The number of people living with HIV is growing as more patients survive thanks to antiretroviral drugs, the US Centers for Disease Control and Prevention revealed on Thursday in a report published in its journal Morbidity and Mortality Weekly Report.

To be more specific, the HIV-infected population rose to 1.1 million in 2006 from an estimated 994,000 in 2003, meaning that since 2003, HIV prevalence has increased by 11 percent, or 112,000 people. The estimate is somewhat similar to another report released this time by UNAIDS, the United Nations agency that tracks the disease worldwide, which said that an estimated 1.2 million people were living with HIV in the US.

CDC expects HIV cases “to keep on increasing over time as treatment prolongs the lives of infected people and new infections outpace deaths,” Richard Wolitski, acting director of CDC’s Division of HIV/AIDS Prevention, said.

Since 1996 when retroviral drugs were introduced, the average life expectancy of 20-year-old HIV patients has risen about 13 years, a study in the journal Lancet said in July.

The CDC previously reported that more people are becoming infected each year than previously estimated, with 56,300 new HIV infections in the US in 2006. Previous estimates put the number of new infections at about 40,000 a year.

The new report supports previous data released by the CDC referring to infection rate among blacks and gay men. Blacks account for about 46 percent of cases in 2006. About 1.7 percent of U.S. blacks are infected, compared with 0.6 percent of Hispanics and 0.2 percent of whites. Referring to gay men, they represented 48 percent of those living with HIV.

Other findings reveal that 28 percent of Americans living with HIV are heterosexual, 72 of American women with HIV and 13 percent of American men with HIV were infected via heterosexual intercourse and 19 percent of Americans living with HIV were infected via injection drug use.

The number of people not knowing they’re infected with HIV is decreasing, from 25 percent in 2003 to 21 percent in 2006, due to both increased diagnoses and a decline in deaths among persons living with HIV, the report showed. Despite the decrease though, more than one in five people living with HIV – 232,700 Americans – have no idea they’re carrying the AIDS virus. This leads to another sad statistic: 38 percent of Americans learn they have HIV only within a year of developing AIDS. HIV treatment is most effective when the disease is diagnosed soon after infection.

Therefore, “we need to have strong prevention programs so we can prevent these infections from occurring in the first place,” Wolitski said.

Since 1981, when AIDS first came to public notice, the disease has killed at least 25 million people, and 33 million others are living with the disease or HIV.