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Prevalence and Awareness of HIV Infection Among Men Who Have Sex With Men --- 21 Cities, United States, 2008

Men who have sex with men (MSM) are at increased risk for infection with human immunodeficiency virus (HIV). In 2006, 57% of new HIV infections in the United States occurred among MSM (1). To estimate and monitor risk behaviors, CDC's National HIV Behavioral Surveillance system (NHBS) collects data from metropolitan statistical areas (MSAs) using an anonymous cross-sectional interview of men at venues where MSM congregate, such as bars, clubs, and social organizations. This report summarizes NHBS data from 2008, which indicated that, of 8,153 MSM interviewed and tested in the 21 MSAs participating in NHBS that year, HIV prevalence was 19%, with non-Hispanic blacks having the highest prevalence (28%), followed by Hispanics (18%), non-Hispanic whites (16%), and persons who were multiracial or of other race (17%). Of those who were infected, 44% were unaware of their infection. Men who know their current HIV infection status can be linked to appropriate medical care and prevention services. Once linked to prevention services, men can learn ways to avoid transmitting the virus to others. Young MSM (aged 18--29 years) (63%) and minority MSM (other than non-Hispanic white) (54%) were more likely to be unaware of their HIV infection. Efforts to ensure at least annual HIV testing for MSM should be strengthened, and HIV testing and prevention programs should increase their efforts to reach young and minority MSM.

NHBS is a behavioral surveillance system used to monitor prevalence and trends in 1) HIV-related risk behaviors, 2) HIV testing, and 3) use of HIV prevention services among populations at high risk for acquiring HIV, including MSM, injection-drug users, and heterosexuals at increased risk for HIV infection. Data are collected in annual cycles from one risk group per year so that each group is surveyed once every 3 years. The first cycle of NHBS (among MSM) was conducted in 15 MSAs during 2004--2005; behavioral surveys were conducted in 10 MSAs, and HIV testing in conjunction with the behavioral survey was conducted in five MSAs (2). In 2008, NHBS staff members in 21 MSAs collected cross-sectional behavioral risk data and conducted HIV testing among MSM. MSAs were selected based on high prevalence of acquired immunodeficiency syndrome (AIDS); the 21 MSAs included approximately 60% of all prevalent urban U.S. AIDS cases in 2006. MSM were sampled using venue-based, time-space sampling methods. Health department staff members first identified appropriate venues (e.g., bars, clubs, organizations, and street locations) and days and times when men frequented those venues (3). Venues and the corresponding day/time periods (VDTs) were chosen randomly each month. Staff members then systematically approached men at the venues (2). Men eligible for being interviewed were aged ≥18 years, residents of the MSAs, and able to complete the interview in English or Spanish. After participants gave informed consent, trained interviewers administered a standardized, anonymous questionnaire using a handheld computer. The interview consisted of questions about sex, drug use, HIV testing behaviors, and use of HIV prevention services. All respondents were offered anonymous HIV testing, regardless of self-reported HIV infection status, given the opportunity to receive their test results, and anonymously referred to care when appropriate. HIV testing was performed by collecting blood or oral specimens for either Western blot (WB) or immunofluorescence assay (IFA) confirmatory testing in a laboratory or rapid testing at venues using Food and Drug Administration (FDA)--approved tests for use in nonlaboratory settings. A nonreactive rapid test was considered a definitive negative result; reactive (preliminary positive) rapid test results were considered definitive positive only when confirmed by WB or IFA. MSM unaware of their HIV infection were defined as those who tested HIV-positive at the time of the interview but reported that the result of their most recent HIV test was negative, indeterminate, or unknown, or that they had never been tested. Men were compensated both for their time participating in the interview and for taking an HIV test.

In 2008, a total of 28,468 men were approached, and 12,325 were screened for participation in NHBS at 626 venues in 21 MSAs. Of men who were screened, 11,074 (90%) were eligible for the survey. Men were excluded from analysis if they did not consent to and complete both the survey and the HIV test (n = 1,558), did not report sex with a man during the preceding 12 months (n = 1,744), had an indeterminate HIV test result (n = 85), or reported being HIV-positive but had a negative NHBS HIV test result (n = 60). These criteria were not mutually exclusive; a total of 2,921 men were excluded from analysis. Of eligible men, 8,153 (74%) were MSM who met criteria for inclusion in this analysis. The median age of the MSM in this report was 32 years (range: 18--85 years); 44% were non-Hispanic white, 25% Hispanic, 23% non-Hispanic black, 2% Asian, 0.8% Native Hawaiian/Pacific Islander, 0.6% American Indian/Alaska Native, and 4% multiracial or other. Thirty-seven percent had a college education or higher, and 30% reported an annual household income <$20,000. Sixty-seven percent of men reported a household size of one. The majority had health insurance (66%) and had visited a health-care provider during the preceding year (76%) (Table 1).

Among the 8,153 MSM tested, 1,562 (19%) tested positive for HIV (range by MSA: 6%--38%). HIV prevalence was 28% among blacks, 18% among Hispanics, and 16% among whites. HIV prevalence increased with increasing age and decreased with increasing education and income (Table 1).

Of the 1,562 HIV-infected MSM, 680 (44%) were unaware of their infection. The proportion who were unaware of their infection was higher among younger than older MSM (Table 1). The proportion unaware was highest among blacks (59%), lowest among whites (26%), and decreased with increasing education and income. Higher proportions of MSM with no health insurance and those who had not visited a health-care provider during the preceding year were unaware of their infection (Table 1). Fifty-five percent of MSM unaware of their infection had not been tested during the preceding 12 months.

The HIV prevalence by age group and race/ethnicity for MSM aged <30 years was highest among black MSM in each age group. The majority of young black and Hispanic MSM in each age group were unaware of their HIV infection (Table 2).

For comparison with a previous NHBS report of MSM HIV prevalence during 2004--2005, which indicated an HIV prevalence of 26% among MSM and an infection unawareness rate of 48% (4), five MSAs (Baltimore, Maryland; Los Angeles, California; Miami, Florida; New York, New York; and San Francisco, California) were analyzed separately in the analysis of 2008 data. Results indicated that the overall HIV prevalence was 27%, and 48% of HIV-positive participants were unaware of their infection. HIV prevalence among blacks was 40%; 63% were unaware of their infection. These prevalence rates were similar to those from 2004--2005 NHBS data*; the proportion of MSM unaware of their infection did not increase (Table 3).

Reported by

A Smith, MPH, I Miles, ScD, B Le, MD, T Finlayson, PhD, A Oster, MD, E DiNenno, PhD, Div of HIV/AIDS Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, CDC.

Editorial Note

The findings from this analysis corroborate other surveillance data showing that HIV prevalence among MSM remains high, many HIV-infected MSM are unaware that they are infected with HIV, and minority MSM are disproportionately affected by HIV (5--6). Because MSM represent the only group with increasing HIV incidence and comprise the largest proportion of new infections (1), it is critical to target resources and prevention strategies to MSM. The National HIV/AIDS Strategy§ emphasizes the importance of improving the impact of HIV prevention efforts for MSM. The NHBS data also underscore the specific need for increased HIV testing efforts for all MSM, especially minority MSM; CDC recently broadened its expanded HIV testing initiative to reach more MSM.

CDC currently recommends that sexually active MSM get tested for HIV at least once per year (7). NHBS data demonstrate that 55% of MSM who were unaware of their HIV infection had not had an HIV test during the preceding 12 months. This finding suggests that increased efforts to educate MSM and health-care providers about HIV testing guidelines and to reduce barriers to HIV testing for MSM are necessary. Also, because 45% of MSM who were unaware of their infection were tested within the previous 12 months, shorter intervals for testing some MSM might be warranted and should be considered in future recommendations.

This analysis shows racial and economic disparities in both HIV prevalence and awareness of HIV infection. Racial disparities were observed in the youngest age group (18--19 years) and increased with age. CDC is working to decrease these racial disparities and currently funds HIV prevention programs for young, minority MSM.** The economic disparities described in this report are consistent with those reported among heterosexuals participating in NHBS.†† This reinforces the need for targeting prevention efforts to low-income populations, which might reduce HIV infection rates among MSM.

The findings in this report are subject to at least four limitations. First, because the survey was administered by an interviewer, positive HIV status might have been underreported during the interview, given the sensitive nature of the topic, thereby inflating estimates of MSM unaware of their infections. Second, 135 MSM who reported being HIV-positive but who had a negative or indeterminate HIV test result were excluded from analysis because of the possibility that they had false-negative NHBS test results; however, including these men as HIV-positive would have yielded a similar overall HIV prevalence (20% compared with 19%). Third, comparisons of the NHBS-MSM datasets collected during 2004--2005 and 2008 should be made cautiously, because this analysis did not control for demographic differences in the samples, which might have influenced the percentages reported. Finally, these findings are limited to men who frequented MSM-identified venues (most of which were bars [45%] and dance clubs [22%]) during the survey period in 21 MSAs with high AIDS prevalence; the results are not representative of all MSM. A lower HIV prevalence (11.8%) has been reported among MSM in the general U.S. population (8).

The high proportion of MSM unaware of their HIV infection continues to be a serious public health concern, because these MSM account for the majority of estimated new HIV transmissions in the United States (9). Persons aware of their HIV infection often take substantial steps to reduce their risk behaviors, which could reduce HIV transmission (10). Whereas many MSM described in this report had not received an HIV test during the preceding 12 months, 45% of MSM who were unaware of their infection did report having an HIV test during the preceding 12 months, indicating they had acquired HIV recently or reported an incorrect HIV test result to the interviewer.

NHBS provides important information to guide and monitor HIV prevention efforts nationally and locally and will be critical for monitoring the impact of the National HIV/AIDS Strategy. The 2008 NHBS data show that MSM remain a key target of strategies to reduce HIV incidence and decrease racial and socioeconomic disparities in the United States.

Acknowledgments

This report is based, in part, on contributions by National HIV Behavioral Surveillance system staff members, including J Taussig, R Gern, T Hoyte, L Salazar, B Hadsock, Atlanta, Georgia; C Flynn, F Sifakis, Baltimore, Maryland; D Isenberg, M Driscoll, E Hurwitz, Boston, Massachusetts; N Prachand, N Benbow, Chicago, Illinois; S Melville, R Yeager, A Sayegh, J Dyer, A Novoa, Dallas, Texas; M Thrun, A Al-Tayyib, R Wilmoth, Denver, Colorado; E Higgins, V Griffin, E Mokotoff, Detroit, Michigan; M Wolverton, J Risser, H Rehman, Houston, Texas; T Bingham, E Sey, Los Angeles, California; M LaLota, L Metsch, D Beck, D Forrest, G Cardenas, Miami, Florida; C Nemeth, C-A Watson, Nassau-Suffolk, New York; WT Robinson, D Gruber, New Orleans, Louisiana; C Murrill, A Neaigus, S Jenness, H Hagan, T Wendel, New York, New York; H Cross, B Bolden, S D'Errico, Newark, New Jersey; K Brady, A Kirkland, Philadelphia, Pennsylvania; V Miguelino, A Velasco, San Diego, California; H Raymond, W McFarland, San Francisco, California; SM De León, Y Rolón-Colón, San Juan, Puerto Rico; M Courogen, H Thiede, N Snyder, R Burt, Seattle, Washington; M Herbert, Y Friedberg, D Wrigley, J Fisher, St. Louis, Missouri; and P Cunningham, M Sansone, T West-Ojo, M Magnus, I Kuo, District of Columbia.

References

  1. Hall HI, Song R, Rhodes P, et al. Estimation of HIV incidence in the United States. JAMA 2008;300:520--9.
  2. MacKellar DA, Gallagher K, Finlayson T, Sanchez T, Lansky A, Sullivan P. Surveillance of HIV risk and prevention behaviors of men who have sex with men---a national application of venue-based, time-space sampling. Public Health Rep 2007;122:39--47.
  3. Allen D, Finlayson T, Abdul-Quader A, Lansky A. The role of formative research in the National HIV Behavioral Surveillance System. Public Health Rep 2009;124:26--33.
  4. CDC. HIV prevalence, unrecognized infection, and HIV testing among men who have sex with men---five U.S. cities, June 2004--April 2005. MMWR 2005;54:597--601.
  5. Campsmith M, Rhodes P, Hall I, Green T. Undiagnosed HIV prevalence among adult and adolescents in the United States at the end of 2006. J Acquir Immune Defic Syndr 2010;53:619--24.
  6. CDC. Cases of HIV infection and AIDS in the United States and dependent areas, 2007. HIV/AIDS Surveillance Report 2009;19.
  7. CDC. Revised recommendations for HIV testing of adults, adolescents, and pregnant women in health-care settings. MMWR 2006;55(No. RR-14).
  8. Fujie X, Sternberg M, Markowitz L. Men who have sex with men in the United States: demographic and behavioral characteristics and prevalence of HIV and HSV-2 infection. Sex Transm Dis 2010;37:399--405.
  9. Marks G, Crepaz N, Janssen RS. Estimating sexual transmission of HIV from persons aware and unaware that they are infected with the virus in the USA. AIDS 2006;20:1447--50.
  10. Marks G, Crepaz N, Senterfitt JW, et al. Meta-analysis of high-risk sexual behavior in persons aware and unaware they are infected with HIV in the United States: implications for HIV prevention programs. J Acquir Immune Defic Syndr 2005;39:446--53.

* In New York, HIV prevalence rose between the two periods, but this was primarily caused by an increase in the proportion of participants who were black, Hispanic, or aged ≥40 years.

Original report was based on preliminary data. Percentages in this report reflect unpublished analyses of final data.

§ Additional information available at http://www.whitehouse.gov/administration/eop/onap.

Additional information available at http://www.cdc.gov/hiv/topics/funding/ps10-10138/index.htm.

** Additional information available at http://www.cdcnpin.org/scripts/display/funddisplay.asp?fundnbr=3582.

†† Socioeconomic disparities in HIV rates also have been reported in NHBS among the heterosexual population (Abstract no. WEPPD101, International AIDS Conference, July 2010).


What is already known on this topic?

The greatest number of human immunodeficiency virus (HIV) infections in the United States occur among men who have sex with men (MSM).

What is added by this report?

Data from a convenience sample of MSM in 21 U.S. cities indicated an HIV prevalence of 19% in 2008; 44% of HIV-infected MSM were unaware of their HIV infection, and the highest HIV prevalence and infection unawareness were among young and minority MSM. More than half (55%) of MSM unaware of their infection reported not having an HIV test during the preceding 12 months.

What are the implications for public health practice?

Increased efforts to educate MSM and health-care providers about HIV testing guidelines and to reduce barriers to HIV testing for MSM are necessary; MSM remain a key target for HIV testing and prevention programs.


TABLE 1. Prevalence of human immunodeficiency virus (HIV) infection and proportion unaware of HIV infection among men who have sex with men, by selected characteristics --- National HIV Behavioral Surveillance System, 21 U.S. cities, 2008

Characteristic

Total no. tested

HIV prevalence

Unaware of HIV Infection

No.

(%)

(95% CI*)

No.

(%)

(95% CI)

Age group (yrs)

18--19

423

28

(7)

(4--9)

21

(75)

(55--89)

20--24

1,466

170

(12)

(10--13)

115

(68)

(61--75)

25--29

1,529

223

(15)

(13--17)

128

(57)

(51--64)

30--39

2,231

470

(21)

(19--23)

214

(46)

(41--50)

40--49

1,712

474

(28)

(26--30)

164

(35)

(30--39)

≥50

792

197

(25)

(22--28)

38

(19)

(14--26)

Race/Ethnicity

American Indian/Alaska Native

45

8

(18)

(8--32)

---§

---§

---§

Asian

185

14

(8)

(4--12)

6

(43)

(18--71)

Black, non-Hispanic

1,895

539

(28)

(26--31)

318

(59)

(55--63)

Hispanic

2,045

358

(18)

(16--19)

163

(46)

(40--51)

Native Hawaiian/Pacific Islander

62

11

(18)

(9--30)

5

(45)

(17--77)

White, non-Hispanic

3,580

560

(16)

(15--17)

143

(26)

(22--29)

Other

336

72

(21)

(17--26)

42

(58)

(46--70)

Education

Less than high school diploma

526

132

(25)

(21--29)

68

(52)

(43--60)

High school diploma or equivalent

1,904

446

(23)

(22--25)

236

(53)

(48--58)

Some college or technical college

2,714

565

(21)

(19--22)

230

(41)

(37--45)

College or higher education

3,009

419

(14)

(13--15)

146

(35)

(30--40)

Annual household income

≤$19,999

2,416

639

(26)

(25--28)

305

(48)

(44--52)

$20,000--$39,999

2,084

391

(19)

(16--20)

182

(47)

(42--52)

$40,000--$74,999

1,986

302

(15)

(14--17)

117

(39)

(33--45)

≥$75,000

1,557

213

(14)

(12--16)

64

(30)

(24--37)

Sexual identity

Heterosexual

96

8

(8)

(4--16)

5

(63)

(25--92)

Bisexual

1,485

273

(18)

(16--20)

173

(63)

(57--69)

Homosexual

6,562

1,279

(19)

(19--21)

501

(39)

(37--42)

Health insurance

No

2,722

513

(19)

(17--20)

290

(57)

(52--61)

Yes

5,305

1,019

(19)

(18--20)

379

(37)

(34--40)

Visited health-care provider in past year

No

1,940

228

(12)

(10--13)

185

(81)

(75--86)

Yes

6,210

1,334

(21)

(21--23)

495

(37)

(35--40)

Most recent HIV test

Never

745

106

(14)

(12--17)

106

(100)

(97--100)

>12 months ago

2,632

843

(32)

(30--34)

262

(31)

(28--34)

≤12 months ago

4,752

605

(13)

(12--14)

306

(51)

(47--55)

Metropolitan statistical area

Atlanta, Georgia

343

22

(6)

(4--10)

12

(55)

(32--76)

Baltimore, Maryland

447

169

(38)

(33--43)

124

(73)

(66--80)

Boston, Massachusetts

198

24

(12)

(8--18)

7

(29)

(13--51)

Chicago, Illinois

516

93

(18)

(15--22)

49

(53)

(42--63)

Dallas, Texas

461

119

(26)

(22--30)

64

(54)

(44--63)

Denver, Colorado

449

70

(16)

(12--19)

14

(20)

(11--31)

Detroit, Michigan

312

44

(14)

(10--19)

31

(70)

(55--83)

Houston, Texas

436

113

(26)

(22--30)

26

(23)

(16--32)

Los Angeles, California

478

89

(19)

(15--22)

29

(33)

(23--43)

Miami, Florida

526

133

(25)

(22--29)

60

(45)

(37--54)

Nassau-Suffolk, New York

242

19

(8)

(5--12)

5

(26)

(9--51)

New Orleans, Louisiana

354

76

(21)

(17--26)

20

(26)

(17--38)

New York, New York

462

132

(29)

(25--33)

69

(52)

(43--61)

Newark, New Jersey

80

15

(19)

(11--29)

---§

---§

---§

Philadelphia, Pennsylvania

440

48

(11)

(8--14)

34

(71)

(56--83)

San Diego, California

490

87

(18)

(15--21)

35

(40)

(30--51)

San Francisco, California

474

111

(23)

(20--28)

21

(19)

(12--28)

San Juan, Puerto Rico

313

36

(12)

(8--16)

26

(72)

(55--86)

Saint Louis, Missouri

306

42

(14)

(10--18)

14

(33)

(20--50)

Seattle, Washington

352

52

(15)

(11--19)

8

(15)

(7--28)

Washington, DC

474

68

(14)

(11--18)

28

(41)

(29--54)

Total

8,153

1,562

(19)

(18--20)

680

(44)

(41--46)

* Confidence interval. Calculated using the Clopper-Pearson method.

Numbers might not add to total because of missing data.

§ Suppressed because of small cell size (fewer than five).

Includes persons who indicated multiple races or other race.


TABLE 2. Prevalence of human immunodeficiency virus (HIV) infection and proportion unaware of HIV infection among young men who have sex with men, by age group and race/ethnicity --- National HIV Behavioral Surveillance System, 21 U.S. cities, 2008

Characteristic

Total no. tested

HIV prevalence

Unaware of HIV Infection

No.

(%)

(95% CI*)

No.

(%)

(95% CI)

18--19 yrs

Black, non-Hispanic

193

17

(9)

(5--14)

12

(71)

(44--90)

Hispanic

137

5

(4)

(1--8)

4

(80)

(28--100)

White, non-Hispanic

63

---

---

---

---

---

---

20--24 yrs

Black, non-Hispanic

482

95

(20)

(16--24)

66

(69)

(59--79)

Hispanic

415

33

(8)

(6--11)

24

(73)

(55--87)

White, non-Hispanic

440

29

(7)

(5--9)

16

(55)

(36--74)

25--29 yrs

Black, non-Hispanic

346

105

(30)

(26--36)

76

(72)

(63--81)

Hispanic

412

50

(12)

(9--16)

27

(54)

(39--68)

White, non-Hispanic

607

46

(8)

(6--10)

14

(30)

(18--46)

Total

3,098

382

(12)

(11--14)

241

(63)

(58--68)

* Confidence interval. Calculated using the Clopper-Pearson method.

Suppressed because of small cell size (fewer than five).


TABLE 3. Prevalence of human immunodeficiency virus (HIV) infection and proportion unaware of HIV infection among men who have sex with men, by age group and race/ethnicity --- National HIV Behavioral Surveillance System, five U.S. cities, June 2004--April 2005 and 2008

Characteristic

June 2004--April 2005

2008

Total no. tested

HIV prevalence

Unaware of HIV Infection

Total no. tested

HIV prevalence

Unaware of HIV Infection

No.

(%)

(95% CI*)

No.

(%)

(95% CI)

No.

(%)

(95% CI)

No.

(%)

(95% CI)

Age group (yrs)

18--19

85

12

(14)

(8--23)

9

(75)

(43--95)

119

13

(11)

(6--18)

9

(69)

(39--91)

20--24

327

48

(15)

(11--19)

39

(81)

(67--91)

406

63

(16)

(12--19)

53

(84)

(73--92)

25--29

306

53

(17)

(13--22)

38

(72)

(58--83)

432

87

(20)

(17--24)

57

(66)

(55--75)

30--39

589

172

(29)

(26--33)

84

(49)

(41--57)

676

192

(28)

(25--32)

93

(48)

(41--56)

40--49

360

138

(38)

(33--44)

39

(28)

(21--37)

521

185

(36)

(31--40)

69

(37)

(30--45)

≥50

99

30

(30)

(22--40)

9

(30)

(15--49)

233

94

(40)

(34--47)

22

(23)

(15--33)

Race/Ethnicity

Black, non-Hispanic

441

203

(46)

(41--51)

136

(67)

(60--73)

625

252

(40)

(36--44)

160

(63)

(57--69)

Hispanic

464

82

(18)

(14--22)

41

(50)

(39--61)

846

195

(23)

(20--26)

87

(45)

(38--52)

White, non-Hispanic

616

126

(21)

(17--24)

23

(18)

(12--26)

708

142

(20)

(17--23)

27

(19)

(13--26)

Other§

229

39

(17)

(12--23)

18

(46)

(30--63)

206

45

(22)

(16--28)

29

(64)

(49--78)

Metropolitan statistical area

Baltimore, Maryland

468

182

(39)

(34--44)

112

(62)

(54--69)

447

169

(38)

(33--43)

124

(73)

(66--80)

Los Angeles, California

376

73

(19)

(16--24)

31

(43)

(31--55)

478

89

(19)

(15--22)

29

(33)

(23--43)

Miami, Florida

225

49

(22)

(17--28)

24

(49)

(34--64)

526

133

(25)

(22--29)

60

(45)

(37--54)

New York, New York

336

62

(19)

(14--23)

32

(52)

(39--65)

462

132

(29)

(25--33)

69

(52)

(43--61)

San Francisco, California

361

87

(24)

(20--29)

19

(22)

(14--32)

474

111

(23)

(20--28)

21

(19)

(12--28)

Total

1,766

453

(26)

(24--28)

218

(48)

(43--53)

2,387

634

(27)

(25--28)

303

(48)

(44--52)

* Confidence interval. Calculated using the Clopper-Pearson method.

Numbers might not add to total because of missing data.

§ Because of small sample sizes, category includes American Indian/Alaska Native, Asian, Native Hawaiian/Pacific Islander, and persons who indicated multiple races or other race.



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