ABSTRACT
Background: Coronavirus disease 2019 (COVID), a respiratory illness (RI) caused by SARS-CoV-2 (CoV2) was first reported in Wuhan, China in December 2019. It spread rapidly and the US confirmed its first case in January 2020. Due to the novelty of CoV2 and COVID, little was known about the epidemiology, clinical course, and diagnostic methods. Since then, studies have shown that CoV2 originated from bats and COVID may have pre-existed undiagnosed outside China before the cases were first reported. Our aim was to evaluate the prevalence of CoV2 in autopsy cases at our institution, where autopsy was not performed on known COVID cases. Design: We searched our pathology database for adult autopsies performed on the lungs and heart in our institution from 6/1/19 - 6/30/20. Cases were divided into groups by cause of death (COD) possibly related to COVID, presence of a clinical RI, and autopsy findings of pneumonia (Pnx). CODs possibly related to COVID (COVID-possible) included bronchopneumonia and multisystem organ failure and CODs unlikely related to COVID (COVID-unlikely) included conditions such as acute myocardial infarction. Total RNA was extracted from archived formalin-fixed-paraffin-embedded (FFPE) lung tissue of all COVID-possible cases and COVID-unlikely cases with Pnx using a commercial kit and following the instructions in the kit. CoV2 RNA was tested for using CDC 2019-nCoV Real-Time RT-PCR Diagnostic Panel, testing the N1 region of the CoV2 genome and an RNA integrity control during amplification. An extracted CoV2 sample from our State Department of Health was used as positive control. Results: 88 cases were included;44 males and 44 females with an average age of 66 years. 42/88 (48%) cases were considered COVID-possible with 24/42 (57%) showing RI and/or Pnx. COVID as COD was considered unlikely in 46/88 (52%) with 34/46 (74%) showing no RI or Pnx. See Table 1. CoV2 PCR was performed on a total of 49 cases: 42 COVID-possible and 7 COVID unlikely with Pnx. CoV2 PCR was negative in all 49 cases with appropriate positive control and RNA integrity in all cases. Conclusions: In our single-institution autopsy cohort, CoV2 was not detected in FFPE lung tissue from any cases without a clinical diagnosis of COVID. Our data suggest that patients in our community who died between 6/1/2019 and 06/30/2020 without known COVID were unlikely to have had sub clinical and/or undiagnosed COVID. Therefore, clinical examination and accurate laboratory testing likely identify the majority of cases of COVID.