Age-Associated Trends in Diagnosis and Prevalence of Infection with HIV Among Men Who Have Sex with Men — United States, 2008–2016

In 2016, two thirds of diagnosed human immunodeficiency virus (HIV) infections in the United States were attributed to male-to-male sexual contact (1). The risk for sexual acquisition and transmission of HIV changes through the lifespan (2); to better guide prevention efforts for gay, bisexual, and other men who have sex with men (MSM*), CDC analyzed National HIV Surveillance System† (NHSS) data for MSM aged ≥13 years by age group (13-29, 30-49, and ≥50 years) in 50 states and the District of Columbia (DC). During 2008-2016, the annual number of diagnoses of HIV infection increased 3% per year among MSM aged 13-29 years, decreased 4% per year among those aged 30-49 years and was stable for MSM aged ≥50 years. The number of HIV diagnoses among MSM aged 13-29 years was four times that of MSM aged ≥50 years. During 2008-2015, the number of MSM aged ≥50 years living with diagnosed HIV infection (prevalence of HIV infection) increased an average of 11% per year and at year-end 2015 was three times that of MSM aged 13-29 years. Racial/ethnic disparities in HIV infection persisted, particularly among younger black/African American MSM who accounted for 49% of all diagnoses among MSM aged 13-29 years during 2008-2016. To avert the most infections and improve health outcomes (3), sexually active MSM at risk for HIV infection should be tested at least once a year, and, if positive, linked to and retained in HIV medical care to achieve viral suppression (4). Those testing negative should be provided HIV prevention services, including preexposure prophylaxis (PrEP) (5).

In 2016, two thirds of diagnosed human immunodeficiency virus (HIV) infections in the United States were attributed to male-to-male sexual contact (1). The risk for sexual acquisition and transmission of HIV changes through the lifespan (2); to better guide prevention efforts for gay, bisexual, and other men who have sex with men (MSM*), CDC analyzed National HIV Surveillance System † (NHSS) data for MSM aged ≥13 years by age group (13-29, 30-49, and ≥50 years) in 50 states and the District of Columbia (DC). During 2008-2016, the annual number of diagnoses of HIV infection increased 3% per year among MSM aged 13-29 years, decreased 4% per year among those aged 30-49 years and was stable for MSM aged ≥50 years. The number of HIV diagnoses among MSM aged 13-29 years was four times that of MSM aged ≥50 years. During 2008-2015, the number of MSM aged ≥50 years living with diagnosed HIV infection (prevalence of HIV infection) increased an average of 11% per year and at year-end 2015 was three times that of MSM aged 13-29 years. Racial/ethnic disparities in HIV infection persisted, particularly among younger black/African American MSM who accounted for 49% of all diagnoses among MSM aged 13-29 years during 2008-2016. To avert the most infections and improve health outcomes (3), sexually active MSM at risk for HIV infection should be tested at least once a year, and, if positive, linked to and retained in HIV medical care to achieve viral suppression (4). Those testing negative should be provided HIV prevention services, including preexposure prophylaxis (PrEP) (5).
All states and U.S. dependent areas report cases of HIV infection and associated patient demographic and clinical information to NHSS. CDC analyzed data reported through December 2017 from the U.S. states and DC, statistically adjusted for missing risk factor information (6), for MSM aged ≥13 years. Data were analyzed for MSM aged 13-29, 30-49, and ≥50 years.
Trends in annual diagnoses of HIV infection among MSM during 2008-2016 were measured using estimated annual percent change (APC) tabulated by age group and race/ethnicity and by age group and region of residence at diagnosis. The APC is calculated by using a generalized log linear model. Prevalence trends among MSM living with diagnosed HIV infection were measured using APCs tabulated by age group and last known jurisdiction of residence at year-end during 2008-2015. Changes were considered statistically significant if the APC's 95% confidence interval (CI) excluded zero.
Among 236,150 MSM with HIV infection diagnosed during 2008-2016, a total of 106,258 (45%) were aged 13-29 years, 100,857 (43%) were aged 30-49 years, and 29,034 (12%) were aged ≥50 years (Table 1). During this period, the annual number of diagnoses increased among MSM aged 13-29 years (APC = 2.9). The largest percentage increases in HIV diagnoses in this age group were among American Indians/Alaska Natives (APC = 14.8), Asians (12.0), and residents of the South (3.7). Among MSM aged 30-49 years, the annual number of diagnoses decreased (APC = -3.5). Among those aged ≥50 years, the overall trend was stable, although diagnoses increased among Asians (APC = 7.0) and Hispanics/Latinos (4. Racial/ethnic disparities in the occurrence of annual diagnoses of HIV infection persisted, particularly among younger MSM. Compared with non-Hispanic whites, blacks and Hispanics/Latinos accounted for a disproportionate number of cases. Among MSM aged 13-29 years, American Indians/ Alaska Natives, Asians, and residents of the South experienced the steepest increases in trends in annual diagnoses of HIV infection compared with other racial/ethnic groups and other U.S. regions; however, the numbers of annual diagnoses of HIV infection among American Indian/Alaska Native and Asian MSM were small. During 2008-2015, the number of MSM aged ≥50 years living with diagnosed HIV infection increased by 11% per year, and at year-end 2015, this group accounted for the largest age group of MSM living with diagnosed HIV infection, presumably as a result of increased survival associated with widespread use of antiretroviral therapy (7), surviving middle age, and advancing to the older group. In light of the large and increasing percentage of older MSM living with diagnosed HIV infection, care and treatment that includes achieving viral suppression and managing age-related comorbidities is essential (8).

Summary
What is already known about this topic?
In 2016, 67% of diagnosed human immunodeficiency virus (HIV) infections were attributed to male-to-male sexual contact.
What is added by this report?
During 2008-2016, the number of HIV diagnoses increased 3% annually among men who have sex with men (MSM) aged 13-29 years. The number of HIV diagnoses among MSM aged 13-29 years was four times that of MSM aged ≥50 years. Racial/ ethnic inequities in HIV persisted, particularly among younger black/African American and Hispanic/Latino MSM.
What are the implications for public health practice? MSM may be tested at least annually and, if positive, linked to and retained in HIV medical care. Those testing negative might benefit from prevention services, including preexposure prophylaxis. Strengthened efforts can reduce racial/ethnic inequities.
The increase in annual diagnosis of HIV infections among younger MSM might reflect increased HIV testing, in addition to ongoing transmission. Intensified efforts to increase the rate of HIV testing are particularly important for younger MSM because they account for the highest percentage of MSM with undiagnosed HIV infection (9). Increasing HIV testing can help diagnose HIV infection sooner, enable MSM to access HIV treatment (4), and reduce HIV transmission to others (10). To avert the largest number of infections and improve health outcomes, MSM should be tested at least once a year (3) and, if positive, linked to and retained in HIV medical care to achieve viral suppression (4). Those testing negative should receive HIV prevention services, including PrEP (5).
The findings in this report are subject to at least three limitations. First, some cases of HIV infection are reported to CDC without an identified risk factor. Statistical adjustments were applied for missing risk factor information (6); as a result of this imputation, estimated numbers of reported cases attributable to male-to-male sexual contact are higher than numbers of cases reported to CDC with male-to-male sexual contact indicated. Second, although NHSS data reflect high completeness of reporting from jurisdictions, § some diagnoses of HIV infection might not have been reported to CDC (resulting in an underestimation), and some might reflect duplicate reporting (resulting in an overestimation). These are mitigated by collecting all HIV-related laboratory and case information from providers of surveillance data and intrastate and interstate § CDC. Evaluation Framework. Oral presentation at the PS18-1802: Integrated HIV Surveillance and Prevention Programs for Health Departments: Recipient Orientation Meeting. Jun 6, 2018. Atlanta, Georgia.