Objective To assess the incidence of COVID-19 infection in the absence of a confirmatory test in persons suspecting they contracted COVID-19 and elucidate reasons for their belief. Methods We recruited persons with a confirmed COVID-19 diagnosis and persons who believed they may have contracted COVID-19 between December, 2019 and April, 2021 into a study of immunity against SARS-CoV-2. An intake questionnaire captured their perceived risk factors for exposure and symptoms experienced, including symptom duration and severity. ELISA testing against multiple SARS-CoV-2 antigens was done to detect antibodies against SARS-CoV-2. No participant had received COVID-19 vaccination prior to the time of testing. Results The vast majority of study subjects without Public Health confirmation of infection had no detectable antibodies against SARS-CoV-2. Suspected infection with SARS-CoV-2 generally involved experiencing symptoms common to many other respiratory infections. Unusually severe or persistent symptoms often supported suspicion of infection with SARS-CoV-2 as did travel or contact with travelers from outside Newfoundland and Labrador. Rare cases in which antibodies against SARS-CoV-2 were detected despite negative results of Public Health testing for SARS-CoV-2 RNA involved persons in close contact with confirmed cases. Conclusions Broad public awareness and declaration of pandemic status in March, 2020 contributed to the perceived risk of contracting COVID-19 in Newfoundland and Labrador from late 2019 to April 2021 and raised expectation of its severity. Serological testing is useful to diagnose past infection with SARS-CoV-2 to accurately estimate population exposure rates.
【초록키워드】 COVID-19, SARS-CoV-2, Immunity, antibody, severity, Infection, Symptom, COVID-19 vaccination, symptom duration, COVID-19 diagnosis, Travel, SARS-CoV-2 RNA, SARS-CoV-2 antigen, questionnaire, diagnose, close contact, Contact, Perceived risk, Factor, subject, confirmed cases, other respiratory infections, pandemic status, ELISA testing, Public, objective, Result, detect, involved, recruited, Suspected, detectable, raised, supported, majority, absence, contributed, had no, was done, incidence of COVID-19, infection with SARS-CoV-2, 【제목키워드】 SARS-COV-2 infection, Public, absence,