Centre for Global Health, Usher Institute, University of Edinburgh, Edinburgh, United Kingdom.
J Infect Dis. 2020 Oct 7;222(Suppl 7):S634-S639. doi: 10.1093/infdis/jiaa309.
Respiratory syncytial virus (RSV)-related acute lower respiratory infection is an important cause of death in infants and young children. However, little is known about the risk period for RSV-related deaths after presentation to health services with an RSV illness.
Using the Scottish national mortality database, we identified deaths from respiratory/circulatory causes (hereafter "respiratory/circulatory deaths") in young children aged <5 years during 2009-2016, whose medical history and records of laboratory-confirmed RSV infections were obtained by linking the mortality database to the national surveillance data set and the Scottish Morbidity Record. We used a self-controlled case series (SCCS) design to evaluate the relative incidence of deaths with respiratory/circulatory deaths in the first year after an RSV episode. We defined the risk interval as the first year after the RSV episode, and the control interval as the period before and after the risk interval until 5 years after birth. Age-adjusted incidence ratio and attributable fraction were generated using the R software package SCCS.
We included 162 respiratory/circulatory deaths, of which 36 occurred in children with a history of laboratory-confirmed RSV infection. We found that the mortality risk decreased with time after the RSV episode and that the risk was statistically significant for the month after RSV illness. More than 90% of respiratory/circulatory deaths occurring within 1 week after the RSV episode were attributable to RSV (attributable fraction, 93.9%; 95% confidence interval, 77.6%-98.4%), compared with about 80% of those occurring 1 week to 1 month after RSV illness (80.3%; 28.5%-94.6%).
We found an increased risk of death in the first month after an RSV illness episode leading to healthcare attendance. This provides a practical cutoff time window for community-based surveillance studies estimating RSV-related mortality risk. Further studies are warranted to assess the mortality risk beyond the first month after RSV illness episode.
呼吸道合胞病毒（RSV）相关的急性下呼吸道感染是婴儿和幼儿死亡的重要原因。然而，对于在出现 RSV 疾病后向卫生服务机构就诊的患者，RSV 相关死亡的风险期知之甚少。
我们利用苏格兰国家死亡率数据库，确定了 2009 年至 2016 年期间年龄<5 岁的因呼吸/循环原因（以下简称“呼吸/循环死亡”）而死亡的儿童，这些儿童的病史和经实验室确认的 RSV 感染记录是通过将死亡率数据库与国家监测数据集和苏格兰发病率记录相链接获得的。我们使用自身对照病例系列（SCCS）设计来评估 RSV 发作后第一年发生呼吸/循环死亡的相对发病率。我们将风险间隔定义为 RSV 发作后的第一年，将对照间隔定义为风险间隔之前和之后的时间段，直至出生后 5 年。使用 R 软件包 SCCS 生成年龄调整发病率比和归因分数。
我们纳入了 162 例呼吸/循环死亡病例，其中 36 例发生在有实验室确认 RSV 感染史的儿童中。我们发现，死亡率随着 RSV 发作后时间的推移而降低，并且在 RSV 疾病后一个月的风险具有统计学意义。在 RSV 发作后 1 周内发生的超过 90%的呼吸/循环死亡归因于 RSV（归因分数，93.9%；95%置信区间，77.6%-98.4%），而在 RSV 疾病后 1 周到 1 个月期间发生的则为 80%左右（80.3%；28.5%-94.6%）。
我们发现，在因 RSV 疾病就诊后的第一个月内，死亡风险增加。这为基于社区的监测研究提供了一个估计 RSV 相关死亡率风险的实用截止时间窗口。需要进一步研究来评估 RSV 疾病发作后第一个月后的死亡率风险。
