Conference Coverage

Lifetime HIV infection risk declines, but some still at high risk


AT CROI 2016


BOSTON – The risk that a person living in the United States will become infected with HIV in his or her lifetime is declining compared with a decade ago, but the risk remains quite high among blacks and Hispanics/Latinos, investigators from the Centers for Disease Control and Prevention caution.

In fact, an estimated one in two black men who have sex with men (MSM) and one in four Hispanic/Latino MSM will be diagnosed with HIV within their lifetimes, reported CDC investigator Dr. Kristen Hess, at a media briefing and in an oral session at the 2016 Conference on Retroviruses and Opportunistic Infections.

Dr. Kristen Hess

Dr. Kristen Hess

“In the current analysis, we estimated that the overall lifetime risk is 1 in 99, which is reduced from 1 in 78 in the previous estimate [2004-2005]. However, there are vast disparities that still persist,” she said.

Estimates of lifetime risk are frequently used by epidemiologists to compare the burden of diseases such as cancer across populations, but are infrequently used for estimating lifetime risk of HIV infection, Dr. Hess said.

“The advantage to using lifetime risk is that it is more easily understood by the general population. Therefore, it could be a useful tool for clinicians, outreach workers, and policy makers,” she said in her podium presentation.

Previous estimates of lifetime HIV infection risk were based on data from 2004 and 2005, before data from all 50 states were available, leading the investigators to calculate new estimates based on more current information.

They drew on the National HIV Surveillance System for information about HIV diagnosis, mortality data from the National Center for Health Statistics, and U.S. Census data on population size by age, race/ethnicity, and state. The study covered the years 2009 through 2013.

The investigators used the number of HIV diagnoses and the number of non-HIV deaths to calculate the probability of a diagnosis of HIV at a given age and applied the probabilities to a hypothetical cohort to determine risk estimates.

They defined lifetime risk as” the cumulative probability of being diagnosed with HIV from birth.”

The lifetime risk of an HIV diagnosis for MSM varied widely by race/ethnicity. Overall, 1 in 64 men will be diagnosed with HIV during his lifetime, with the risk highest for black men at 1 in 20, followed by Hispanics at 1 in 48, native Hawaiian or other Pacific Islanders (NHOPI) at 1 in 82, American Indian/Alaskan Natives (AI/AN) at 1 in 129, whites at 1 in 132, and Asians with the lowest risk at 1 in 174.

For women the risks were considerably lower overall at 1 in 227. However, African American women had the same level of risk as Hispanic MSM (1 in 48). Risks for other racial/ethnic groups among women are: Hispanics, 1 in 227; NHOPI, 1 in 385; AI/AN, 1 in 399; whites, 1 in 880; and Asians, 1 in 883.

Lifetime risk from age 13 of an HIV diagnosis by risk group was highest among MSM, at 1 in 6, followed by female injectable drug users (1 in 23), male injectable drug users (1 in 36), heterosexual women (1 in 241), and heterosexual men (1 in 473).

Among MSM, the risk was highest for black men (1 in 2), followed by Hispanic/Latino (1 in 4), NHOPI (1 in 7), white (1 in 11), AI/AN (1 in 12) and Asians (1 in 14).

The overall lifetime risk of an HIV diagnosis among the U.S. population as a whole was 1 in 99. The area with the highest lifetime risk was Washington, D.C., with a risk of 1 in 13. Dr. Hess cautioned that the D.C. is a city, not a state, which could skew comparisons. The states with the highest lifetime HIV infection risk were Maryland, Georgia, and Florida, and in general, the highest lifetime risks were in the South.

The lowest overall risk was in North Dakota, at 1 in 670.

The investigators noted that their study was limited by its reliance on diagnosis rather than incidence data and may thus underestimate some risk categories because infection may occur several years before a diagnosis. Additionally, death certificates may be missing HIV information, she said.

“One of the goals of National HIV/AIDS strategy is to reduce disparities. Lifetime risk highlights work that still needs to be done and could be used to track progress toward this goal,” Dr. Hess said.

The study was supported by the CDC. Dr. Hess is a CDC employee.

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