Adeola Oluwagbenga A, Olugasa Babasola O, Emikpe Benjamin O, Folitse Raphael D
Centre for Control and Prevention of Zoonoses (CCPZ), University of Ibadan, Ibadan, Nigeria.
Department of Medical Microbiology and Parasitology, College of Medicine and Health Sciences, Bingham University, Karu, Abuja, Nigeria.
Zoonoses Public Health. 2019 Mar;66(2):232-247. doi: 10.1111/zph.12559. Epub 2019 Jan 24.
Influenza viruses are frequently transmitted between pigs and their handlers, and among pig handlers. However, reports on socio-environmental variables as potential risk factors associated with transmission of influenza in West African swine production facilities are very scarce. Syndromic survey for influenza was therefore conducted in Ibadan, Nigeria, and Kumasi, Ghana, in order to identify and elucidate selected socio-environmental variables that may contribute to the occurrence and distribution of influenza-like illness (ILI) among swine industry workers. In addition, molecular analyses were conducted to elucidate the nature of influenza viruses circulating at the human-swine interface in these cities and better understand the dynamics of their transmission. Influenza viruses were detected by type-specific and subtype-specific RT-PCR. Sequencing and phylogenetic analyses were carried out. Socio-environmental variables were tested by both univariable and multivariable regression methods for significance at p < 0.05. Three risk factors for ILI were identified in each city. These included "frequency of visit of pig handler to pig pen or lairage" (Ibadan: risk ratio [RR] = 1.54, 95% confidence interval [CI] = 1.36-1.79, p = 0.02; Kumasi: RR = 1.28, 95% CI = 1.11-1.71, p = 0.01) and "pig handler's awareness about biosecurity measures" (Ibadan: RR = 7.09, 95% CI = 2.36-21.32, p < 0.001; Kumasi: RR = 4.84, 95% CI = 1.98-11.80, p < 0.001). Influenza A(H1N1)pdm09 viruses, with M genes closely related to those which circulated among pigs in the two cities during the same period, were detected among Nigerian and Ghanaian pig industry workers. These findings suggest the possibility of bidirectional transmission of influenza at the human-swine interface in these cities and underscore the need for more extensive molecular studies. Risk factors identified may assist in the control of human-to-human and human-to-swine transmission of influenza in the West African swine industry.
流感病毒经常在猪及其饲养人员之间传播，也在饲养人员之间传播。然而，关于社会环境变量作为西非养猪生产设施中流感传播潜在风险因素的报告非常稀少。因此，在尼日利亚伊巴丹和加纳库马西进行了流感症状调查，以确定和阐明可能导致养猪业工人中流感样疾病（ILI）发生和分布的特定社会环境变量。此外，还进行了分子分析，以阐明这些城市人猪界面处流行的流感病毒的性质，并更好地了解其传播动态。通过型特异性和亚型特异性逆转录聚合酶链反应（RT-PCR）检测流感病毒。进行了测序和系统发育分析。采用单变量和多变量回归方法对社会环境变量进行检验，显著性水平为p < 0.05。在每个城市都确定了ILI的三个风险因素。这些因素包括“养猪人员进入猪圈或牲畜栏的频率”（伊巴丹：风险比[RR]=1.54，95%置信区间[CI]=1.36 - 1.79，p = 0.02；库马西：RR = 1.28，95% CI = 1.11 - 1.71，p = 0.01）和“养猪人员对生物安全措施的认识”（伊巴丹：RR = 7.09，95% CI = 2.36 - 21.32，p < 0.001；库马西：RR = 4.84，95% CI = 1.98 - 11.80，p < 0.001）。在尼日利亚和加纳的养猪业工人中检测到甲型（H1N1）pdm09流感病毒，其M基因与同期在这两个城市猪群中流行的病毒密切相关。这些发现表明这些城市人猪界面处存在流感双向传播的可能性，并强调需要进行更广泛的分子研究。确定的风险因素可能有助于控制西非养猪业中流感的人际传播和人猪传播。
