The flu is now prevalent in New York, the state Health Department declared on Wednesday.

According to state data as of Dec. 14, a total of 23,313 positive flu cases across 60 counties in New York have been reported this season. In New York City, cases are up 72%, rising from 2,501 cases in the previous week to 4,300. For the rest of the state, week-over-week cases are up 75%. The state added hospitalizations due to influenza climbed by 48%.

The declaration by the DOH requires health care workers in health care and residential facilities and agencies regulated by the state DOH who are unvaccinated for flu to wear surgical or procedure masks.

"The flu vaccine is a safe and effective way to protect against infection and will lessen the symptoms if you get sick. I encourage everyone 6 months and older to get the flu shot, and it's not too late to protect yourself and your loved ones and ensure you don’t miss out on holiday celebrations,” state DOH Commissioner Dr. James McDonald said in a statement.