HIV serosorting as a harm reduction strategy: Evidence from Seattle, Washington

Center for Studies in Demography and Ecology, Box 353412, University of Washington, Seattle, WA 98195, USA.
AIDS (London, England) (Impact Factor: 5.55). 11/2009; 23(18):2497-506. DOI: 10.1097/QAD.0b013e328330ed8a
Source: PubMed


We sought to estimate how serosorting may affect HIV prevalence and individual risk among men who have sex with men in Seattle, Washington, and how the results vary under different assumptions of HIV testing frequency, heterogeneity in sexual behavior, and condom use.
We developed a deterministic mathematical model of HIV transmission dynamics. Data from the 2003 random digit dial study of men who have sex with men conducted in Seattle, Washington (n = 400) are used to parameterize the model.
Predicted population-level HIV prevalence as well as an individual's risk of HIV acquisition decreases when the odds of serosorting are increased in the mathematical model. In our model based on observed levels of serosorting, we predict an HIV prevalence of 16%. In contrast, if serosorting were eliminated in the population, we predict that HIV prevalence would increase to 24.5%. However, our findings depend on rates of condom use, mean anal sex contact rates, and HIV testing in the population.
Under realistic scenarios of sexual behavior and testing frequency for men who have sex with men in the United States, serosorting can be an effective harm reduction strategy.

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Available from: Susan Cassels, Mar 19, 2014
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    • "The practice of serosorting, which is defined as having sex without condoms exclusively or preferentially with partners of concordant HIV status and of using condoms with HIV-discordant or HIV status unknown partners, has become increasingly common among MSM [12,14,36,37]. Research has shown that this practice can increase the risk of acquiring HIV and other STIs [13,14,36,38,39], whereas others have found that this practice might decrease risk of infection [11]. Whether serosorting might or might not work as a risk management strategy is influenced by various factors, such as the prevalence of HIV in the population; the explicitness of communication; the proportion of people living with HIV who are aware of being infected; the incidence of new HIV infection among people previously testing negative for HIV and practicing HIV serosorting, and their position in sexual networks; the willingness to disclose HIV infection to a potential sex partner; the context of serostatus communication; and the proportion of people living with HIV under effective ART [14,37]. "
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    ABSTRACT: Background Data on knowledge, attitudes, behaviour and practices (KABP) of persons with recent HIV infection compared to controls with negative HIV test result provide information on current risk patterns and can help to re-focus HIV prevention strategies. Methods From March 2008 through May 2010, persons newly diagnosed with HIV (cases) and HIV-negative controls were recruited by physicians in Germany. To distinguish recent (< 5 months) from longstanding (> 5 months) infection, dried blood spots from people newly diagnosed with HIV were tested with the BED IgG-capture ELISA. Cases and controls completed a KABP-questionnaire. We compared cases with recent infection and controls among men having sex with men (MSM) regarding reported risk behaviour in the previous 6 months. To detect differences, unadjusted Odds Ratios (OR) were calculated and multivariate analysis was performed. Results Cases and controls did not differ in terms of knowledge on transmission risks, HIV testing frequency, partnership status, or regarding the frequency of any unprotected sex with partners known to be HIV-positive or assumed to be HIV-negative. Cases more often reported a shorter duration of partnership (< 6 months) with a primary partner than controls (OR = 3.9; p = 0.003) and indicated lower rates of condom use outside of primary relationships, with acquaintances (OR = 2.5; p = 0.01), and with persons met online (OR = 4.5; p = 0.04). Unprotected sex with persons of unknown HIV-serostatus was more often indicated by cases than controls (OR = 3.0; p = 0.003). Having a conversation about HIV serostatus before having sex was associated with a lower risk of infection (OR = 0.2; p = 0.01). In multivariate analysis “being always safe” (always using a condom when having sex in different situations outside of a relationship) and talking about serostatus before sex (OR = 0.23; p = 0.004; OR = 0.14; p = 0.014) were negatively associated with HIV- infection. Conclusions There were no significant differences regarding knowledge about HIV-transmission risks among cases and controls. Differences in risk behaviour were observed regarding unprotected sex with partners of unknown HIV-serostatus and duration of primary partnership at the time of diagnosis, suggesting some HIV-transmissions occurring in newly formed partnerships. The practice of discussing serostatus with prospective sex partners before engaging in sex seems to be protective for HIV-transmission.
    BMC Public Health 05/2014; 14(1):453. DOI:10.1186/1471-2458-14-453 · 2.26 Impact Factor
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    • "Our study also confirmed the finding from our previous study that UAI with casual male sexual partners was a risk factor for HIV infection [16]. Although HIV serosorting is considered an effective risk reduction strategy among high risk MSM in the USA [28], this strategy may not be so beneficial for Chinese MSM, because the benefit of this strategy relies on high coverage and frequency of HIV testing [29], while in 2009 only 43.7% of Chinese MSM had ever taken an HIV testing in the past 12 months [30]. "
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    ABSTRACT: Objective: To investigate the prevalence of recreational drug use and its relationship with HIV infection among Chinese MSM. Methods: A cross-sectional study of 625 MSM was conducted in Shenyang, China. Questionnaires were administered to collect information on recreational drug use and sexual behaviors. Blood specimens were collected to test for HIV and syphilis antibodies. Results: Nearly a quarter (23.2%, 145/625) of participants reported ever using recreational drugs, among which alkyl nitrites (poppers) was the most frequently used drug (19.2%), followed by methylmorphine phosphate (5.1%), methamphetamine (4.0%), and ketamine (0.8%). The overall prevalence of HIV and syphilis was 9.6% and 10.4%, respectively. Multivariate logistic analysis showed that recreational drug use was significantly correlated with age ≤ 25 year (adjusted odds ratio [aOR] = 1.6, 95% CI, 1.1-2.9), single marital status (aOR = 2.1, 95% CI, 1.2-3.6), and seeking male sexual partners mainly through Internet (aOR = 1.8, 95% CI, 1.8-2.8). Recreational drug use was independently associated with an increased risk of HIV infection (aOR = 3.5, 95% CI, 2.0-6.2). Conclusions: Our study suggests that recreational drug use is popular among Chinese MSM and is associated with significantly increased HIV infection risk. HIV prevention intervention programs should reduce both drug use and risky sexual behaviors in this population.
    04/2014; 2014:725361. DOI:10.1155/2014/725361
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    • "First, seroadaptive behaviors do not offer protection from other STI nor from sexually transmitted hepatitis C infection – and the latter appears to be on the rise in recent years particularly among HIVpositive MSM (Danta & Dusheiko, 2009). Second, if seroadaptation has helped stabilized HIV incidence in San Francisco and Seattle (Truong et al., 2006; Cassels et al, 2009), these instances should not be complacently accepted as the rule in a world where HIV epidemics are resurging among MSM in the West, only recently recognized in sub-Saharan Africa, and newly emerging in the rest of the developing world (van Griensven, Baral, & Grulich, 2009). "
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    ABSTRACT: "Seroadaptation" comprises sexual behaviors to reduce the risk of HIV acquisition and transmission based on knowing one's own and one's sexual partners' serostatus. We measured the prevalence of seroadaptive behaviors among men who have sex with men (MSM) recruited through time-location sampling (TLS) across three perspectives: by individuals (N = 1207 MSM), among sexual dyads (N = 3746 partnerships), and for sexual episodes (N = 63,789 episodes) in the preceding six months. Seroadaptation was more common than 100% condom use when considering the consistent behavioral pattern of individuals (adopted by 39.1% vs. 25.0% of men, respectively). Among sexual dyads 100% condom use was more common than seroadaptation (33.1% vs. 26.4%, respectively). Considering episodes of sex, not having anal intercourse (65.0%) and condom use (16.0%) were the most common risk reduction behaviors. Sex of highest acquisition and transmission risks (unprotected anal intercourse with a HIV serodiscordant or unknown status partner in the riskier position) occurred in only 1.6% of sexual episodes. In aggregate, MSM achieve a high level of sexual harm reduction through multiple strategies. Detailed measures of seroadaptive behaviors are needed to effectively target HIV risk and gauge the potential of serosorting and related sexual harm reduction strategies on the HIV epidemic.
    AIDS Care 03/2011; 23(3):261-8. DOI:10.1080/09540121.2010.507748 · 1.60 Impact Factor
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