By Vishwadha Chander
(Reuters) – Abbott Laboratories’ rapid COVID-19 antigen test is highly likely to correctly detect if people have ever contracted the virus and could help with earlier isolation, according to the U.S. Centers for Disease Control and Prevention.
The test was less sensitive in detecting asymptomatic infection, but the CDC study found that the faster turnaround time can help limit transmission by more rapidly identifying infectious persons for isolation. (https://bit.ly/38WwExa)
The study comes when public health departments are scrambling to implement strategies to reduce or prevent the rapid spread of the virus, with the United States recording more than 200,000 new cases and 3,220 deaths on average over the last seven days.
Several rapid antigen tests have been approved by the U.S. Food and Drug Administration for emergency use, but data lacks on test performance in asymptomatic people, according to a team of scientists from CDC’s COVID-19 Response Team and the Arizona Department of Health Services.
Using the real-time reverse transcription–polymerase chain reaction, or RT-PCR, test as the standard, the CDC studied over 3,400 specimens collected from people aged over 10 years at two community testing sites in Pima County, Arizona, from Nov. 3 to Nov. 17.
Compared with RT-PCR, Abbott’s BinaxNOW antigen test had a sensitivity of 64.2% for specimens from symptomatic people and only 35.8% for specimens from asymptomatic people.
It had near 100% specificity in specimens from both groups, suggesting very few false positives and no false negatives.
“BinaxNOW is great at finding infectious people – and this Pima County study demonstrates that BinaxNOW is 92.6% effective at identifying positive cases when people are infectious – in line with our performance data,” Abbott said in an emailed statement.
The researchers said swabs from the back of the nose were taken for the RT-PCR tests, which might have contributed to increased detection for the real-time RT-PCR assay. Swabs from the front of the nose were used for BinaxNOW.
(Reporting by Vishwadha Chander in Bengaluru; Editing by Sriraj Kalluvila)
