This meta-analysis provides the first quantitatively synthesized estimates of the prevalence of UAI with male sex partners among HIV-diagnosed MSM during the HAART era. The overall and stratified estimates are useful for targeted prevention efforts, for epidemiologic modeling of HIV transmission among MSM, and for providing parameters for resource allocation models.
We found that a sizeable percentage of HIV-diagnosed MSM had engaged in UAI with male partners. This is an important public health concern, given the high prevalence of HIV and STIs among MSM in the United States. There is also evidence, however, that some HIV-diagnosed MSM engage in behaviors that may lessen the probability of infecting others. First, UAI varied according to the perceived HIV status of male partners. The UAI prevalence was higher with HIV-seropositive partners than HIV-seronegative or serostatus unknown partners. Although we do not know the percentage of HIV-diagnosed MSM who engaged in UAI exclusively with HIV-seropositive partners, this serosorting pattern may be protective for new HIV transmissions. Conversely, it still leaves seropositive persons open to other STIs or possibly acquiring a drug-resistant strain of HIV [16,61]. Second, we also observed a pattern of strategic positioning [19,20] during UAI with serodiscordant partners. The risk of transmitting HIV is highest when HIV-seropositive MSM engage in insertive UAI with HIV-negative partners [21,22]. Our meta-analysis revealed that HIV-diagnosed MSM reported a higher prevalence of receptive UAI than insertive UAI with HIV-seronegative partners. This pattern of strategic positioning was also found when HIV-seropositive MSM were uncertain about the serostatus of their partners but not when partners were perceived to be HIV positive. The differences in the patterns of sexual behaviors with different serostatus partners support the contention of a previous study  that strategic positioning is an intentional and deliberate HIV-related harm-reduction practice rather than merely a reflection of sexual position preference. However, more research is needed on the extent to which MSM intentionally use strategic positioning and serosorting as harm-reduction strategies and the relative safety of those practices.
Our meta-analytic findings must be viewed within the context of the methodological limitations of the primary studies. Our findings are based on cross-sectional data, which provide snap shots of HIV-diagnosed MSM's behaviors at the time of data collection. Changes in transmission behaviors over time cannot be investigated using these data. However, some evidence from published cross-sectional data indicates that the prevalence of UAI with at-risk partners among the HIV-diagnosed MSM did not differ significantly by the length of time they had known they were HIV positive [11,62]; the prevalence of unprotected sex with at-risk partners (with a 3-month behavioral recall window) appeared to remain at a relatively stable level (20–30%) over 6–10 years after HIV diagnosis. Additional longitudinal data are needed to better describe behavioral trends in the years following an HIV diagnosis.
There is limited information from the original studies regarding how participants determined the serostatus of their male sex partner (based on either actual information received from a partner or a guess) and whether the participants had disclosed their own HIV-seropositive status to their sex partners. This has important implications for understanding whether serosorting and strategic positioning are effective harm-reduction strategies because both approaches rely on accurate assessment of partner's serostatus and mutual disclosure. Additionally, the number of unprotected sex acts and the number of sex partners were not included as outcomes in our meta-analysis because few studies provided the information. Future studies should collect and report the information to facilitate more precise estimates of HIV transmission.
The UAI prevalence was significantly lower in studies that used random or systematic sampling methods compared with studies that used convenience samples. Convenience samples might have selected more high-risk MSM; however, we did not find a significant difference in the UAI prevalence between the studies that required participants to be sexually active prior to assessment and the studies that did not have this requirement. A close examination suggests that the sampling method is highly correlated with the recruitment setting; seven of nine studies with random or systematic sampling methods were conducted in medical settings, which tended to have a lower prevalence of UAI. Further research is needed to untangle the complex relationship between level of risk, sampling methods, and recruitment settings.
Sexual behaviors were obtained with self-reports and thus open to recall and social desirability biases. The fact that the UAI prevalence was significantly higher in studies with self-administered questionnaires than in studies with interviewer-administered questionnaires suggests that HIV-seropositive MSM may have underreported socially undesirable behaviors when the questionnaire was administered by an interviewer. Thus, if any bias exists in the aggregated findings, it would be an underestimation of UAI prevalence.
Since the release of the Serostatus Approach to Fighting the HIV Epidemic in 2001, there has been an increased nationwide effort in promoting HIV testing, so that infected persons can become aware of their status [63,64]. With increases in the proportion of infected persons who become aware of their seropositive status, there will be a corresponding need for increases in prevention efforts targeting HIV-diagnosed persons. Evidence suggests that integrating prevention into settings in which HIV-diagnosed people receive medical care or other services and addressing an array of health, behavior, and well being issues are most likely to achieve success . Clinicians can reduce patients' risk for transmitting HIV to others by briefly discussing sexual behaviors, communicating prevention messages (protecting others and protecting one's health), identifying and treating STIs during clinic visits, and referring patients to more intensive risk reduction counseling and psychosocial services as needed [39,66,67]. The frequency with which HIV patients receive safer sex counseling from HIV medical providers has been significantly associated with decreased prevalence of UAI , but too many providers do not give this counseling [68,69]. In 2003, CDC, the Health Resources and Services Administration, National Institutes of Health, and the HIV Medicine Association of the Infectious Diseases Society of America developed evidence-based recommendations on incorporating HIV prevention into the medical care of persons living with HIV . As the recommendations become more widely adopted by medical providers nationwide, we may expect a larger reduction in HIV sexual behaviors among MSM who are in care.
Furthermore, prevention with positives programs in community settings that serve MSM (e.g., community-based organizations, pride events, and gay venues) continue to be needed for MSM in the United States, given a higher UAI prevalence in studies that recruited participants from community settings. A priority of these programs should be to address the safety of serosorting and strategic positioning. A concerted effort to establish and maintain these programs in medical as well as community settings is needed to reduce HIV transmission among MSM in the United States.
This work was supported by the Prevention Research Branch, Division of HIV/AIDS Prevention, U.S. CDC and was not funded by any other organization.
We sincerely thank the following authors for providing additional data to assist our coding and analyses: Angela Aidala; David S. Bimbi; Cherilyn R. Bingman; Michael Campsmith; Sanny Y. Chen; Shonda M. Craft; Paul Denning; Ralph DiClemente; Helen Ding; Theresa Exner; Ellen Funkhouser; Lytt Gardner; Christian Grov; Perry N. Halkitis; Ben Hadsock; David Holtgrave; Charlotte Kent; Andrea Y. Kim; Robert Klitzman; Gordon Mansergh; Gary Marks; Willi McFarland; Stephen Morin; Joanne Mullen; Dennis H. Osmond; David E. Ostrow; Jeffrey T. Parsons; Lance M. Pollack; Paul J. Poppen; Michael Reece; Jean L. Richardson; Starley Shade; Peter Theodore; Peter Vanable; Lance S. Weinhardt; William L. H. Whittington; Richard Wolitski. No compensation was received for any contributions made by these individuals.
N.C. had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. N.C., G.M., and R.J.W. conceptualized and designed the study. N.C., A.L., M.M.M., L.W.A., E.D.J., R.J.W., and G.M. did acquisition of data. N.C. and G.M. analyzed and interpreted the data and drafted the manuscript. N.C., G.M., R.J.W., A.L., M.M.M., L.W.A., K.J.M., and E.D.J. did critical revision of the manuscript for important intellectual content. N.C. provided statistical expertise. N.C., G.M., R.J.W., A.L., M.M.M., L.W.A., K.J.M., and E.D.J. provided administrative, technical, or material support.
The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the US CDC.
There are no conflicts of interest.
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