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Journal ArticleDOI

HIV transmission risk through anal intercourse: systematic review, meta-analysis and implications for HIV prevention

01 Aug 2010-International Journal of Epidemiology (Oxford University Press)-Vol. 39, Iss: 4, pp 1048-1063
TL;DR: It was demonstrated that it would require unreasonably low numbers of AI HIV exposures per partnership to reconcile the summary per-act and per-partner estimates, suggesting considerable variability in AI infectiousness between and within partnerships over time.
Abstract: Background The human immunodeficiency virus (HIV) infectiousness of anal intercourse (AI) has not been systematically reviewed, despite its role driving HIV epidemics among men who have sex with men (MSM) and its potential contribution to heterosexual spread. We assessed the per-act and per-partner HIV transmission risk from AI exposure for heterosexuals and MSM and its implications for HIV prevention. Methods Systematic review and meta-analysis of the literature on HIV-1 infectiousness through AI was conducted. PubMed was searched to September 2008. A binomial model explored the individual risk of HIV infection with and without highly active antiretroviral therapy (HAART). Results A total of 62 643 titles were searched; four publications reporting per-act and 12 reporting per-partner transmission estimates were included. Overall, random effects model summary estimates were 1.4% [95% confidence interval (CI) 0.2–2.5)] and 40.4% (95% CI 6.0–74.9) for per-act and per-partner unprotected receptive AI (URAI), respectively. There was no significant difference between per-act risks of URAI for heterosexuals and MSM. Per-partner unprotected insertive AI (UIAI) and combined URAI–UIAI risk were 21.7% (95% CI 0.2–43.3) and 39.9% (95% CI 22.5–57.4), respectively, with no available per-act estimates. Per-partner combined URAI–UIAI summary estimates, which adjusted for additional exposures other than AI with a ‘main’ partner [7.9% (95% CI 1.2–14.5)], were lower than crude (unadjusted) estimates [48.1% (95% CI 35.3–60.8)]. Our modelling demonstrated that it would require unreasonably low numbers of AI HIV exposures per partnership to reconcile the summary per-act and per-partner estimates, suggesting considerable variability in AI infectiousness between and within partnerships over time. AI may substantially increase HIV transmission risk even if the infected partner is receiving HAART; however, predictions are highly sensitive to infectiousness assumptions based on viral load. Conclusions Unprotected AI is a high-risk practice for HIV transmission, probably with substantial variation in infectiousness. The significant heterogeneity between infectiousness estimates means that pooled AI HIV transmission probabilities should be used with caution. Recent reported rises in AI among heterosexuals suggest a greater understanding of the role AI plays in heterosexual sex lives may be increasingly important for HIV prevention.

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Journal ArticleDOI
TL;DR: It is found that positive attitudes toward positive outcomes regarding CAI were most strongly associated with high CAI intention and the importance of tailoring HIV prevention initiatives for young MSM of different sexual roles to optimize the program effectiveness is highlighted.
Abstract: In recent years, men who have sex with men (MSM) have accounted for over 80% of all new HIV cases in Taiwan. More than 70% of new cases have occurred in those aged 15–34 years. Condomless anal intercourse (CAI) has been identified as the main route of HIV transmission among MSM. To systematically examine CAI intention and associated factors among young MSM in Taiwan, an anonymous online survey based on the Theory of Planned Behavior (TPB) was conducted. Data from 694 MSM aged 15–39 years were included in the analysis. This study found that, overall, all five TPB factors (i.e., attitudes toward positive and negative outcomes regarding CAI, perceived support for CAI from important others, and perceived behavioral control of CAI under facilitating and constraining conditions) were significantly associated with CAI intention. When data were stratified by sexual role (i.e., receptive, versatile, and insertive), the associations between TPB factors and CAI intention varied. Of the five TPB factors, positive attitudes toward positive outcomes regarding CAI were most strongly associated with high CAI intention (AOR 5.68 for all young MSM; AOR 3.80–15.93, depending on sexual role). Findings from this study could inform the development of theory-driven HIV prevention programs as well as future research and practice. These results also highlight the importance of tailoring HIV prevention initiatives for young MSM of different sexual roles to optimize the program effectiveness.

6 citations

Journal ArticleDOI
TL;DR: There is a need to broaden heterosexual sexual health promotion and HIV/sexually transmitted infection prevention to adequately and appropriately address risks and prevention strategies for anal intercourse.
Abstract: BackgroundUnderstanding and addressing heterosexual HIV transmission requires attention to the range and context of heterosexual sexual behaviors. We sought to determine population-based prevalence of condomless anal intercourse (CAI) among individuals at increased heterosexual HIV risk in Baltimore

6 citations

Journal ArticleDOI
23 Aug 2018
TL;DR: Should future research support its efficacy in facilitating behavior change, Game Plan could represent a wide-reaching and scalable tool that is well-suited for use in settings where delivering evidence-based, in-person interventions would be difficult or cost-prohibitive.
Abstract: Background Men who have sex with men (MSM) are at high risk for HIV, and alcohol use is a major risk factor for HIV infection. Internet-facilitated brief interventions have been shown to reduce alcohol use and HIV-risk behavior in other at-risk populations, but have so far incorporated limited content and have not been tested among MSM. Objective This manuscript describes Game Plan, an interactive, tablet-optimized web application designed to help heavy drinking, high-risk MSM consider reducing their alcohol use and sexual risk behavior. In this paper, we discuss the rationale, goals, and flow for each of Game Plan's components, which were modelled after common in-person and web-based brief motivational interventions for these behaviors. Methods The development of Game Plan was informed by a thorough user-focused design research process that included (1) audits of existing interventions, (2) focus groups with stakeholders and (3) intended users (high-risk, heavy drinking MSM), and (4) usability testing. The aesthetic, features, and content of the app were designed iteratively throughout this process. Results The fully-functional Game Plan app provides (1) specific and personal feedback to users about their level of risk, (2) exercises to help prompt users to reflect on whether their current behavior aligns with other important life goals and values, and for those open to change, (3) exercises to help users understand factors that contribute to risk, and (4) a change planning module. In general, this flow was constructed to roughly align with the two phases described in early accounts of motivational interviewing (MI): (1) Content intended to elicit intrinsic motivation for change, and when/if sufficient motivation is present, (2) content intended to translate that motivation into specific goals and plans for change. This sequence first focuses on the user's HIV risk behavior, followed by their alcohol use and the connection between the two. The app's overall aesthetic (eg, branding, color palettes, icons/graphics) and its onboarding sequence was also designed to align with the "spirit" of MI by conveying respect for autonomy, open-mindedness (ie, avoiding judgment), and empathy. Conclusions Should future research support its efficacy in facilitating behavior change, Game Plan could represent a wide-reaching and scalable tool that is well-suited for use in settings where delivering evidence-based, in-person interventions would be difficult or cost-prohibitive.

6 citations


Cites methods from "HIV transmission risk through anal ..."

  • ...This section provides personal, easy-to-understand estimates of users’ potential risk for HIV in the past year given their current sexual behavior during that time and their projected 5-year risk using data from past research [62-65]....

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Journal ArticleDOI
19 Mar 2018-PLOS ONE
TL;DR: Different disease progression assumptions on and post-ART interruption did not affect the fraction of HIV infections averted with expanded ART, unless ART dropouts only re-initiated ART at low CD4 counts.
Abstract: BACKGROUND Many mathematical models have investigated the population-level impact of expanding antiretroviral therapy (ART), using different assumptions about HIV disease progression on ART and among ART dropouts. We evaluated the influence of these assumptions on model projections of the number of infections and deaths prevented by expanded ART. METHODS A new dynamic model of HIV transmission among men who have sex with men (MSM) was developed, which incorporated each of four alternative assumptions about disease progression used in previous models: (A) ART slows disease progression; (B) ART halts disease progression; (C) ART reverses disease progression by increasing CD4 count; (D) ART reverses disease progression, but disease progresses rapidly once treatment is stopped. The model was independently calibrated to HIV prevalence and ART coverage data from the United States under each progression assumption in turn. New HIV infections and HIV-related deaths averted over 10 years were compared for fixed ART coverage increases. RESULTS Little absolute difference (<7 percentage points (pp)) in HIV infections averted over 10 years was seen between progression assumptions for the same increases in ART coverage (varied between 33% and 90%) if ART dropouts reinitiated ART at the same rate as ART-naive MSM. Larger differences in the predicted fraction of HIV-related deaths averted were observed (up to 15pp). However, if ART dropouts could only reinitiate ART at CD4<200 cells/μl, assumption C predicted substantially larger fractions of HIV infections and deaths averted than other assumptions (up to 20pp and 37pp larger, respectively). CONCLUSION Different disease progression assumptions on and post-ART interruption did not affect the fraction of HIV infections averted with expanded ART, unless ART dropouts only re-initiated ART at low CD4 counts. Different disease progression assumptions had a larger influence on the fraction of HIV-related deaths averted with expanded ART.

6 citations

References
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Journal ArticleDOI
04 Sep 2003-BMJ
TL;DR: A new quantity is developed, I 2, which the authors believe gives a better measure of the consistency between trials in a meta-analysis, which is susceptible to the number of trials included in the meta- analysis.
Abstract: Cochrane Reviews have recently started including the quantity I 2 to help readers assess the consistency of the results of studies in meta-analyses. What does this new quantity mean, and why is assessment of heterogeneity so important to clinical practice? Systematic reviews and meta-analyses can provide convincing and reliable evidence relevant to many aspects of medicine and health care.1 Their value is especially clear when the results of the studies they include show clinically important effects of similar magnitude. However, the conclusions are less clear when the included studies have differing results. In an attempt to establish whether studies are consistent, reports of meta-analyses commonly present a statistical test of heterogeneity. The test seeks to determine whether there are genuine differences underlying the results of the studies (heterogeneity), or whether the variation in findings is compatible with chance alone (homogeneity). However, the test is susceptible to the number of trials included in the meta-analysis. We have developed a new quantity, I 2, which we believe gives a better measure of the consistency between trials in a meta-analysis. Assessment of the consistency of effects across studies is an essential part of meta-analysis. Unless we know how consistent the results of studies are, we cannot determine the generalisability of the findings of the meta-analysis. Indeed, several hierarchical systems for grading evidence state that the results of studies must be consistent or homogeneous to obtain the highest grading.2–4 Tests for heterogeneity are commonly used to decide on methods for combining studies and for concluding consistency or inconsistency of findings.5 6 But what does the test achieve in practice, and how should the resulting P values be interpreted? A test for heterogeneity examines the null hypothesis that all studies are evaluating the same effect. The usual test statistic …

45,105 citations

Journal ArticleDOI
19 Apr 2000-JAMA
TL;DR: A checklist contains specifications for reporting of meta-analyses of observational studies in epidemiology, including background, search strategy, methods, results, discussion, and conclusion should improve the usefulness ofMeta-an analyses for authors, reviewers, editors, readers, and decision makers.
Abstract: ObjectiveBecause of the pressure for timely, informed decisions in public health and clinical practice and the explosion of information in the scientific literature, research results must be synthesized. Meta-analyses are increasingly used to address this problem, and they often evaluate observational studies. A workshop was held in Atlanta, Ga, in April 1997, to examine the reporting of meta-analyses of observational studies and to make recommendations to aid authors, reviewers, editors, and readers.ParticipantsTwenty-seven participants were selected by a steering committee, based on expertise in clinical practice, trials, statistics, epidemiology, social sciences, and biomedical editing. Deliberations of the workshop were open to other interested scientists. Funding for this activity was provided by the Centers for Disease Control and Prevention.EvidenceWe conducted a systematic review of the published literature on the conduct and reporting of meta-analyses in observational studies using MEDLINE, Educational Research Information Center (ERIC), PsycLIT, and the Current Index to Statistics. We also examined reference lists of the 32 studies retrieved and contacted experts in the field. Participants were assigned to small-group discussions on the subjects of bias, searching and abstracting, heterogeneity, study categorization, and statistical methods.Consensus ProcessFrom the material presented at the workshop, the authors developed a checklist summarizing recommendations for reporting meta-analyses of observational studies. The checklist and supporting evidence were circulated to all conference attendees and additional experts. All suggestions for revisions were addressed.ConclusionsThe proposed checklist contains specifications for reporting of meta-analyses of observational studies in epidemiology, including background, search strategy, methods, results, discussion, and conclusion. Use of the checklist should improve the usefulness of meta-analyses for authors, reviewers, editors, readers, and decision makers. An evaluation plan is suggested and research areas are explored.

17,663 citations

Journal ArticleDOI
TL;DR: The problem of making a combined estimate has been discussed previously by Cochran and Yates and Cochran (1937) for agricultural experiments, and by Bliss (1952) for bioassays in different laboratories as discussed by the authors.
Abstract: When we are trying to make the best estimate of some quantity A that is available from the research conducted to date, the problem of combining results from different experiments is encountered. The problem is often troublesome, particularly if the individual estimates were made by different workers using different procedures. This paper discusses one of the simpler aspects of the problem, in which there is sufficient uniformity of experimental methods so that the ith experiment provides an estimate xi of u, and an estimate si of the standard error of xi . The experiments may be, for example, determinations of a physical or astronomical constant by different scientists, or bioassays carried out in different laboratories, or agricultural field experiments laid out in different parts of a region. The quantity xi may be a simple mean of the observations, as in a physical determination, or the difference between the means of two treatments, as in a comparative experiment, or a median lethal dose, or a regression coefficient. The problem of making a combined estimate has been discussed previously by Cochran (1937) and Yates and Cochran (1938) for agricultural experiments, and by Bliss (1952) for bioassays in different laboratories. The last two papers give recommendations for the practical worker. My purposes in treating the subject again are to discuss it in more general terms, to take account of some recent theoretical research, and, I hope, to bring the practical recommendations to the attention of some biologists who are not acquainted with the previous papers. The basic issue with which this paper deals is as follows. The simplest method of combining estimates made in a number of different experiments is to take the arithmetic mean of the estimates. If, however, the experiments vary in size, or appear to be of different precision, the investigator may wonder whether some kind of weighted meani would be more precise. This paper gives recommendations about the kinds of weighted mean that are appropriate, the situations in which they

4,335 citations

Journal ArticleDOI
TL;DR: The viral load is the chief predictor of the risk of heterosexual transmission of HIV-1, and transmission is rare among persons with levels of less than 1500 copies of HIV -1 RNA per milliliter.
Abstract: Background and Methods We examined the influence of viral load in relation to other risk factors for the heterosexual transmission of human immunodeficiency virus type 1 (HIV-1). In a community-based study of 15,127 persons in a rural district of Uganda, we identified 415 couples in which one partner was HIV-1–positive and one was initially HIV-1–negative and followed them prospectively for up to 30 months. The incidence of HIV-1 infection per 100 person-years among the initially seronegative partners was examined in relation to behavioral and biologic variables. Results The male partner was HIV-1–positive in 228 couples, and the female partner was HIV-1–positive in 187 couples. Ninety of the 415 initially HIV-1–negative partners seroconverted (incidence, 11.8 per 100 person-years). The rate of male-to-female transmission was not significantly different from the rate of female-to-male transmission (12.0 per 100 person-years vs. 11.6 per 100 person-years). The incidence of seroconversion was highest among ...

2,897 citations

Journal ArticleDOI
TL;DR: A theoretical strategy of universal voluntary HIV testing and immediate treatment with ART, combined with present prevention approaches, could have a major effect on severe generalised HIV/AIDS epidemics.

1,948 citations

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