Department of Biomedical Sciences and Human Oncology-Hygiene Section, University of Bari, Piazza G. Cesare 11, 70124 Bari, Italy.
Department of Biosciences, Biotechnology and Biopharmaceutics, University of Bari, Via Orabona 4, 70124 Bari, Italy.
Biomed Res Int. 2019 Aug 20;2019:4643260. doi: 10.1155/2019/4643260. eCollection 2019.
Yearly influenza epidemics have considerable effects on public health worldwide. The 2017-2018 influenza season in Italy was of greater severity than previous seasons. The aim of this study was to describe the 2017-2018 influenza season in Southern Italy and the molecular characteristics of the circulating viral strains.
The incidence of influenza-like illness (ILI) was analysed. Nasopharyngeal swabs collected from patients with ILI from week 46/2017 to week 17/2018 were tested to identify influenza A viruses (IAV) and influenza B viruses (IBV). Sequencing and phylogenetic analysis of haemagglutinin genes were also performed on 73 positive samples (35 IBV, 36 IAV H1, and 2 IAV H3 strains).
During the 2017-2018 season, the peak incidence was 14.32 cases per 1,000 inhabitants. IBV strains were identified in 71.0% of cases. The 35 characterised IBV strains belonged to Yamagata lineage clade 3, the 36 A/H1N1pdm09 strains clustered with the genetic subgroup 6B.1, and the 2 A/H3N2 strains clustered with the genetic subgroup 3C.2a. Intensive-care unit (ICU) admission was required in 50 cases of acute respiratory distress syndrome (ARDS). Among the >64-year age group, 18 out of 26 ICU-ARDS cases (69.2%) were caused by IBV, and 14 of these (77.8%) were B/Yamagata lineage.
The 2017-2018 influenza season was one of the most severe in a decade in Southern Italy. IBV mismatch between the trivalent vaccine and the circulating strains occurred. The high number of ICU-ARDS cases caused by B/Yamagata strains in the >64-year age group suggests that further data on the effectiveness of the available influenza vaccines are needed to determine the best way to protect the elderly against both IBV lineages.
每年的流感疫情都会对全球公共卫生造成重大影响。意大利 2017-2018 年流感季的严重程度超过了以往各季。本研究旨在描述 2017-2018 年意大利南部流感季的情况以及流行病毒株的分子特征。
分析流感样疾病（ILI）的发病率。从 2017 年第 46 周至 2018 年第 17 周ILI 患者的鼻咽拭子中检测出甲型流感病毒（IAV）和乙型流感病毒（IBV）。对 73 份阳性样本（35 份 IBV、36 份 IAV H1 和 2 份 IAV H3 株）的血凝素基因进行测序和系统发育分析。
在 2017-2018 年流行季，发病率最高达每 1000 居民 14.32 例。71.0%的病例中鉴定出 IBV 株。35 株鉴定的 IBV 株属于 Yamagata 谱系 3 分支，36 株 A/H1N1pdm09 株聚类于遗传亚群 6B.1，2 株 A/H3N2 株聚类于遗传亚群 3C.2a。50 例急性呼吸窘迫综合征（ARDS）需要入住重症监护病房（ICU）。64 岁以上人群中，26 例 ICU-ARDS 病例中有 18 例（69.2%）由 IBV 引起，其中 14 例（77.8%）为 B/Yamagata 谱系。
2017-2018 年流感季是意大利南部 10 年来最严重的一次流感季。三价疫苗与流行株之间发生了 IBV 错配。64 岁以上人群中由 B/Yamagata 株引起的 ICU-ARDS 病例较多，这表明需要进一步评估现有流感疫苗的有效性数据，以确定保护老年人免受两种 IBV 谱系感染的最佳方法。
