Kaiser Permanente Washington, Renton, Washington, United States of America.
Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America.
PLoS One. 2020 Oct 15;15(10):e0240783. doi: 10.1371/journal.pone.0240783. eCollection 2020.
Understanding and monitoring the demographics of SARS-CoV-2 infection can inform strategies for prevention. Surveillance monitoring has suggested that the age distribution of people infected with SARS-CoV-2 has changed since the pandemic began, but no formal analysis has been performed.
Retrospective review of SARS-CoV-2 molecular testing results from a national reference laboratory was performed. Result distributions by age and positivity were compared between early period (March-April 2020) and late periods (June-July 2020) of the COVID-19 pandemic. Additionally, a sub-analysis compared changing age distributions between inpatients and outpatients.
There were 277,601 test results of which 19320 (7.0%) were positive. The median age of infected people declined over time (p < 0.0005). In March-April, the median age of positive people was 40.8 years (Interquartile range (IQR): 29.0-54.1). In June-July, the median age of positive people was 35.8 years (IQR: 24.0-50.2). The positivity rate of patients under 50 increased from 6.0 to 10.6 percent and the positivity rate for those over 50 decreased from 6.3 to 5.0 percent between the early and late periods. The trend was only observed for outpatient populations.
We confirm that there is a trend toward decreasing age among persons with laboratory-confirmed SARS-CoV-2 infection, but that these trends seem to be specific to the outpatient population. Overall, this suggests that observed age-related trends are driven by changes in testing patterns rather than true changes in the epidemiology of SARS-CoV-2 infection. This calls for caution in interpretation of routine surveillance data until testing patterns stabilize.
了解和监测 SARS-CoV-2 感染的人口统计学特征可以为预防策略提供信息。监测监测表明，自大流行开始以来，感染 SARS-CoV-2 的人群的年龄分布发生了变化，但尚未进行正式分析。
对国家参考实验室的 SARS-CoV-2 分子检测结果进行回顾性审查。比较 COVID-19 大流行早期（2020 年 3 月至 4 月）和晚期（2020 年 6 月至 7 月）的年龄和阳性率的结果分布。此外，还进行了一项亚分析，比较了住院患者和门诊患者之间年龄分布的变化。
共检测了 277601 份检测结果，其中阳性结果 19320 份（7.0%）。感染人群的中位年龄随时间推移而降低（p<0.0005）。在 3 月至 4 月期间，阳性人群的中位年龄为 40.8 岁（四分位距（IQR）：29.0-54.1）。在 6 月至 7 月期间，阳性人群的中位年龄为 35.8 岁（IQR：24.0-50.2）。50 岁以下患者的阳性率从 6.0%上升到 10.6%，50 岁以上患者的阳性率从 6.3%下降到 5.0%。这种趋势仅在门诊人群中观察到。
我们证实，实验室确诊的 SARS-CoV-2 感染人群的年龄呈下降趋势，但这些趋势似乎仅适用于门诊人群。总体而言，这表明观察到的与年龄相关的趋势是由检测模式的变化而非 SARS-CoV-2 感染的流行病学的真正变化所驱动的。在检测模式稳定之前，应谨慎解释常规监测数据。
