Underuse of COVID-19 Testing Appears to Be Contributing to Outbreaks
Relatively few Americans seek out COVID-19 testing, even if they start running a fever, according to a new survey. That problem is especially acute among certain cohorts and appears to help fuel novel coronavirus outbreaks, study authors suggest. What can be done about it?
SAN FRANCISCO – Underuse of novel coronavirus testing appears to have contributed to preventable transmission during the COVID-19 surge over the winter, and that could occur again if uptake of testing doesn’t improve, according to a new study.
The report in JAMA Network Open points out that active SARS-CoV-2 transmission continues in the United States and it has been unclear whether better access to coronavirus testing and more consistent use of testing could substantially reduce that.
University of California San Francisco-led researchers sought to describe coronavirus testing in persons with new onset of febrile illness and analyze whether there are changes over time and differences by race and ethnicity.
In conducting their cohort study, the authors used data from the COVID-19 Citizen Science Study, launched in March 2020, which recruited participants via press release, word-of-mouth, and partner organizations. For Citizen Science, adult participants who have a smartphone completed daily surveys about COVID-19 symptoms and weekly surveys about coronavirus testing.
Included in the current analysis were U.S. participants with new onset of febrile illness from April 2020 to October 2020, with data analysis was performed from November 2020 to March 2021. The 2,679 respondents had a mean age of 46.3 and most were female and college-educated.
Researchers focused on receipt of a coronavirus test result within 7 days of febrile illness onset. They report that 3,865 distinct new febrile illness episodes were reported -- 300 episodes [7.8%] from Hispanic participants, 71 episodes [1.8%] from Black participants, and 3,494 episodes [90.4%] from not Black, not Hispanic participants -- between April 2 and October 23, 2020.
The study notes that, in weekly surveys sent out during the 14 days after fever onset, 12% overall (753 participants) indicated that they had received a COVID-19 test result. Using serial survey responses and parametric time-to-event modeling, researchers as estimated that, by 7 days after onset of febrile illness, 20.5% (95% CI, 19.1%-22.0%) had received a test result.
“This proportion increased from 9.8% (95% CI, 7.5%-12.0%) early in the epidemic to 24.1% (95% CI, 21.5%-26.7%) at the end of July, but testing rates did not substantially improve since then, increasing to 25.9% (95% CI; 21.6%-30.3%) in late October at the start of the winter surge,’ the authors explained.
They add that Black participants reported receiving a test result about half as often as other respondents -- (7% [7 of 103] vs; 12% [53 of 461] for Hispanic vs 13% [693 of 5516] for not Black, not Hispanic; P = .03) – although the association was not statistically significant.
“Systematic underuse of coronavirus testing was observed in this cohort study through late October 2020, at the beginning of the winter COVID-19 surge, which may have contributed to preventable coronavirus transmission,” the researchers conclude.
The authors say they are not sure of the factors contributing to the problem, whether lack of testing availability, knowledge about how to get a test, understanding about the importance of testing, or active avoidance, e.g., to avoid economic hardships associated with isolation and quarantine of contacts if one tests positive.
“We cannot know for certain what the impact of more effective targeting of coronavirus testing would be on disease transmission in the U.S., how it might have blunted the 3rd wave that recently swept through the U.S. or how it might be used to reduce transmission of new coronavirus variants,” they write. “However, it is clear that countries such as China27 and South Korea28,29 have a much more aggressive targeted approach to testing and appear to have substantially lower community transmission rates.”
The study suggests the issuance of clear guidelines with well-resourced public health service announcements targeted to both clinicians and the public. The authors also emphasize the importance of adequate test capacity and convenience, and provision of resources to mitigate the hardships of isolation and quarantine that come with a positive test. They suggest those measures “are all likely to reduce barriers to coronavirus testing and increase the likelihood of identifying new infections in the community and reducing transmission in the U.S.”
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