Dr. Matt Binnicker, an expert in the diagnosis of infectious diseases, discusses the future of Covid-19 testing and explains why we’ll be testing for this viral infection for years to come.
As Covid-19 swept across the globe in 2020, all eyes were on testing for the novel virus. Many asked, “When will testing be available?” then “Where can I get a test?” and subsequently, “How long until my results will be available?” Initially, testing was limited to public health labs and large reference laboratories. In some situations, individuals were waiting over a week for their result, due in part to the global shortage of supplies and the significant backlog of tests. In 2021, access to testing increased as laboratories built up capacity and at-home antigen tests became available. Now in 2022, testing options for Covid-19 are widespread, with the U.S. government shipping free tests to homes nationwide.
Unfortunately, Covid-19 is once again surging in many parts of the country. This suggests that testing for Covid-19 will continue to be important in the future. But what will that be like? And will the approach to testing change?
If you have a respiratory illness, you’ll likely be tested for multiple viruses, including Covid-19
During the first several days of a Covid-19 illness, symptoms are often non-specific and may include a fever, cough, and sore throat. These symptoms can be indistinguishable from other viral infections, such as influenza, respiratory syncytial virus (RSV), or viruses associated with the common cold. Because of this, diagnostic testing can be important, not only to identify the cause of the illness, but also to determine if treatment is appropriate. While common cold viruses and RSV are usually managed with supportive care – rest, hydration, pain medications – there are specific therapies, including antivirals, available for influenza and Covid-19.
Over the last several years, it has become common for lab-based PCR tests to include both influenza and RSV, so that physicians will have results for both viruses when their patient experiences a flu-like illness. During the Covid-19 pandemic, some manufacturers have developed molecular tests that look for influenza, RSV and Covid-19, all in the same test. This approach will become more common and will likely be an option for at-home testing. On May 16, 2022, the FDA authorized the first direct-to-consumer influenza, RSV and Covid-19 test, which allows for patients to collect their swab at home and then send the specimen to a laboratory for testing of all three viruses. In the near future, it is likely that options will become available that allow for complete at-home sample collection and testing for these viruses.
If you don’t have symptoms, you won’t need to test
A somewhat unique feature of the Covid-19 pandemic has been the focus on testing of asymptomatic individuals – i.e., those who lack symptoms. This has been important due to the early observation that asymptomatic carriers can spread the virus, with one study estimating that over 50% of infections result from asymptomatic transmission. Therefore, identifying those who were infected yet asymptomatic was essential in controlling spread of the virus and reducing the chance that high-risk individuals were unknowingly exposed.
Despite the important role of asymptomatic testing during the first several years of the pandemic, this is an uncommon practice and has required tremendous resources to achieve. Asymptomatic individuals are not routinely tested for other respiratory infections, such as influenza, even though transmission in the absence of symptoms can occur. In the future, high rates of natural infection or vaccination, along with the increased availability of effective treatments for Covid-19, will reduce the incidence of severe outcomes and death. Testing of asymptomatic individuals will only occur in rare situations, such as prior to certain procedures or surgeries that place a person at increased risk of a poor outcome if infected.
You’ll be able to perform a highly accurate test from the comfort of home
The Covid-19 pandemic has ushered in a new era of innovation and has likely increased the pace of diagnostic development by 5 to 10 years. Due to stay-at-home orders, remote work and school, and the importance of limited social interaction throughout the pandemic, there has been significant emphasis on the development of at-home sample collection and testing options. There are now multiple Covid-19 antigen tests that can be performed at-home; however, these tests may miss some infections, especially when low levels of the virus are present. In the future, at-home tests that utilize molecular (e.g., PCR) technology will become available and allow for rapid and highly sensitive Covid-19 test results.
If there is a silver-lining to Covid-19, it’s that the pandemic has accelerated a future state where novel diagnostics are more user-friendly, convenient, accessible, and accurate.