As more at-home COVID-19 tests become available in Connecticut, what role will they play in disease surveillance?
Rapid at-home antigen tests that can be used to quickly identify COVID-19 infections are still in short supply overall, but state and federal officials say more test kits are on the way.
President Joe Biden announced Thursday that his administration will buyan additional 500 million at-home tests to be distributed for free to households across the country. This adds to an initial 500 million tests ordered in a plan detailed last month on how to combat the latest surge of COVID-19 infections.
As Connecticut residents begin to diagnose themselves more frequently, public health experts predict that the at-home tests may one day be incorporated into how the state monitors future outbreaks and transmission.
But for now, most at-home or self-test positive results go undocumented. The state Department of Public Health confirmed that it is not tracking those cases, and people are not required to report their results to local health departments.
“When case rates are as high as they are now with omicron, we’re not going to learn much more from people reporting positives from home than we know already,” said Dr. Sten Vermund, dean of the Yale School of Public Health. “We already know that rates are off-the-charts high.”
The state’s daily positivity rate of new COVID-19 cases has hovered between 20 to 24% for the last week. Statewide transmission has not been so high since the beginning of the pandemic in spring 2020.
Public health experts agree that widespread testing has become a critical component of managing the pandemic. That’s been especially true in identifying early outbreaks. The majority of cases recorded by the state, and used to determine daily positivity rates, have come from laboratory-confirmed tests.
Vermund, who is a pediatrician and epidemiologist, said tracking at-home test results and incorporating them into disease surveillance may be most beneficial in the future, when statewide transmission declines.
“You gain more from reporting positives in the doctor’s private office or in the ER or at home when case rates are low,” he said, “because that can be very helpful in identifying pockets of ongoing transmission.”
Lack of data on at-home test usage and results is not unique to Connecticut. Other states, regions and cities across the U.S. have confirmed they are not tracking at-home results as the costs of setting up comprehensive reporting systems may outweigh any current benefits.
But some infections diagnosed at home are still having an impact on disease surveillance and helping public health officials make decisions.
Megan Westcott, epidemiologist at the West Hartford-Bloomfield Health District, said both public and non-public schools are required to report all positive cases to DPH, and that includes at-home tests.
“This is helpful in tracking case counts and gauging transmission among families within the schools and those associated with extracurricular activities,” Westcott said.
COVID-19 surveillance can be more difficult and complex when it comes to the general public, Westcott said, but some cases are being recorded when residents report at-home positive results to their local health departments in phone calls and emails.
She added that restaurants and congregate living facilities are also required to report positive cases, including those diagnosed with at-home tests, which are then submitted to the state surveillance system.
“While imperfect, reporting from schools, restaurants and available lab testing does provide a clear picture of current trends and outbreak awareness,” Westcott said.
Vermund said demand for more convenient and cheaper at-home tests may rise even more over time, compared to other kinds of in-person molecular or antigen tests that require laboratory analysis and can cost up to $150 without insurance.
If and when there is a more significant shift toward using at-home tests over others, Vermund said it could serve as a possible motive for health agencies to create voluntary reporting systems for people to document their results, especially positive cases.
“It might be incomplete, many people may fail to participate,” he said, “but if we were to harvest a subset of all those tests, we might still have meaningful surveillance data.”
DPH said the state currently has no plans to track at-home COVID-19 test results.
“Over time, burden on the health care system through hospitalizations from COVID-19 will be more important to assess than tracking all cases that occur in the state,” spokesperson Chris Boyle said in an email.
The department does recommend thatpeople who test positive at home notify their health care providers and their workplaces, daycares, schools or other close contacts of their results.