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: In this paper, the authors analyzed longitudinal data for HIV-negative/unknown and HIV-positive serostatus participants in the Momentum Health Study in British Columbia and found that both groups reported using VLS, and that serastatus and treatment optimism scale scores were significant determinants in frequency and use.
Abstract: British Columbia’s treatment as prevention policy has provided free access to highly active antiretroviral therapy (HAART) to all HIV-positive provincial residents since 1996. One outcome is an increase in HIV-positive gay and bisexual men (GBM) with suppressed viral loads. Previous cross-sectional analyses indicated that some Vancouver GBM now recognize condomless anal sex with men on HAART who report a suppressed viral load as a seroadaptive strategy. To test the hypothesis that this new strategy, termed viral load sorting (VLS), is recognized and used among by GBM in the Momentum Health Study, we analyzed longitudinal data for HIV-negative/unknown (n = 556) and HIV-positive (n = 218) serostatus participants. Analyses indicated that both groups reported VLS, and that serostatus and Treatment Optimism Scale scores were significant determinants in frequency and use. Results exemplify the medicalization of sex and Rogers’ Diffusion Of Preventative Innovations Model, and they have important implicat...
13 citations
TL;DR: The Lisbon Cohort of MSM (LCM) as discussed by the authors is an open prospective cohort study aiming to dynamically monitor the frequency of disease and its predictors, which is a valuable tool for monitoring HIV incidence in a setting where limited prospective information existed.
Abstract: Purpose Newly diagnosed HIV infections among men who have sex with men (MSM) are rising in many European countries. Surveillance tools must be tailored to the current state of the epidemic, and include decentralised prospective monitoring of HIV incidence and behavioural changes in key populations. In this scenario, an open prospective cohort study was assembled—The Lisbon Cohort of MSM—aiming to dynamically monitor the frequency of disease and its predictors. Participants The Lisbon Cohort of MSM is an ongoing observational prospective study conducted at a community-based voluntary HIV counselling and testing centre in Lisbon, Portugal (CheckpointLX). Men testing negative for HIV, aged 18 or over and reporting having had sex with men are invited to follow-up visits every 6 months. At each evaluation, a face-to-face interview using a structured questionnaire is conducted, and HIV and syphilis rapid tests are performed by trained peer counsellors. From April 2011 to February 2014, 3106 MSM were eligible to the cohort of whom 923 (29.7%) did not participate. The remaining 2183 (70.3%) MSM were enrolled and 804 had at least one follow-up evaluation, for a total of 893 person-years of observation. Future plans The study findings will be disseminated in peer-reviewed journals and presented at national and international conferences. The follow-up of this cohort of HIV-negative MSM will be a valuable tool for monitoring HIV incidence in a setting where limited prospective information existed. Moreover, it will allow for a deeper analytical approach to the study of population time trends and individual changes in risk factors that currently shape the HIV epidemic among MSM.
13 citations
TL;DR: The extra genital sites need to be considered to break the HIV and bacterial sexually transmitted infections chain-of-transmission, and missed opportunities for diagnosis inextra genital sites could impact on HIV transmission.
Abstract: Background Infections caused by Chlamydia trachomatis and Neisseria gonorrhoeae are the most common bacterial sexually transmitted infections throughout the world. These sexually transmitted infections are a growing problem in people living with HIV/AIDS. However, the presence of these agents in extra genital sites, remains poorly studied in our country. The objective of this study was to estimate the prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae anal and genital infection in people living with HIV/AIDS followed in a reference center in Salvador, Brazil. Methods Cross-sectional study, from June 2013 to June 2015. Proven HIV-infected people attending this reference center were invited. Clinical and epidemiological data were obtained through interview with standardized form. Chlamydia trachomatis and Neisseria gonorrhoeae screening was performed using qPCR (COBAS 4800 ® Roche). Results The frequency of positive cases of Chlamydia trachomatis and Neisseria gonorrhoeae was 12.3% in total, 9.2% cases amongst women and 17.1% amongst men. We found 14.0% of positive cases in anus and 3.1% in genital region in men, while 5.6% and 3.6%, in women, respectively. Among men, anal infection was associated with age p = 0.033), report of anal intercourse ( p = 0.029), pain during anal intercourse ( p = 0.028). On the other hand, no association between genital infection and other variables were detected in bivariate analysis. Among women, we detected an association between Chlamydia trachomatis genital infection and age p p = 0.048), pregnancy ( p 50 copies/mL ( p = 0.020), and no antiretroviral use ( p = 0.008). Anal infection in women was associated with age p p = 0.023), and was not associated with report of anal intercourse ( p = 0.485). Conclusion Missed opportunities for diagnosis in extra genital sites could impact on HIV transmission. The extra genital sites need to be considered to break the HIV and bacterial sexually transmitted infections chain-of-transmission.
13 citations
TL;DR: More than half of syphilis case-persons identified with HIV had a detectable VL collected within 6 months of the syphilis diagnosis, which suggests virologic and active behavioral risk for transmitting HIV.
Abstract: BACKGROUND Incident syphilis among HIV-infected persons indicates the ongoing behavioral risk for HIV transmission. Detectable viral loads (VLs) among coinfected cases may amplify this risk. METHODS Primary and secondary cases reported during 2009-2010 from 4 US sites were crossmatched with local HIV surveillance registries to identify syphilis case-persons infected with HIV before or shortly after the syphilis diagnosis. We examined HIV VL and CD4 results collected within 6 months before or after syphilis diagnosis for the coinfected cases identified. Independent correlates of detectable VLs (≥200 copies/mL) were determined. RESULTS We identified 1675 cases of incident primary or secondary syphilis among persons with HIV. Median age was 37 years; 99.5% were men, 41.1% were African American, 24.5% were Hispanics, and 79.9% of the HIV diagnoses were made at least 1 year before syphilis diagnosis. Among those coinfected, there were no VL results reported for 188 (11.2%); of the 1487 (88.8%) with reported VL results, 809 (54.4%) had a detectable VL (median, 25,101 copies/mL; range, 206-3,590,000 copies/mL). Detectable VLs independently correlated with syphilis diagnosed at younger age, at an sexually transmitted disease clinic, and closer in time to HIV diagnosis. CONCLUSIONS More than half of syphilis case-persons identified with HIV had a detectable VL collected within 6 months of the syphilis diagnosis. This suggests virologic and active behavioral risk for transmitting HIV.
13 citations
TL;DR: A cross-sectional, clinic-based survey of border-region Latino men who have sex with men and who also are living with HIV in the El Paso-Ciudad Juárez area found psychological distress and problematic alcohol use were common in the sample and are important targets for intervention in their own right.
Abstract: We present results from a cross-sectional, clinic-based survey of border-region Latino men who have sex with men (MSM) and who also are living with HIV in the El Paso-Ciudad Juarez area. Among the 66 participants who reported serodiscordant anal or vaginal intercourse, we examined levels of psychological distress and substance use and the association of these variables with condomless sex. Bivariate analyses indicated that MSM who reported condomless sex with a serodiscordant partner were more likely to report higher scores on measures of anxiety, depression, and trauma. These men were also more likely to report more days of alcohol use to the point of intoxication. In multivariate logistic regression, no variables were independently associated with sexual risk behavior, but symptoms of anxiety trended toward statistical significance. Our study is one of few reports aimed at understanding the HIV epidemic among Latino MSM living with HIV in the El Paso-Ciudad Juarez border region. Although we found no evidence of a relation between our measures of psychological distress and substance use and sexual risk behavior in multivariate analyses, psychological distress and problematic alcohol use were common in the sample and are important targets for intervention in their own right.
13 citations
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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
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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 ...
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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