The Centers for Disease Control and Prevention quietly changed its COVID-19 testing guidelines this week; it now says those with no coronavirus symptoms need not get tested—even if they've had a recent exposure to the virus. "This is potentially dangerous," one infectious disease physician tells the New York Times. "I feel like this is going to make things worse." A clinical microbiologist calls the move "very strange," and a mathematician and infectious diseases modeler goes with "bizarre." Experts are pointing to the fact that around 50% of transmission events can be traced to pre-symptomatic or asymptomatic people. Most experts have been encouraging more testing, not less. "It seems as though this new guidance is actively discouraging people from seeking testing, even if they have a known exposure," one of those experts, a research scientist, tells NBC News.
Previous testing guidelines recommended testing for all close contacts of infected people (typically defined as within six feet for at least 15 minutes); the new guidelines say close contacts who don't have symptoms "do not necessarily need a test." If they're vulnerable, or if health care providers or health officials recommend testing, an exception would be made, the guidelines say. "Wow, that is a walk-back," the microbiologist says. The guidelines also do not mention self-quarantining for close contacts, though different guidelines do. "If people are getting exposed, and they’re not getting tested, and they’re not isolating, that’s a huge problem," says the infectious disease physician. Another expert tells CNN the changes could derail contact tracing efforts. When questioned about speculation that the CDC move might have been an attempt to address ongoing test supply shortages, a Health and Human Services rep denied the idea and said testing levels have not even hit capacity. "We revised the guidance to reflect current evidence and the best public health interventions." (Read more coronavirus stories.)