No agreed-upon definition exists that spells out exactly which symptoms trigger the need for a test. One expert says that if a get-together includes, for example, someone with Stage 4 cancer, it would be appropriate for all attendees to test beforehand.
Technically, anyone who wants a COVID-19 test can walk into a pharmacy or health care office and get one. In actuality, though, access to the tests has been uneven and questions remain about the accuracy of the various tests. “We know that molecular testing has the highest sensitivity for ruling out—for excluding—COVID,” says Nira Pollock, MD, PhD, a member of the Infectious Diseases Society of America (IDSA), which is keeping tabs on the state of COVID-19 testing. Pollock, who is the associate medical director of the Infectious Diseases Diagnostic Laboratory at Boston Children's Hospital, points out that questions also persist about “turnaround time, with cost, and with supplies facing both patients and laboratories.”
Even as testing has evolved, long lines at health care facilities may persist, Pollock says. It may be hard to get an appointment at a pharmacy, and fewer state testing sites remain open. Supply chain problems mean testing supplies are not always abundant. Samples may be sent to labs that have long turnaround times. And while the tests themselves are free to consumers, office visits may entail copays.
Home testing offers many more conveniences with a potential pitfall: the possibility of a less accurate result. “Most of the available home tests are...antigen rapid diagnostic tests, or RDTs,
and those have significant potential advantages,” says Pollock. These include fast turnaround time and lower costs, at least to third-party providers. Because home tests are relatively cheap and fast, they can be used for serial testing, although there is no consensus on the optimal interval between tests. However, the ability of rapid tests to detect the virus is somewhat reduced compared with that of PCR tests. “There’s still disagreement about whether a negative RDT can effectively rule out infection in a symptomatic individual,” Pollock notes, adding that a person can have a negative antigen test and positive PCR test and be infectious.
One problem with home tests is that people might administer them incorrectly, which could affect results. Another issue is that positive results may not be reported. “I think we will probably lose track,” says Dial Hewlett Jr., MD, FIDSA, an IDSA Fellow and medical director of the Division of Disease Control at the Westchester County Department of Health in New York. “We won’t have as accurate an idea in terms of what the prevalence of the disease is at any given time. On the other hand, I think that having access to these results in a very rapid way will be helpful in terms of the practical issues of going to school.”
Rapid testing may indeed be the key to keeping kids in school, although there are obstacles.
No agreed-upon definition exists that spells out exactly which symptoms trigger the need for a test. There also is no consensus about the need for school testing if transmission rates in an area are low. Pollock mentions the Test and Stay program being piloted in certain districts by the Centers for Disease and Control and Prevention (CDC), which involves regular rapid onsite testing and contract tracing of potentially exposed children and staff so they don’t have to quarantine at home.
While PCR tests catch more positive results than do rapid tests, the lag time between testing and results can be as long as several days. This can be problematic if people don’t quarantine while waiting for results. Hewlett explains that under the vaccine mandate for health care workers, those in his county who receive exemptions must take molecular tests once a week. “The shortcoming of this is that an individual may test negative on Monday and then they may actually start to develop symptoms on Tuesday,” he says. Meanwhile, coworkers are potentially exposed during that time.
For vaccinated but asymptomatic individuals, when and whether to test is more of a nuanced discussion. If a group is planning to gather for the holidays and all are vaccinated, should they all take COVID-19 tests beforehand? The answer depends on whether anyone is vulnerable due to age or comorbidities, the experts agree. “[T]esting in vaccinated people really is a balance of risk--risk for those around you, risk for yourself and your health history, and also access and resources,” Pollock says. Hewlett says that if the gathering includes, for example, someone with Stage 4 cancer, it would be appropriate for all attendees to test before coming together.
The panel’s experts lamented that finances might factor into someone’s decision to get a COVID-19 test. While tests administered at an urgent care center or lab are free to the consumer, reports of third-party bills sent to insurance companies or the government are not unheard of. And rapid tests for home use can start at $25 for a 2-pack and run to $35 or more, which may be out of reach for many families, especially those with multiple children. “The fact that someone with means can more quickly get a test to exclude COVID in their child and get that child back to school than potentially someone without those resources--it just shouldn't be that way,” says Pollock.
Pollock adds that it has been difficult to find rapid tests of late, although the Biden administration has invested heavily in their development and availability, which should make them easier to obtain heading into the winter season.
This article first appeared in Contagion®.