Experts Outraged Over CDC Rollback on Asymptomatic COVID-19 Testing

White woman's hands holding a COVID-19 test tube and swab.


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On September 18, the Centers for Disease Control and Prevention (CDC) reversed its highly-criticized stance, once again calling for the testing of asymptomatic individuals who may have been exposed to COVID-19.

"Due to the significance of asymptomatic and pre-symptomatic transmission, this guidance further reinforces the need to test asymptomatic persons, including close contacts of a person with documented SARS-CoV-2 infection," the updated testing guidelines say.

On August 24, the Centers for Disease Control and Prevention (CDC) released updated guidelines for COVID-19 testing. The agency is now advising that people who do not have symptoms do not get tested—even if they have been exposed to COVID-19. The CDC did not offer a justification for the change.

The shift in testing protocols prompted concern from scientists and public health officials. Widespread testing of both symptomatic and asymptomatic individuals has been a cornerstone of the pandemic’s containment efforts.

“This walk back is a threat to public health and the gains we’ve made,” William Li, MD, a physician scientist in Cambridge, Massachusetts, tells Verywell.

The CDC's new guidelines state that people who have close contact with someone infected with COVID-19 “do not necessarily need a test.” Close contact is defined as within six feet for 15 minutes or longer.

Exceptions to the amended guidelines apply to healthcare workers and “vulnerable” populations, such as older people and people with underlying health conditions that put them at risk for severe disease.

Anthony Fauci, MD, the director of the National Institute of Allergy and Infectious Diseases, stated that he was not involved in the decision-making process, as he was undergoing a procedure to remove a polyp from his vocal cord when the CDC’s revisions went live. 

Why Testing Widely Matters

Research has indicated that when a person is exposed to someone infected with COVID-19, they typically enter a brief presymptomatic period. The stage accounts for the window between exposure to SARS-CoV-2 (the virus that causes COVID-19) and the development of symptoms (if they develop any).

William Li, MD

Asymptomatic people can be super spreaders, and by not testing them we are unable to spot the threat and contain it. This is like reversing TSA airport security at the time of a known terrorist threat.

— William Li, MD

While the CDC's updated guidelines downplay the importance of the presymptomatic stage, a study on the patterns of transmissibility demonstrated that 44% of SARS-CoV-2 infections stem from this phase.

“Significant presymptomatic transmission would probably reduce the effectiveness of control measures that are initiated by symptom onset, such as isolation, contact tracing, and enhanced hygiene or use of face masks for symptomatic persons,” the authors of the study, published in April in the journal Nature Medicine, write.

Presymptomatic people still carry a heavy viral load (the amount of a virus’ genetic material in a person's system) even if they never develop symptoms. People can easily—and unknowingly—spread the virus to others, and health officials have no means to track or trace the root of the virus' circulation. 

According to the CDC, up to 40% of people infected with COVID-19 do not develop symptoms.

Li, who is the president and medical director of the Angiogenesis Foundation, a disease prevention nonprofit, says that waiting to test until someone is very ill will lead to more severe disease developing in the community.

However, some people never develop COVID-19 symptoms at all. According to the CDC, 40% of infected individuals remain asymptomatic throughout the course of their infection.

“Asymptomatic people can be super spreaders, and by not testing them we are unable to spot the threat and contain it," Li says. "This is like reversing TSA airport security at the time of a known terrorist threat."

What This Means For You

The revised CDC guidelines could set the U.S. back in its efforts to control the spread of the SARS-CoV-2 virus. If you have been exposed to someone with COVID-19, talk to your healthcare provider. Even if you are not considered a "vulnerable person" based on the CDC's criteria, your provider might still recommend that you get tested.

CDC Change Clashes With Other Protocols 

The World Health Organization (WHO) takes a different stance on COVID-19 testing. In a report titled “Laboratory testing for 2019 novel coronavirus (2019-nCoV) in suspected human cases,” the WHO states that the decision to test should be guided by the chances of infection, which is to be determined using both clinical and epidemiological information.

Susan R. Bailey, MD

Suggesting that people without symptoms, who have known exposure to COVID-positive individuals, do not need testing is a recipe for community spread and more spikes in coronavirus.

— Susan R. Bailey, MD

“PCR testing of asymptomatic or mildly symptomatic contacts can be considered in the assessment of individuals who have had contact with a COVID-19 case,” the report says. 

In response to the CDC's new guidelines, The American Public Health Association (APHA) released a statement on August 27 emphasizing that the revised approach could endanger lives.

“We are also concerned that this change was made without effective consultation with public health professionals who are on the ground managing this outbreak," APHA Executive Director George C. Benjamin, MD, said in the statement. "It makes the messaging confusing and may reduce access for those needing testing. Lack of access to adequate testing has been a significant barrier to getting effective disease control of this pandemic."

The American Medical Association (AMA) released a statement on August 26 urging the CDC to not only rethink its decision but provide scientific justification for the modification.

“Suggesting that people without symptoms, who have known exposure to COVID-positive individuals, do not need testing is a recipe for community spread and more spikes in coronavirus,” AMA President Susan R. Bailey, MD, says in the statement.

The Infectious Disease Society of America (IDSA) called for the immediate reversal of the CDC’s revision in an August 26 statement, stressing the role that asymptomatic people play in the spread of SARS-CoV-2. The IDSA referenced its own diagnostic guidelines, which urge asymptomatic people with confirmed exposure to COVID-19 to get tested.

The World Health Organization, The American Public Health Association, The American Medical Association, and The Infectious Disease Society of America have all expressed concerns about the CDC's updated guidelines and the implications of scaled-back testing.

Consequences of Reduced Testing

Li emphasizes that the effect of confining testing to strictly symptomatic populations could have many ramifications for the U.S.—especially in educational institutions. 

As schools and colleges struggle to re-open, with communities of younger people who are more likely to be asymptomatic, this flip-flop on recommendations will make concerted efforts to get in-person education even more difficult, especially as many schools have taken on testing,” Li says. 

Internationally, differences in testing protocols are reflected in the reduced COVID-19 transmission rates.

For example, South Korea prioritized testing for both asymptomatic and symptomatic people before the pandemic even reached its peak. The country implemented widespread testing in early February and has used the results to focus on quarantining all infected individuals and implement contact tracing. 

In mid-March, the number of cases in South Korea had reached its apex, and the country had flattered its curve with no more than 600 cases a day.

The U.S. only started implementing testing measures in mid-March. By early April, the number of infected cases was 50 times higher than the numbers South Korea saw at its peak. 

As of September 1, South Korea has had a total of 20,182 confirmed cases since the start of the pandemic. The U.S. has over 6 million. 

South Korea’s focus on mass testing for anyone exposed to the virus, regardless of symptoms, has been one of the main factors responsible for its ability to control the spread of the virus. 

“Surveillance testing is what every country that has gotten a grip on the pandemic has used in combination with contact tracing,” Li says. “Testing is a critical part of control, and we absolutely need to make more testing available. All of these steps are needed to curb transmission so we can restore our society.”

In a special report published in the New England Journal of Medicine in July, scientists from the National Institutes of Health (NIH) announced an initiative to create a framework for more frequent and universal testing. The authors discussed the necessity of increasing the number of tests given to underserved populations, with the aim of creating 6 million cheap and rapid tests. 

However, the CDC is not aligned with this goal, and is now reducing testing to a smaller population of people.

What Should You Do If You're Exposed But Asymptomatic?

Even if you can't get tested right away, you shouldn't just wait it out if you believe you've been exposed to COVID-19, Li says.

“Whether or not [they have] symptoms, anyone who has had close contact with someone who is confirmed COVID-19-positive needs to get in touch with their doctor to seek advice on the need for testing and the need for quarantine or isolation,” he says. “Anyone who has close contact with an individual who is sick from active COVID-19 needs to take action.”

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

13 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention (CDC). Overview of testing for SARS-CoV-2 (COVID-19).

  2. Chappell B. Dr. Anthony Fauci has surgery to remove a polyp from vocal cord. NPR.

  3. He X, Lau EHY, Wu P, Deng X, Wang J, Hao X. Temporal dynamics in viral shedding and transmissibility of COVID-19Nat Med 26, 672–675. doi:10.1038/s41591-020-0869-5

  4. He X, Lau EHY, Wu P. et al. Temporal dynamics in viral shedding and transmissibility of COVID-19Nat Med 26, 672–675. doi:10.1038/s41591-020-0869-5

  5. Furukawa NW, Brooks JT, Sobel J. Evidence supporting transmission of severe acute respiratory syndrome coronavirus 2 while presymptomatic or asymptomaticEmerging Infectious Diseases. 26(7). doi:10.3201/eid2607.201595

  6. Centers for Disease Control and Prevention. COVID-19 pandemic planning scenarios.

  7. World Health Organization (WHO), Department of Communications, WHO Global. Laboratory testing for 2019 novel coronavirus (2019-nCoV) in suspected human cases (WHO/COVID-19/laboratory/2020.5).

  8. American Public Health Association. New COVID-19 testing advice could endanger lives.

  9. American Medical Association. AMA statement on CDC changes to COVID-19 testing guidance.

  10. Infectious Diseases Society of America. IDSA/HIVMA statement on changes to CDC guidance.

  11. Hasell J. Testing early, testing late: four countries’ approaches to COVID-19 testing compared. Our World in Data.

  12. The New York Times. Coronavirus in the U.S.: Latest map and case count.

  13. Tromberg BJ, Schwetz TA, Pérez-Stable EJ, Hodes RJ, Woychik RP Bright, RA. Rapid scaling up of Covid-19 diagnostic testing in the United States — The NIH RADx InitiativeN Engl J Med. doi:10.1056/NEJMsr2022263