COVID-19 has wreaked havoc on every aspect of life. With over 5 million cases and 167 thousand deaths in the United States, COVID-19 has caused the nation to shut down. During the pandemic, social distancing and masks have been crucial in controlling the spread of virus. However, with the reopening of the states, social distancing and masks are not the only factors to consider, especially with talks about children going back to in-classroom education, etc.
Containing the spread of virus requires testing to identify individuals who are infected and contact tracing. Current testing for the active infection relies primarily on polymerase chain reaction (PCR), a technique that looks for the presence of viral RNA, by amplifying the virus’ genetic material making it easier to detect. These tests are highly accurate, with sensitivity and specificity rates of almost 100 percent. PCR, however, requires specialized lab equipment and reagents, and trained personnel. As such, these tests are costly to perform. In addition, they are time-consuming. Currently, many labs are already backlogged, and in some places, taking up to 14 days to report results. While people are waiting for results, many go about their normal lives and continue interacting with others and spreading the virus. Contact tracing becomes nearly impossible to conduct, and many people’s infective period ends before getting results, which make isolation useless by then.
As the nation continues to reopen and individuals develop “pandemic fatigue,” we must address the issue of COVID-19 testing. Adequate testing, which involves increased access to testing and fast turn-around times, is crucial – and if this cannot be done with PCR, alternatives must be considered.
Antigen testing, which detects specific proteins on the virus’ surface, is another technique to test for the active infection. Antigen testing requires the sample to have high enough amounts of viral proteins to yield a positive test, which makes these tests less accurate than PCR. Although antigen testing is highly specific, it is less sensitive than PCR. This means, if a patient tests positive on the antigen test, you can be almost certain the patient is infected. If the patient tests negative, however, the possibility of false-negative must be considered. There are numerous benefits of antigen testing; however, antigen testing is easy to perform, can be done with a nasal swab, yields test results in approximately 20 minutes, and is much cheaper than PCR.
Antigen testing is not a replacement for PCR testing in hospitals or situations where there is high suspicion for infection. Antigen testing could, however, be a screening modality to increase testing to allow for safe reopening, including schools. With frequent testing and quick results, isolation and contact tracing can be done in time to prevent the spread of the virus. This is especially useful in identifying asymptomatic carriers that do not exhibit any symptoms but are capable of spreading the virus to others, who may be more vulnerable to developing severe COVID-19. Although not a replacement for PCR, the antigen test is another test that could help in this pandemic and the safe reopening of the nation.
Christine Lau is a physician.
Image credit: Shutterstock.com
