Objectives

To estimate the burden and severity of suspected reinfection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Methods

A retrospective cohort of members of Kaiser Permanente Southern California with PCR-positive SARS-CoV-2 infection between 1st March 2020 and 31st October 2020 was followed through electronic health records for subsequent positive SARS-CoV-2 tests (suspected reinfection) ≥90 days after initial infection, through 31st January 2021. Incidence of suspected reinfection was estimated using the Kaplan–Meier method. Cox proportional hazards models estimated the association of suspected reinfection with demographic and clinical characteristics, hospitalization, and date of initial infection.

Results

The cohort of 75 149 was predominantly Hispanic (49 648/75 149, 66.1%) and included slightly more females than males (39 736, 52.9%), with few immunocompromised patients (953, 1.3%); 315 suspected reinfections were identified, with a cumulative incidence at 270 days of 0.8% (95% confidence interval (CI) 0.7–1.0%). Hospitalization was more common at suspected reinfection (36/315, 11.4%) than initial infection (4094/75 149, 5.4%). Suspected reinfection rates were higher in females (1.0%, CI 0.8–1.2% versus 0.7%, CI 0.5–0.9%, p 0.002) and immunocompromised patients (2.1%, CI 1.0–4.2% versus 0.8%, CI 0.7–1.0%, p 0.004), and lower in children than adults (0.2%, CI 0.1–0.4% versus 0.9%, CI 0.7–1.0%, p 0.023). Patients hospitalized at initial infection were more likely to have suspected reinfection (1.2%, CI 0.6–1.7% versus 0.8%, CI 0.7–1.0%, p 0.030), as were those with initial infections later in 2020 (150-day incidence 0.4%, CI 0.2–0.5% September–October versus 0.2%, CI 0.1–0.3% March–May and 0.3%, CI 0.2–0.3% June–August, p 0.008). In an adjusted Cox proportional hazards model, being female (hazard ratio (HR) 1.44, CI 1.14–1.81), adult (age 18–39, HR 2.71, CI 1.38–5.31, age 40–59 HR 2.22, CI 1.12–4.41, age ≥60 HR 2.52, CI 1.23–5.17 versus <18 years), immunocompromised (HR 2.48, CI 1.31–4.68), hospitalized (HR 1.60, CI 1.07–2.38), and initially infected later in 2020 (HR 2.26, CI 1.38–3.71 September–October versus March–May) were significant independent predictors of suspected reinfection.

Conclusions

Reinfection with SARS-CoV-2 is uncommon, with suspected reinfections more likely in women, adults, immunocompromised subjects, and those previously hospitalized for coronavirus 2019 (COVID-19). This suggests a need for continued precautions and vaccination in patients with COVID-19 to prevent reinfection.

中文翻译：

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一组 PCR 阳性 COVID-19 患者疑似 SARS-Cov-2 再感染的发生率和严重程度

目标

评估疑似严重急性呼吸系统综合症冠状病毒 2 (SARS-CoV-2) 再感染的负担和严重程度。

方法

对 2020 年 3 月 1 日至 2020 年 10 月 31 日期间发生 PCR 阳性 SARS-CoV-2 感染的南加州 Kaiser Permanente 成员的回顾性队列进行了追踪，随后通过电子健康记录进行了 SARS-CoV-2 阳性检测（疑似再感染）≥90 天初次感染后，至 2021 年 1 月 31 日。使用 Kaplan-Meier 方法估计疑似再感染的发生率。Cox 比例风险模型估计了疑似再感染与人口统计学和临床​​特征、住院和初次感染日期的关联。

结果

75 149 人的队列主要是西班牙裔人 (49 648/75 149, 66.1%)，其中女性略多于男性 (39 736, 52.9%)，免疫功能低下的患者很少 (953, 1.3%)；确定了 315 例疑似再感染，270 天的累积发生率为 0.8%（95% 置信区间 (CI) 0.7–1.0%）。疑似再感染 (36/315, 11.4%) 比初次感染 (4094/75 149, 5.4%) 住院更常见。女性（1.0%，CI 0.8-1.2% 与 0.7%，CI 0.5-0.9%，p 0.002）和免疫功能低下患者（2.1%，CI 1.0-4.2% 与 0.8%，CI 0.7-1.0%）的疑似再感染率较高, p 0.004)，且儿童低于成人（0.2%，CI 0.1-0.4% vs 0.9%，CI 0.7-1.0%，p 0.023）。初次感染时住院的患者更有可能怀疑再感染（1.2%，CI 0.6-1.7% vs 0.8%，CI 0.7-1.0%，p 0.030），与 2020 年晚些时候初次感染者一样（150 天发病率 0.4%，9 月至 10 月的 CI 0.2–0.5% 与 0.2%，3 月至 5 月的 CI 0.1–0.3% 和 6 月至 8 月的 0.3%，CI 0.2–0.3%， p 0.008）。在调整后的 Cox 比例风险模型中，女性（风险比 (HR) 1.44，CI 1.14-1.81），成人（18-39 岁，HR 2.71，CI 1.38-5.31，40-59 岁 HR 2.22，CI 1.12-4.41 ，年龄≥60 HR 2.52，CI 1.23–5.17 vs <18 岁），免疫功能低下（HR 2.48，CI 1.31–4.68），住院（HR 1.60，CI 1.07–2.38），并在 2020 年晚些时候首次感染（HR 2.26） 1.38-3.71 9-10 月与 3-5 月）是疑似再感染的重要独立预测因素。

结论

再次感染 SARS-CoV-2 并不常见，女性、成人、免疫功能低下的受试者以及之前因冠状病毒 2019 (COVID-19) 住院的患者中疑似再次感染的可能性更大。这表明需要对 COVID-19 患者采取持续的预防措施和疫苗接种，以防止再次感染。