Ramos Kathleen J, Kapnadak Siddhartha G, Collins Bridget F, Pottinger Paul S, Wall Richard, Mays James A, Perchetti Garrett A, Jerome Keith R, Khot Sandeep, Limaye Ajit P, Mathias Patrick C, Greninger Alexander
Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, University of Washington Medical Center, Seattle, WA, USA.
Division of Allergy & Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.
Respir Med Case Rep. 2020 Jun 8;30:101120. doi: 10.1016/j.rmcr.2020.101120. eCollection 2020.
Real-time polymerase chain reaction (RT-PCR) detection of severe acute respiratory syndrome coronavirus (SARS-CoV-2) is required for diagnosis of coronavirus disease 2019 (COVID-19). Sensitivity of RT-PCR nasopharyngeal (NP) testing is presumed to be high, but there is no gold standard against which this has been determined. The objective was to determine whether lower respiratory tract infection (LRTI), detected in bronchoalveolar lavage fluid (BALF), occurs in the absence of upper respiratory tract infection with clinical testing of both specimen types.
Between March 26, 2020 and April 17, 2020 at the University of Washington Medical Center all patients with BALF specimens clinically tested for SARS-CoV-2 were identified. We assessed the proportion of patients with positive RT-PCR for SARS-CoV-2 in BALF after negative NP testing. We describe 3 cases with positive testing in BALF.
Among 16 patients with BALF samples, 3 cases (19%) had SARS-CoV-2 detected in BALF. In Case 1, negative NP testing occurred early in the infection and respiratory symptoms may have been missed due to neurologic injury. In Case 2, outpatient diagnosis was aspiration pneumonia, but clinical suspicion remained high for COVID-19 at hospitalization based on epidemiological and clinical features. All 3 cases involved older adults (age >65 years), one of whom was immunosuppressed in the setting of lung transplantation (Case 3).
These data demonstrate that SARS-CoV-2 LRTI occurs in the presence of negative NP testing. NP testing may underestimate the prevalence of COVID-19 and has implications for spread of SARS-CoV2 in the community and healthcare setting.
2019冠状病毒病（COVID-19）的诊断需要通过实时聚合酶链反应（RT-PCR）检测严重急性呼吸综合征冠状病毒2（SARS-CoV-2）。RT-PCR鼻咽（NP）检测的灵敏度被认为很高，但尚无用于确定此检测灵敏度的金标准。目的是通过对两种标本类型进行临床检测，确定在没有上呼吸道感染的情况下，支气管肺泡灌洗（BALF）中是否会出现下呼吸道感染（LRTI）。
在2020年3月26日至2020年4月17日期间，在华盛顿大学医学中心识别出所有接受SARS-CoV-2临床检测的BALF标本患者。我们评估了NP检测结果为阴性后，BALF中SARS-CoV-2 RT-PCR检测呈阳性的患者比例。我们描述了3例BALF检测呈阳性的病例。
在16例有BALF样本的患者中，3例（19%）BALF中检测到SARS-CoV-2。在病例1中，感染早期NP检测结果为阴性，由于神经损伤可能漏诊了呼吸道症状。在病例2中，门诊诊断为吸入性肺炎，但基于流行病学和临床特征，住院时对COVID-19的临床怀疑仍然很高。所有3例均为老年人（年龄>65岁），其中1例在肺移植后处于免疫抑制状态（病例3）。
这些数据表明，在NP检测结果为阴性的情况下会出现SARS-CoV-2 LRTI。NP检测可能低估了COVID-19的患病率，并对SARS-CoV-2在社区和医疗机构中的传播产生影响。
