The study captured a large sample of very poor MSM in Los Angeles, many of whom had experienced homelessness within the past year and had a history of incarceration. The estimated prevalence of HIV among Los Angeles MSM from behavioral surveillance is 19% (41
). The fact that 41% of the sexual episodes reported by HIV-positive participants were with partners who they believed to be HIV positive implies that as a group, HIV-positive MSM in our sample are engaging in seroconcordant partnerships more than would be expected by chance. Within these partnerships an increased odds of UAI was observed. Taken together, this suggests that many HIV-positive MSM in our sample are engaging in UAI within concordant partnerships. While this is indicative of serosorting as an intentional “risk management” strategy, several other possible explanations exist. For example, HIV-positive men may select HIV-positive partners for the sake of support and shared life experiences. Previous studies have shown that increased intimacy is associated with decreased condom use and by extension, increased UAI among MSM (42
). Our finding that seroconcordance was more common with main partnerships would seem to support the latter explanation. Regardless of the reason, the serosorting behaviors observed among HIV-positive MSM in our sample should theoretically reduce the risk of HIV transmission to uninfected partners. However, inferred partner HIV status is often incorrect (24
). If serosorting partnerships among HIV-positive men commonly involve both the highest frequency of sex (within main partnerships) and higher transmission risk behaviors, then risk of transmission would increase, even if unrecognized, in circumstances where HIV status of the partner is incorrectly identified. It is possible that increased risks of HIV transmission within main partnerships reported by other studies of MSM may in part be attributed to “failed” attempts at serosorting (44
Although only 4% of partnerships reported by HIV-negative participants were with HIV-positive partners, it is not clear that this avoidance of positive partners translates into serosorting among the HIV-negative MSM in our sample. Over half of the partners among HIV-negative participants were of an unknown HIV status, posing a substantial risk of infection. Additionally, increased odds of UAI with seroconcordant partners were not observed in univariate or multivariate models. As only 20 partnerships among HIV-negative men were with a HIV-positive partner, it is also possible that small cell sizes limited our ability to detect significant associations. For these reasons, evidence of serosorting among HIV-negative participants in our sample is not supported.
Substantial differences in sexual position by HIV status were noted within the sample. Interestingly, the percentage of participants reporting partnerships with UAI at last sex were similar between HIV-positive and negative men; 33% and 31% respectively. The type of UAI however, was different as more HIV-negative men reported UIAI and more HIV-positive men reported URAI, which is consistent with seropositioning as a risk management strategy. Differences in non-AI behaviors were observed as well and may indicate different strategies for HIV-positive and negative MSM who wish to avoid UAI.
When examining associations of partner HIV status on sexual position among a sub-sample of HIV-positive participants, a clear pattern of seroadaptation was observed. HIV-positive men had lower odds of UIAI and higher odds of URAI with partners of negative or unknown status compared to positive partners, indicating seropositioning. To our knowledge, there are no official recommendations that promote seropositioning as a risk management strategy for HIV-positive or HIV-negative men. Seroadaptation is often thought of as a “folk belief” based heavily on a 1999 Vittinghoff et al. paper among HIV-negative MSM, which estimated a lower per-contact risk of HIV seroincidence for engaging in UIAI with an HIV-positive or unkown partner compared to engaging in URAI with an HIV-positive or unkown partner (8
). It is unclear to what extent seroadaptation has been incorporated into mainstream HIV counseling and prevention approaches. Anecdotally, in many Los Angeles area HIV service organizations, seroadaptation is described to clients in terms of a “heirarchy of risk,” in which URAI is explained to pose a greater risk of acquiring HIV than UIAI. Similar to serosorting, no clear pattern of seropositioning was observed among the HIV-negative participants. Future studies should assess how participants are becoming informed about seroadaptation, delve into how these messages influence participants’ cognitions related to seroadaptation, and determine the level of awareness of newer studies showing mixed evidence for seroadaptaton as a “risk management” strategy.
The finding that 30% of HIV-positive men had oral-only sex and the fact that the odds of oral-only sex was higher with serodiscordant partners, although not statistically significant, suggests that oral sex may be a commonly used seroadaptive behavior among poor, HIV-positive MSM. Surprisingly, no association between discordant partners and condom use was observed. A recent qualitative study of HIV-positive minority MSM in Los Angeles noted a lack of availability of condoms in homeless shelters and incarcerated settings (46
). One-third (34%) of our sample reported their current housing situation as “a shelter, boarding house, or halfway house” or “a squat, abandoned building, on the street” and 53% said they had been homeless at some point in the past year. Structural barriers may prevent access to condoms and leave many individuals with few options other than seroadaptation to protect themselves from HIV infection, which provides some evidence of resilience in sexual decision making. Increased condom distribution, particularly in jails and areas with large populations of poor MSM, may be necessary to ensure adequate access among this population.
Studies of HIV risks in low-SES and homeless populations, especially youth, generally focus on non-main partners with whom sex is exchanged for food, money, shelter, or drugs (47
). While important, our findings suggest that among older marginalized MSM more attention needs to be paid to the role of main partnerships. In this study, only 4% of partnerships were identified as trade partners; 30% were considered main or regular partners (data not shown). The potential for “failed” serosorting in main partnerships, coupled with our findings of a negative association between main partnerships and oral-only sex among HIV-positive men and a positive association between main partners and unprotected versatile sex among HIV-negative men, underscores the need to better understand the role of main partnerships in HIV transmission of very low-SES MSM populations. This is especially so given the high HIV prevalence among MSM in Los Angeles and even higher prevalence in this sample, which is comprised of men who purportedly had sexual, social, and/or drug using ties between them.
These findings should be viewed in light of some limitations. As noted in previous studies using RDS, recruitment may not have reached the entire universe of the target population and therefore caution should be taken when generalizing results to younger or higher SES MSM (50
). Partner HIV status was based on the report of the index participant and a large proportion of partners’ HIV status was unknown. Moreover, the survey did not ask about seroadaptation directly; therefore, we do not know if the observed patterns are merely correlated or represent intentional “risk management” approaches. Caution should be taken when comparing the results between HIV-positive and HIV-negative men in this sample. The two groups differed substantially in terms of demographics, homelessness, substance use, and gender of sex partners (men-only vs. men and women). It is therefore possible that the differences in seroadaptive behaviors between HIV-positive and HIV-negative men in our sample can be attributed to factors other than their HIV status. For example, more HIV-negative men reported experiencing homelessness within the past year compared to HIV-positive men. If homelessness limits resiliency in sexual decision making, as we might expected given studies documenting relatively high rates of survival sex among the homeless (47
), then the lack of seroadaptation observed among HIV-negative men in the sample may be in part attributed to their increased exposure to homelessness.
This study provides evidence of seroadaptation among poor HIV-positive MSM in Los Angeles. Even in the face of abject poverty, HIV-positive MSM in our sample are attempting to mitigate the risk of transmission to others though a combination of seroadaptive behaviors, namely serosorting, oral-only sex, and seropositioning. This reflects an altruism that is especially noteworthy in a population with substantial un-met needs and several structural, social, and behavioral barriers to provision of their own health care (52
). Future studies should examine individuals’ cognitions related to seroadaptation, address the influence of partnerships, and determine the effect that structural factors play in encouraging seroadaptation as well as consistent condom use.