H.I.V. Is Spreading in New York City at Three Times the National Rate, a Study Finds

The virus that causes AIDS is spreading in New York City at three times the national rate — an incidence of 72 new infections for every 100,000 people, compared with 23 per 100,000 nationally — according to a study released on Wednesday by the city’s Department of Health and Mental Hygiene.


The findings, based on a new formula developed by the federal Centers for Disease Control and Prevention, estimated that 4,762 New Yorkers contracted H.I.V. in 2006, the most precise estimate the city had ever offered.

But the city stressed that because the method of estimating infections was new, it could not be said definitively whether the number of new infections in the city had increased or decreased from previous years.

Blacks, and men who have sex with other men, are the groups at greatest risk of contracting H.I.V., the study found. A summary of the new data:

¶Men accounted for 76 percent of new H.I.V. infections and women for 25 percent. (The figures exceed 100 percent because of rounding.)

¶Blacks made up 46 percent of the newly infected; Hispanics, 32 percent; and whites, 21 percent. (Figures for other racial or ethnic groups were not provided.)

¶Those under age 20 made up 4 percent of the newly infected; those 20 to 29 years old, 24 percent; those 30 to 39 years old, 29 percent; those 40 to 49 years old, 29 percent; and those 50 and older, 15 percent.

¶Sex between men was the main cause in 50 percent of new infections; high-risk heterosexual sex in 22 percent; intravenous drug use in 8 percent; and unknown or uncertain causes in 18 percent.

Manhattan accounted for 35 percent of new infections; Brooklyn, 26 percent; the Bronx, 19 percent; and Queens, 17 percent.

As the health department has repeatedly noted, gay minority men were particularly at risk. For example, of new H.I.V. infections among men under age 30 who have sex with men, 77 percent were in black or Hispanic men, as were 59 percent of new H.I.V. infections among men ages 30 to 50 who have sex with men.

Over all, the study found some interesting differences between national and local rates of new H.I.V. infections.

Nearly two-thirds of the city’s new infections occurred in people 30 to 50 years old. Nationally, people under 30 accounted for 41 percent of new infections, compared with 28 percent in New York City.

Also, within New York City, whites were infected at four times the national rate, Hispanics at three times the national rate, and blacks at almost twice the national rate.

The health department said in a news release:

“The analytic technique is new, and the estimates may be imprecise, but even a rough gauge of H.I.V. incidence is a valuable tool for understanding — and combating — the spread of H.I.V. The health department’s new estimate includes 2006 incidence figures for different age groups, racial groups and both genders. By repeating the exercise for subsequent years, researchers may be able to discern increases and decreases over time, and target their prevention efforts accordingly.”

Over the past year, the health department has warned that H.I.V. infections among young gay men have risen and that unsafe sex remains common.