Background Respiratory syncytial virus (RSV) is a leading cause of acute respiratory illnesses (ARI) in children. RSV can be broadly categorized into two major subtypes (A and B). RSV subtypes have been known to co-circulate with variability in different regions of the world. Clinical associations with viral subtype have been studied among children with conflicting findings such that no conclusive relationships between RSV subtype and severity have been established. Methods During 2016–2020, children <5 years old were enrolled in prospective surveillance in the emergency department (ED) or inpatient (IP) settings from seven U.S. pediatric medical centers. Surveillance data collection included parent/guardian interviews, chart reviews, and collection of mid-turbinate nasal +/- throat swabs for RSV (RSV-A, RSV-B, and Untyped) by reverse transcription polymerase chain reaction (RT-PCR). Results Among 6398 RSV-positive children <5 years old, 3424 (54%) had subtype RSV-A infections, 2602 (41%) had subtype RSV-B infections, and 272 (5%) were not typed, inconclusive, or mixed infections. In both adjusted and unadjusted analyses, RSV-A-positive children were more likely to be hospitalized, as well as when restricted to <1 year. By season, RSV-A and RSV-B co-circulated in varying levels, with one subtype dominating proportionally. Conclusion Findings indicate that RSV-A and RSV-B may only be marginally clinically distinguishable but both subtypes are associated with medically attended illness in children <5 years old. Furthermore, circulation of RSV subtypes varies substantially each year, seasonally and geographically. With introduction of new RSV prevention products, this highlights the importance of continued monitoring of RSV-A and RSV-B subtypes.

中文翻译：

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五岁以下儿童呼吸道合胞病毒病按亚型的季节性、临床特征和结果，新疫苗监测网络，美国，2016-2020 年

背景 呼吸道合胞病毒（RSV）是儿童急性呼吸道疾病（ARI）的主要原因。RSV 可大致分为两个主要亚型（A 和 B）。众所周知，RSV 亚型在世界不同地区共同传播且存在变异。在儿童中对病毒亚型的临床关联进行了研究，结果相互矛盾，因此尚未确定 RSV 亚型和严重程度之间确实的关系。方法 2016 年至 2020 年期间，来自七个美国儿科医疗中心的急诊科 (ED) 或住院部 (IP) 机构对 5 岁以下儿童进行了前瞻性监测。监测数据收集包括家长/监护人访谈、图表审查以及通过逆转录聚合酶链反应 (RT-PCR) 收集中鼻甲鼻 +/- 喉咙拭子的 RSV（RSV-A、RSV-B 和未分型）。结果 6398 名小于 5 岁的 RSV 阳性儿童中，3424 名（54%）有 RSV-A 亚型感染，2602 名（41%）有 RSV-B 亚型感染，272 名（5%）未分型、不确定或未分型。混合感染。在调整和未调整的分析中，RSV-A 阳性儿童更有可能住院，并且当限制在<1岁时也是如此。按季节划分，RSV-A 和 RSV-B 以不同程度共同传播，其中一种亚型按比例占主导地位。结论 研究结果表明，RSV-A 和 RSV-B 在临床上可能仅有轻微的区别，但这两种亚型都与 5 岁以下儿童的医疗疾病相关。此外，RSV 亚型的传播每年、季节和地理上都有很大差异。随着新的 RSV 预防产品的推出，凸显了持续监测 RSV-A 和 RSV-B 亚型的重要性。