Katherine J. Wu  

The New York Times logo C.D.C. Now Says People Without Covid-19 Symptoms Do Not Need Testing

The Centers for Disease Control and Prevention quietly modified its coronavirus testing guidelines this week to exclude people who do not have symptoms of Covid-19 — even if they have been recently exposed to the virus.

a man standing next to a door: “If people are getting exposed, and they’re not getting tested, and they’re not isolating, that’s a huge problem,” one doctor said.© Adriana Zehbrauskas for The New York Times “If people are getting exposed, and they’re not getting tested, and they’re not isolating, that’s a huge problem,” one doctor said.

Experts questioned the revision, pointing to the importance of identifying infections in the small window immediately before the onset of symptoms, when many individuals appear to be most contagious.

Models suggest that about half of transmission events can be traced back to individuals still in this so-called pre-symptomatic stage, before they start to feel ill — if they ever feel sick at all.

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“This is potentially dangerous,” said Dr. Krutika Kuppalli, an infectious disease physician in Palo Alto, Calif. Restricting testing to only people with obvious symptoms of Covid-19 means “you’re not looking for a lot of people who are potential spreaders of disease,” she added. “I feel like this is going to make things worse.”

At a moment when experts have almost universally come forward to encourage more frequent and widespread testing, especially to reach vulnerable and marginalized sectors of the population, the