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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TL;DR: Targeted interventions can be implemented to increase knowledge about sexual partner’s HIV status, both among HIV-negative and HIV-positive MSM, to reduce the risk of HIV acquisition and transmission.
Abstract: Ukraine has among the highest rates of newly diagnosed HIV infections in the WHO European region. Men who have sex with men (MSM) is the least studied group in the context of the HIV epidemics in Ukraine. The present paper aims to estimate the prevalence and correlates of knowledge of sexual partner’s HIV status and potentially discordant anal intercourse (failure to serosort) among MSM. Data of the cross-sectional study among 8100 MSM in Ukraine in 2013 were used for this analysis. Less than half of the participants (42.5%) reported that they knew the HIV serostatus of their most recent male sexual partner, and about 13% of participants reported failure to serosort during their most recent anal sexual intercourse with a male partner. Targeted interventions can be implemented to increase knowledge about sexual partner’s HIV status, both among HIV-negative and HIV-positive MSM, to reduce the risk of HIV acquisition and transmission.
5 citations
TL;DR: The efficacy of combining a DNA/virus-like particle (VLP) vaccine with partially effective intermittent PrEP with antiretrovirals was determined in Indian rhesus macaques.
Abstract: Vaccination and preexposure prophylaxis (PrEP) with antiretrovirals have shown only partial protection from HIV-1 infection in human trials. Oral Truvada (emtricitabine/tenofovir disoproxil fumarate) is FDA approved as PrEP but partial adherence reduces efficacy. If combined as biomedical preventions (CBP), an HIV vaccine could protect when PrEP adherence is low and PrEP could prevent vaccine breakthroughs. The efficacy of combining oral PrEP with an HIV vaccine has not been evaluated in humans. We determined the efficacy of combining a DNA/virus-like particle (VLP) vaccine with partially effective intermittent PrEP in Indian rhesus macaques (RM). Eight RM received intramuscular inoculations of five DNA plasmids encoding four HIV-1 Clade B primary isolate Envs and SIVmac239 Gag (at weeks 0 and 4), followed by intramuscular and intranasal inoculations of homologous Gag VLPs and four Env VLPs (at weeks 12, 16, and 53). At week 61, we initiated weekly rectal exposures with heterologous SHIV162p3 (10...
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15 Sep 2016
TL;DR: The new biomedical technologies and strategies for the prevention of HIV and other sexually transmitted infections are discussed.
Abstract: Sexually transmitted infections remain to be of public health concern in many developing countries. Their control is important, considering the high incidence of acute infections, complications and sequelae, and their socioeconomic impact. This article discusses the new biomedical technologies and strategies for the prevention of HIV and other sexually transmitted infections.
5 citations
Cites background from "HIV transmission risk through anal ..."
...Despite the fact that anal intercourse increases the risk of HIV infection by as much as 10 to 20 percent compared to vaginal intercourse [46], most research on microbicides has been focused on vaginal intercourse....
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TL;DR: Sexual bridging between MSM and women likely varies geographically and is probably bi-directional, occurring within a generalized epidemic where HIV prevalence is higher among reproductive-age women than MSM.
Abstract: African men who have sex with men (MSM) frequently, and often concurrently, have female partners, raising concerns about HIV sexual bridging. We explored potential HIV transmission in Mozambique from and to female partners of MSM focusing on preferred anal sex role and circumcision status. Data collected in a respondent-driven sampling study of MSM in 2011 in Maputo and Beira. Men who had oral or anal sex with other men 12 months prior completed a questionnaire and consented for HIV testing. Statistical analysis explored demographic/risk characteristics and associations among circumcision status, anal sex with men, sexual positions during anal sex with men and vaginal or anal sex with women. We identified 326 MSM in Maputo and 237 in Beira with both male and female partners 3 months before the study. Of these, 20.8% in Maputo and 36.0% in Beira had any receptive anal sex with men 12 months prior, including 895 unprotected sexual acts with males in Maputo and 692 in Beira. Uncircumcised and exclusively insertive males, 27.7% of the sample in Maputo and 33.6% in Beira, had the most unprotected sex with females: 1159 total acts in Maputo and 600 in Beira. Sexual bridging between MSM and women likely varies geographically and is probably bi-directional, occurring within a generalized epidemic where HIV prevalence is higher among reproductive-age women than MSM. Prevention strategies emphasizing correct and consistent condom use for all partners and circumcision for bisexual men should be considered.
5 citations
Posted Content•
TL;DR: In this article, the authors identify logical and due process errors in HIV-related aggravated assault cases, which usually involve an HIV-positive individual having unprotected sex without disclosing his or her HIV status, and suggest that punishing this conduct through a charge of aggravated assault - which requires a showing that the defendant's actions were a means likely to cause grievous bodily harm or death - is fraught with fallacies in reasoning and runs afoul of due process.
Abstract: This Article identifies logical and due process errors in HIV-related aggravated assault cases, which usually involve an HIV-positive individual having unprotected sex without disclosing his or her HIV status. While this behavior should not be encouraged, this Article suggests that punishing this conduct through a charge of aggravated assault - which requires a showing that the defendant’s actions were a means likely to cause grievous bodily harm or death - is fraught with fallacies in reasoning and runs afoul of due process. Specifically, some courts use the "rule of thumb" that HIV can possibly be transmitted through bodily fluids as sufficient evidence for finding that a particular HIV-positive defendant who had unprotected sex did so in a manner likely to cause substantial harm. This leads to two due process errors: (1) the conflation of what is theoretically possible for what is likely, and (2) the use of data about a hypothetical, average, HIV-positive individual as proof of the effects of a particular HIV-positive individual’s behavior. By relying on the rule of thumb that HIV can be transmitted through bodily fluids rather than investigating the unique features of the particular defendant on trial, these jurisdictions violate the Due Process Clause’s requirement of "personal guilt." Aristotle’s "Fallacy of Accident" is then committed when this generalization is applied to an HIV-positive defendant whose viral load is undetectable, making him an exception to the general rule. After explaining these concepts, this Article identifies various cases from the states and the military that commit these errors. These cases are then compared to similar aggravated assault cases from Canada that do not make the same mistakes and use the kind of particularized proof that is required by both common logic and the Due Process Clause.
5 citations
References
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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
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
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
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
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