Coronavirus | April 6, 2022 | FREE
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Rapid testing of health care workers with COVID-19 found many still positive at day 5

Rapid antigen testing for SARS-CoV-2 could be a safe and effective method for guiding return to work, according to the authors of a retrospective study of health care personnel infected in January.

A new study offered support for using rapid antigen testing to determine when health care workers who have had COVID-19 can return to work.

The retrospective cohort study included 1,661 health care personnel (HCP) in Arizona, Florida, Minnesota, and Wisconsin who had a positive test for SARS-CoV-2 between Jan. 3 and Jan. 22, 2022, and were rapid-tested at least once to see if they had cleared the virus. Results were published as a brief report by Clinical Infectious Diseases on March 30.

The first follow-up rapid antigen test was performed a median of six days after the initial positive diagnostic SARS-CoV-2 test, and it was positive in 64.8% (n=1,076). A total of 585 of the HCP with a positive follow-up result took another test a median of seven days after their initial positive test, and 64 completed at least two rapid tests between days 5-9 after the initial positive test. The authors calculated that compared with an isolation period of 10 days, rapid testing to return to work reduced isolation time by two days per person on average. However, on day 5, testing was negative in only 11.9% of the HCP in the study. Positive follow-up tests were more common in those who had reported symptoms at the time of diagnosis (P<0.01).

“Our findings have significant implications for management of infected HCP,” said the study authors. They noted that in December, the CDC offered a contingency option for those with COVID-19 to return to work at five days with or without a negative test but that the study's findings indicate “a significant percentage of infected HCP may continue to shed high concentrations of SARS-CoV-2 during days 5 to 10 after their initial diagnosis. …While these findings do not support a time-based return to work strategy shorter than 10 days, if [rapid testing] resources are limited, it would be reasonable to initiate return-to-work testing later than day 5, especially for employees with symptomatic infection.”

The results show that rapid antigen testing can be safe and effective for guiding clinicians' return to work, said the authors, who called for this to be added to other preventive measures to decrease the possibility of nosocomial SARS-CoV-2 transmission.