BinaxNOW, the rapid point-of-care antigen test from Abbott Laboratories, Chicago, may miss nearly two-thirds of covid-19 infections in people without symptoms, according to a study from the CDC.1 However, the study also showed that BinaxNOW catches most infectious cases.
The researchers used BinaxNOW and PCR to analyze 3,419 paired specimens collected at two community testing sites in Pima County, Ariz, between November 3 and 7, 2020. Compared to PCR, BinaxNOW had a sensitivity of 64.2% for specimens from symptomatic persons and 35.8% for specimens from asymptomatic persons, with near 100% specificity in specimens from both groups.
A statement from Abbott stated that “BinaxNOW is great at finding infectious people—and this Pima County study demonstrates that BinaxNOW is 92.6% effective at identifying infectious people who are symptomatic and 78.6% when they are asymptomatic. Equally as important, these data show that if a patient has no symptoms and they have a negative result, BinaxNOW will give the right answer 96.9% of the time.”
According to the CDC, “Despite their reduced sensitivity to detect infection compared with real-time RT-PCR, antigen tests might be particularly useful when real-time RT-PCR tests are not readily available or have prolonged turnaround times. Persons who know their positive test result within 15 to 30 minutes can isolate sooner, and contact tracing can be initiated sooner and be more effective than if a test result is returned days later. “
Read more from Abbott.
- Prince-Guerra JL, Almendares O, Nolen LD, et al. Evaluation of Abbott BinaxNOW Rapid Antigen Test for SARS-CoV-2 Infection at Two Community-Based Testing Sites — Pima County, Arizona, November 3–17, 2020. MMWR Morb Mortal Wkly Rep. 2021;70(3):100-105. doi: 10.15585/mmwr.mm7003e3.