New data show New York City residents are contracting the virus that causes AIDS at three times the national rate.

The city health department said Wednesday that almost 4,800 New Yorkers were infected with HIV in 2006. That number represents 72 of every 100,000 residents, compared to a national rate of 23 per 100,000.

The figures pinpoint when people became infected with the virus, not just when they were diagnosed.

Health officials attribute the city's relatively high rate of new infections to its large populations of gay men, blacks and other groups on whom HIV has traditionally taken a heavy toll.

Assistant health commissioner Dr. Monica Sweeney says the figures underscore the continued need to promote HIV testing and prevention.