key: cord-0960207-tyrfz0h5
authors: Liu, Michael; Arora, Rahul K.; Krajden, Mel
title: Rapid antigen tests for SARS-CoV-2
date: 2021-03-29
journal: CMAJ
DOI: 10.1503/cmaj.202827
sha: 6be0417f41d9c4f1325975eda33869eb4cb831ea
doc_id: 960207
cord_uid: tyrfz0h5

nan

People who have asymptomatic or presymptomatic infections may account for more than half of SARS-CoV-2 transmissions, but are often ineligible for diagnostic testing unless they have been in close contact with a confirmed case. 4 Screening programs that use RATs target people who are asymptomatic to rapidly identify those with high viral loads, which is especially important for preventing onward transmission in highrisk and congregate settings. 5,6

For people with higher pretest probability of SARS-CoV-2 infection (e.g., people who are symptomatic or have had recent exposure, or in settings with high prevalence of infection), positive RAT results should be managed as confirmed cases. Results could be falsely negative in people with low viral loads and should be confirmed by RT-PCR. For people with lower pretest probability, positive RAT results should initially be managed as confirmed cases, with results verified by RT-PCR to rule out false-positive results. Negative results in this group could mean either no infection or an infection with a low viral load, so people should continue usual public health measures to avoid acquiring and transmitting infection.

Proper training in sample collection improves test sensitivity and accuracy. 6 Personnel must also be trained in the use of personal protective equipment and appropriate biosafety to prevent infection while obtaining and handling samples. 

Michael Liu AB, Rahul K. Arora BHSc, Mel Krajden MD 

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