INTRODUCTION Respiratory syncytial virus (RSV) is associated with substantial morbidity and mortality since it is a predominant viral agent causing respiratory tract infections in infants, young children and the elderly. Considering the availability of the RSV vaccines in the coming years, molecular understanding in RSV is necessary. OBJECTIVE The objective of the present study was to describe RSV epidemiology and genotype variability in Portugal during the 2014/15-2017/18 period. MATERIAL AND METHODS Epidemiological data and RSV-positive samples from patients with a respiratory infection were collected through the non-sentinel and sentinel influenza surveillance system (ISS). RSV detection, subtyping in A and B, and sequencing of the second hypervariable region (HVR2) of G gene were performed by molecular methods. Phylogenetic trees were generated using the Neighbor-Joining method and p-distance model on MEGA 7.0. RESULTS RSV prevalence varied between the sentinel (2.5%, 97/3891) and the non-sentinel ISS (20.7%, 3138/16779), being higher (P < 0.0001) among children aged <5 years. Bronchiolitis (62.9%, 183/291) and influenza-like illness (24.6%, 14/57) were associated (P < 0.0001) with RSV laboratory confirmation among children aged <6 months and adults ≥65 years, respectively. The HVR2 was sequenced for 562 samples. RSV-A (46.4%, 261/562) and RSV-B (53.6%, 301/562) strains clustered mainly to ON1 (89.2%, 233/261) and BA9 (92%, 277/301) genotypes, respectively, although NA1 and BA10 were also present until 2015/2016. CONCLUSION The sequence and phylogenetic analysis reflected the relatively high diversity of Portuguese RSV strains. BA9 and ON1 genotypes, which have been circulating in Portugal since 2010/2011 and 2011/2012 respectively, predominated during the whole study period.

中文翻译：

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2014-2018年葡萄牙呼吸道合胞病毒的流行病学和遗传变异性。

引言呼吸道合胞病毒（RSV）与大量发病和死亡相关，因为它是导致婴儿，幼儿和老年人呼吸道感染的主要病毒因子。考虑到未来几年中RSV疫苗的可用性，对RSV的分子了解是必要的。目的本研究的目的是描述2014 / 15-2017 / 18期间葡萄牙的RSV流行病学和基因型变异性。材料和方法通过非前哨和前哨流感监测系统（ISS）收集了呼吸道感染患者的流行病学数据和RSV阳性样本。RSV检测，A和B中的亚型分型以及G基因的第二个高变区（HVR2）的测序是通过分子方法进行的。系统进化树是使用MEGA 7.0上的Neighbor-Joining方法和p距离模型生成的。结果前哨（2.5％，97/3891）和非前哨ISS（20.7％，3138/16779）之间的RSV患病率不同，在5岁以下儿童中较高（P <0.0001）。年龄<6个月的儿童和≥65岁的成年人中，细支气管炎（62.9％，183/291）和类流感样疾病（24.6％，14/57）与RSV实验室确认有关（P <0.0001）。对HVR2进行了562个样品的测序。RSV-A（46.4％，261/562）和RSV-B（53.6％，301/562）菌株分别主要集中于ON1（89.2％，233/261）和BA9（92％，277/301）基因型。尽管NA1和BA10也一直存在到2015/2016年。结论序列和系统发育分析反映了葡萄牙RSV毒株相对较高的多样性。