居的情况，有利于病原体在人畜界面发生跨物种传播。然而，该地区人畜共患猪流感病毒的分子流行病学研究有限。在本研究中，对从尼日利亚猪身上分离得到的大流行性流感病毒（H1N1pdm09）毒株进行了全基因组测序。在GenBank中对来自尼日利亚的猪流感病毒基因进行了BLAST比对，并使用MEGA 7版本进行基因比对。采用最大似然法（PhyML程序）确定与其他病毒的基因进化关系，并构建系统发育树以推断基因组聚类和关系。本研究中分离和测序的猪流感病毒是单系的，与来自尼日利亚、喀麦隆、加纳和美国的人类分离株有99%的同源性，这表明在集约化养殖中存在从人到猪的反向人畜共患传播。分别在血凝素和基质基因中检测到Q240R和S31N等替换，表明在种间混合和传播过程中存在突变的可能性。在同一流行区同时接触禽流感的猪中传播的A/H1N1pdm09病毒可能会产生具有人畜共患或大流行潜力的新型病毒，这需要加强监测和监控。
