The American Medical Association (AMA) on Wednesday criticized the government's guidelines on quarantine and isolation in the United States, saying the guidance was "confusing" and risked further spread of COVID-19.

On Tuesday, the U.S. Centers for Disease Control and Prevention (CDC) stopped short of recommending a rapid antigen test for people seeking to end their COVID-19 isolation at five days.

"A negative test should be required for ending isolation after one tests positive for COVID-19. Re-emerging without knowing one's status unnecessarily risks further transmission of the virus," the AMA said.

The CDC last week reduced the recommended isolation period for people with asymptomatic COVID to five days from 10, and on Tuesday backed that decision saying a review of 113 studies from 17 countries showed that most transmission occurs early in the course of infection.

The AMA said physicians are concerned that these recommendations put patients at risk and could further overwhelm the healthcare system.

The omicron variant of the coronavirus has spread rapidly across the United States, leading to a surge in hospitalizations and a shortage of test kits.

The AMA urged the U.S. government to use all means to ramp up production and distribution of COVID-19 tests, adding that a "dearth of tests at the moment does not justify omitting a testing requirement to exit a now shortened isolation."