Washington, Dec 31 (IANS): The surge in Omicron cases is forcing the US National Institutes of Health (NIH) to postpone elective surgeries as a growing number of staff have been asked to isolate or quarantine, according to a memo.

The move came as at least 80 clinical centre staff called in sick on Wednesday alone because of Covid-19 infections or exposures, Xinhua news agency quoted a Reuters report on Thursday citing the memo as saying.

Staff of the largest hospital in the US devoted to clinical research were informed on Wednesday that elective surgeries would be delayed from next week, the report said.

A total of 250 new cases of Covid-19 were reported between December 20-27 out of an estimated 40,000 staff across all of NIH, it added.

This report comes after the Centers for Disease Control and Prevention (CDC) shortened isolation time for Americans infected with Covid-19 from 10 to five days.

In a new guideline released earlier this week, the US health agency is shortening the recommended time for isolation from 10 days for people with Covid-19 to five days, if asymptomatic, followed by five days of wearing a mask when around others.

The guidance does not require a negative test to leave isolation or quarantine, which experts worry may drive up transmission and new cases.