Flu is rising rapidly across the U.S., driven by a new variant of the virus. The Centers for Disease Control and Prevention reported Tuesday that after a slow start to flu season in early December, much of the country is now seeing a jump in cases.

The state of New York is among those most heavily hit. For the week ending Dec. 20, the state reported its highest number of positive flu cases ever recorded in a single week, according to the New York State Department of Health. That represented an increase of 38% over the previous week, the department said.

Visits to health care providers were also up 6 percent this week for respiratory illness as the flu sweeps across the country.

The CDC estimates at least 7.2 million flu cases nationwide this season as of Dec. 20. Data shows that Michigan is seeing a "very high" influenza-like illness (ILI) activity level.

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That all followed a huge spike in flu activity in New York City, Long Island, and North Jersey in the first week of December. It has also been an early start — about a month early — for this year’s flu season, and infectious-disease experts warn that we haven’t hit the peak yet.

Flu cases have surged to an estimated 7.5 million nationwide while whooping cough (pertussis) cases approach 28,000 — a double threat as families prepare for New Year’s gatherings.

Local reporting and CDC maps indicate that flu and RSV infections are rising in Georgia, with doctors observing an uptick in cases as the winter respiratory season begins.