As the pressure to reopen the economy intensifies, business leaders are searching for ways to reduce the risk of COVID-19 infection for their workers and customers. An alluring idea is to offer testing on site, keeping those who are positive out of the workplace.
Testing seems to offer a combination of confidence building for employees and liability protection for companies. Some employers are even pursuing mandatory testing, which is permitted by the U.S. Equal Employment Opportunity Commission.
So, should universal testing in the workplace become part of the new normal?
Not yet. Given technical and resource limitations, testing is no more than one piece of the puzzle of infection prevention and control. There are three major reasons why it would be a mistake for employers to rely heavily or exclusively on testing for safety:
Social distancing vital even with tests
►Sufficient testing is difficult to put in place at even moderate scale. Testing for active SARS-CoV-2 infection is based on identifying the genetic material of the virus in a sample taken from the back of the throat or the nose. (Saliva testing also is promising.) For one person at a time, with certain machines, results are possible within as little as 15 minutes. When dozens or hundreds of samples are needed, however, samples need to be run in tandem on larger machines, and the results are likely to take hours.
If you ask people to wait a day for the results, that’s another day when latent infection could manifest itself, and another test would be needed. And so on. New rapid “antigen” tests are unlikely to solve this problem, given weaknesses with their accuracy.
Pooling saliva samples from the whole workplace is a potential way to search for the coronavirus at lower cost. This strategy, however, takes additional time for sample collection and laboratory work. It also requires follow-up testing should the pooled sample prove positive.
►Negative test results do not eliminate the risk of COVID-19 transmission in the workplace. The accuracy of the test depends on when it is performed in an individual’s course of infection. Many asymptomatic people with SARS-CoV-2 infection could test negative — especially if they are in the pre-symptomatic but infectious phase. As a result, even the world’s most robust testing program would not eliminate the need for social distancing within an office or retail setting. One missed infection in someone who attends a packed staff meeting will require the whole office to quarantine.
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►Employer testing at scale could lead to shortages of testing supplies and compromise the ability of health care facilities to test people who develop symptoms. Consultants offering testing to businesses may go straight to suppliers of swabs, reagents and testing machines and outbid public health agencies and clinics. If even a fraction of workplaces attempts regular testing, the demands could far exceed capacity.
Less testing of those at greatest risk of infection will mean fewer opportunities for isolation, contact tracing and quarantine, the core components of controlling community spread. As cases in a community rise, so too will the likelihood of infections penetrating every workplace.
Sick leave, screenings and ventilation
Rather than as a magic wand, employers should look at testing as a potential piece of a comprehensive infection prevention and control strategy.
Employers should provide generous sick leave and quarantine benefits, screen employees and customers for symptoms before they come to the workplace, and reengineer the work environment to maintain at least 6 feet of distance and high levels of ventilation. They should focus on ways to promote hand hygiene, social distancing, environmental disinfection, and rapid identification and contact tracing for employees who develop COVID-19.
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Regular testing is most appropriate for small cohorts of people who are unable to socially distance at work and who are exposed to the public in close quarters. Indeed, such testing could prove to be of high utility in very high-risk settings, such as nursing homes. Broad testing is also important in the setting of an outbreak, as directed by public health agencies.
Testing alone, however, is insufficient as an infection prevention and control strategy. A test might find the novel coronavirus, but only careful planning, policy changes, reengineering the workplace and social distancing can stop it from spreading. There are no shortcuts to defeating COVID-19.
Dr. Joshua Sharfstein is vice dean for Public Health Practice and Community Engagement at the Johns Hopkins Bloomberg School of Public Health. Follow him on Twitter:@drJoshS. Dr. Lisa Maragakis is the senior director of Infection Prevention of The Johns Hopkins Health System.