NEW YORK ( CNN ) -- New York City 's rate of HIV infection is about three times the national rate , according to estimates released Wednesday by the New York City Department of Health and Mental Hygiene . Rapid HIV test swabs incubate at the Iris House in New York in 2007 . The agency estimates that 72 of every 100,000 New Yorkers -- a total of 4,800 individuals -- contracted HIV in 2006 , more than triple the national rate of 23 per 100,000 . The findings are based on new lab technology and a newly derived statistical model developed by the Centers for Disease Control and Prevention . The lab technology enables health officials to determine whether HIV-positive individuals contracted the virus within the past five months , and the statistical model allows researchers to then make projections about a population 's infection rate . HIV , or the human immunodeficiency virus , is the virus that causes AIDS . The Health Department points to the city 's demographics . `` The populations that bear the greatest burden nationally -- blacks , for example , and men who have sex with men -- are highly represented in New York City , '' Health Commissioner Thomas Freidan said in a written statement . `` Because HIV is more prevalent within those groups , the risk of HIV infection per sexual contact is higher . '' In June , the city launched a three-year initiative to administer HIV tests to the 250,000 Bronx adults who have never been tested . The program was announced just days after release of a study finding a high rate of `` unsafe sexual behavior '' in the city . Freidan said the study showed that 36 percent of gay and bisexual New York men who had five or more partners in the previous year did not use condoms consistently . `` This is a core group which is at high risk for getting and spreading HIV , '' Freidan said . In July , a study of 452 men interviewed anonymously at gay bars and clubs found 39 percent of those having sex with other men had not revealed their sexual orientation to their doctors , significantly diminishing their likelihood of being tested for HIV .
Agency estimates 72 of every 100,000 New Yorkers contracted HIV in 2006 . Expert : Demographics of the city contribute to the high rate of HIV infection . The city launched a three-year initiative to give HIV tests to untested Bronx adults .