Prolonged COVID test positivity in symptomatic, Omicron BA.2 infectionsAmong a group of vaccinated college athletes who tested positive for COVID-19 and underwent rapid antigen testing 7 days later, 27% were still positive—a proportion that climbed to 35% in symptomatic athletes and 40% in those infected with the Omicron BA.2 subvariant.The findings, published yesterday in JAMA Network Open, suggest that rapid antigen testing may help prevent still-positive people from leaving isolation while still infectious, the Stanford University authors said.
The US Centers for Disease Control and Prevention (CDC) currently recommend 5 days of isolation followed by 5 days of wearing a well-fitting mask after a COVID-19 diagnosis.The researchers studied Stanford athletes who tested positive for COVID-19 from Jan 3 to May 6, 2022, and had received the primary series of the Pfizer/BioNTech, Moderna, or Johnson & Johnson vaccines at least 2 weeks earlier.
Seven days later, the athletes began rapid antigen testing to determine if isolation was still needed. They also completed symptom questionnaires.According to campus wastewater data, 68% of infections occurred when the BA.1 variant was dominant, and 32% occurred during BA.2 dominance.A total of 264 athletes had 268 infections, with 66% of them symptomatic.
Average age was 20.1 years, and 53% were women. Most students (representing 248 infections) underwent rapid antigen testing on day 7, and 27% of them were still positive.