HIV Incidence in the United States

With Latest Data, CDC Warns that the “Epidemic Is Not Over”

Nov 2, 2009

There were more than 56,000 new HIV infections in the United States in 2006. Researchers have broken down the statistics to show which groups are most at risk.

Over one million people in the United States are living with HIV, according to the U.S. Centers for Disease Control (CDC). Approximately one in five don’t know they are infected.

Equally sobering, there were an estimated 56,300 new HIV infections in 2006, the latest year for which data are available. This total is based on a new, more accurate method of estimating the incidence rate (that is, the number of new HIV infections during a specific period). It is well above the CDC’s previous estimate of 40,000 new infections per year.

While gains have been made in testing, diagnosing, and treating HIV/AIDS in recent years, the CDC warns that “the epidemic is not over.” There were an estimated 14,561 AIDS deaths in the United States in 2007.

New Online Tool

The tool allows users to visualize the HIV incidence data by race/ethnicity and by transmission mode, and to combine those two categories. This information will be highly useful in planning for more effective prevention, testing, and treatment of HIV/AIDS.

HIV Incidence by Race/Ethnicity

African-Americans are the racial/ethnic group most severely affected by HIV and AIDS. They made up 12 percent of the population in 2006, but accounted for 45 percent of new HIV infections. The estimated incidence among blacks was seven times the estimated incidence among whites.

The second-ranking group was European-Americans, or whites, who accounted for 35 percent of new infections. Latinos accounted for 17 percent, slightly over their share of the population. Asian/Pacific Islanders and American Indian/Alaska Natives each accounted for less than 2 percent.

The CDC emphasizes that “race and ethnicity are not, by themselves, risk factors for HIV infection.” Instead, social, economic, behavioral, and medical factors may help explain the higher rates among African-Americans and Latinos. These factors include poverty, which limits access to high-quality health care; sexually transmitted diseases, which facilitate HIV transmission; and injection drug use, a well-documented HIV transmission route.

It is important to recognize that within each racial/ethnic group, different individuals have different behavioral risk factors for HIV. “The HIV epidemic cannot be viewed solely through the lens of race or ethnicity,” cautions the CDC.

HIV Incidence by Transmission Category

The overwhelming majority of new HIV infections in the United States take place through either sexual contact or injection drug use. Blood transfusion accounts for a tiny fraction of the total. Parent-to-child transmission is also rare in the United States, unlike in Africa, where millions of infants have acquired the virus from their mothers.

The U.S. epidemic remains heavily concentrated among men who have sex with men (MSM), who accounted for over half of new infections in 2006. This points to the continuing need to reach gay and bisexual men with prevention services.

Heterosexual transmission was the second-largest category, accounting for almost one-third of the total. The data show the high risk attached to heterosexual sex with an HIV-positive partner—a frequent route by which women become infected.

Injection drug use was the third-ranking category, accounting for 12 percent. And 4 percent of new cases were both injection drug users and MSM.

Combining Race and Transmission Data

Combining the statistics on racial/ethnic groups and transmission categories can reveal patterns that have important implications for prevention strategies.

MSM: Of the new infections caused by MSM, 46 percent were among whites, 35 percent among blacks, and 19 percent among Latinos. White men who have sex with men accounted for almost a quarter of all new HIV infections in 2006, more than any other group.

There were differences by age, however. Among black and Latino MSM, most new HIV infections occurred in young men, 13 - 29 years old. But among white MSM, most new infections occurred in men in their thirties.

Heterosexual transmission: African Americans accounted for 63 percent of new infections through heterosexual sex. Whites made up 20 percent, and Latinos 17 percent.

Among both blacks and whites, seven out of 10 people who acquired HIV through heterosexual contact were women. The CDC notes that African American women are “severely and disproportionately” affected by HIV. In 2006, the HIV diagnosis rate for black women was more than 19 times the rate for white women.

Injection drug use: Among people who acquired the virus by injecting drugs, 53 percent were black, 30 percent were white, and 17 percent were Latino. Males predominated in this group among African Americans and Latinos, but among whites the male-female split was about 50-50.

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The copyright of the article HIV Incidence in the United States in AIDS/HIV is owned by Cathy Sunshine. Permission to republish HIV Incidence in the United States in print or online must be granted by the author in writing.