ATLANTA (AP) _ The harsh Beijing flu is on the rise at the end of the flu season, meaning it's probably the strain that will dominate next winter.

''In nursing homes particularly, physicians need to be careful because ... this Type A flu hits the elderly very hard,'' Dr. Ali Khan of the Centers for Disease Control and Prevention said Thursday.

Although flu season generally winds down by mid-February, the bug's worst strain - Beijing flu, clinically known as Type A-H3N2 - began increasing last month, the CDC said.

Most flu cases this winter were the milder Type B, or Panama, flu, which affects mostly schoolchildren and young adults. From Sept. 27 through Jan. 16, Type A flu made up only 2 percent of flu cases, the CDC said.

But from Jan. 17 through Feb. 13, Type A flu made up 14 percent of cases, the CDC reported. Most were Beijing; a few others were another Type A strain, H1N1, which is somewhat milder than Beijing.

Type B flu still is the dominant strain this season, with cases in 43 states, the CDC said. Type A has been found in 29 states.

This has been a mild flu season, with hospitalizations and deaths remaining below expected rates, the CDC said. No exact figures were available.

The United States experienced a flu epidemic last winter, when Beijing flu began striking people two months before flu season was supposed to begin.

Flu seasons generally run in cycles, so doctors expect next year to be worse than this year. The strain that gains in strength near the end of flu season is generally the strain that dominates the following winter, so Beijing flu will be a chief ingredient in next winter's vaccine, the CDC said.

Meanwhile, Khan said nursing homes should provide prompt laboratory tests on flu patients to ensure accurate diagnosis of Type A flu, and then should administer amantadine. That antibiotic helps alleviate Type A symptoms.

Anyone with fever, cough and muscle aches in addition to cold symptoms should see a doctor, particularly if the illness improves but then returns, he said.

''A cold is an inconvenience whereas a flu can kill,'' quickly becoming pneumonia or causing bacterial infections, he said.

Flu generally kills about 10,000 Americans each year.