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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University of Colorado Denver1, University of California, San Francisco2, Asociación Civil Impacta Salud y Educación3, Oswaldo Cruz Foundation4, Chiang Mai University5, Federal University of Rio de Janeiro6, University of Cape Town7, Brown University8, University of São Paulo9, National Institutes of Health10
TL;DR: Oral FTC-TDF provided protection against the acquisition of HIV infection among the subjects and Detectable blood levels strongly correlated with the prophylactic effect.
Abstract: The study subjects were followed for 3324 person-years (median, 1.2 years; maximum, 2.8 years). Of these subjects, 10 were found to have been infected with HIV at en rollment, and 100 became infected during follow-up (36 in the FTC–TDF group and 64 in the placebo group), indicating a 44% reduction in the incidence of HIV (95% confidence interval, 15 to 63; P = 0.005). In the FTC–TDF group, the study drug was detected in 22 of 43 of seronegative subjects (51%) and in 3 of 34 HIV-infected subjects (9%) (P<0.001). Nausea was reported more frequently during the first 4 weeks in the FTC–TDF group than in the placebo group (P<0.001). The two groups had similar rates of serious adverse events (P = 0.57). Conclusions Oral FTC–TDF provided protection against the acquisition of HIV infection among the subjects. Detectable blood levels strongly correlated with the prophylactic effect. (Funded by the National Institutes of Health and the Bill and Melinda Gates Foun dation; ClinicalTrials.gov number, NCT00458393.)
4,247 citations
TL;DR: It is shown that the high probability of transmission per act through receptive anal intercourse has a central role in explaining the disproportionate disease burden in MSM and prevention strategies that lower biological transmission and acquisition risks offer promise.
1,369 citations
TL;DR: The findings suggest that transgender women are a very high burden population for HIV and are in urgent need of prevention, treatment, and care services.
Abstract: Summary Background Previous systematic reviews have identified a high prevalence of HIV infection in transgender women in the USA and in those who sell sex (compared with both female and male sex workers). However, little is known about the burden of HIV infection in transgender women worldwide. We aimed to better assess the relative HIV burden in all transgender women worldwide. Methods We did a systematic review and meta-analysis of studies that assessed HIV infection burdens in transgender women that were published between Jan 1, 2000, and Nov 30, 2011. Meta-analysis was completed with the Mantel-Haenszel method, and random-effects modelling was used to compare HIV burdens in transgender women with that in adults in the countries for which data were available. Findings Data were only available for countries with male-predominant HIV epidemics, which included the USA, six Asia-Pacific countries, five in Latin America, and three in Europe. The pooled HIV prevalence was 19·1% (95% CI 17·4–20·7) in 11 066 transgender women worldwide. In 7197 transgender women sampled in ten low-income and middle-income countries, HIV prevalence was 17·7% (95% CI 15·6–19·8). In 3869 transgender women sampled in five high-income countries, HIV prevalence was 21·6% (95% CI 18·8–24·3). The odds ratio for being infected with HIV in transgender women compared with all adults of reproductive age across the 15 countries was 48·8 (95% CI 21·2–76·3) and did not differ for those in low-income and middle-income countries compared with those in high-income countries. Interpretation Our findings suggest that transgender women are a very high burden population for HIV and are in urgent need of prevention, treatment, and care services. The meta-analysis showed remarkable consistency and severity of the HIV disease burden among transgender women. Funding Center for AIDS Research at Johns Hopkins and the Center for Public Health and Human Rights at the JHU Bloomberg School of Public Health.
1,142 citations
University College London1, University of Copenhagen2, University of St. Gallen3, University of Hamburg4, Hospital Clínico San Carlos5, University of Liverpool6, Universidad Miguel Hernández de Elche7, University of Victoria8, University of Zurich9, Karolinska University Hospital10, University of Bern11, Medical University of Vienna12, University Hospital of Basel13, Praxis14, Helsinki University Central Hospital15, Warwickshire Hospital16
TL;DR: Evaluating the rate of within-couple HIV transmission among serodifferent heterosexual and MSM couples during periods of sex without condoms and when the HIV-positive partner had HIV-1 RNA load less than 200 copies/mL found no phylogenetically linked transmissions.
Abstract: Importance A key factor in assessing the effectiveness and cost-effectiveness of antiretroviral therapy (ART) as a prevention strategy is the absolute risk of HIV transmission through condomless sex with suppressed HIV-1 RNA viral load for both anal and vaginal sex. Objective To evaluate the rate of within-couple HIV transmission (heterosexual and men who have sex with men [MSM]) during periods of sex without condoms and when the HIV-positive partner had HIV-1 RNA load less than 200 copies/mL. Design, Setting, and Participants The prospective, observational PARTNER (Partners of People on ART—A New Evaluation of the Risks) study was conducted at 75 clinical sites in 14 European countries and enrolled 1166 HIV serodifferent couples (HIV-positive partner taking suppressive ART) who reported condomless sex (September 2010 to May 2014). Eligibility criteria for inclusion of couple-years of follow-up were condomless sex and HIV-1 RNA load less than 200 copies/mL. Anonymized phylogenetic analysis compared couples’ HIV-1 polymerase and envelope sequences if an HIV-negative partner became infected to determine phylogenetically linked transmissions. Exposures Condomless sexual activity with an HIV-positive partner taking virally suppressive ART. Main Outcomes and Measures Risk of within-couple HIV transmission to the HIV-negative partner Results Among 1166 enrolled couples, 888 (mean age, 42 years [IQR, 35-48]; 548 heterosexual [61.7%] and 340 MSM [38.3%]) provided 1238 eligible couple-years of follow-up (median follow-up, 1.3 years [IQR, 0.8-2.0]). At baseline, couples reported condomless sex for a median of 2 years (IQR, 0.5-6.3). Condomless sex with other partners was reported by 108 HIV-negative MSM (33%) and 21 heterosexuals (4%). During follow-up, couples reported condomless sex a median of 37 times per year (IQR, 15-71), with MSM couples reporting approximately 22 000 condomless sex acts and heterosexuals approximately 36 000. Although 11 HIV-negative partners became HIV-positive (10 MSM; 1 heterosexual; 8 reported condomless sex with other partners), no phylogenetically linked transmissions occurred over eligible couple-years of follow-up, giving a rate of within-couple HIV transmission of zero, with an upper 95% confidence limit of 0.30/100 couple-years of follow-up. The upper 95% confidence limit for condomless anal sex was 0.71 per 100 couple-years of follow-up. Conclusions and Relevance Among serodifferent heterosexual and MSM couples in which the HIV-positive partner was using suppressive ART and who reported condomless sex, during median follow-up of 1.3 years per couple, there were no documented cases of within-couple HIV transmission (upper 95% confidence limit, 0.30/100 couple-years of follow-up). Additional longer-term follow-up is necessary to provide more precise estimates of risk.
1,039 citations
Additional excerpts
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TL;DR: The role of immune activation in the pathogenesis of non-AIDS clinical events (major causes of morbidity and mortality in people on antiretroviral therapy) is receiving increased recognition and breakthroughs in the prevention of HIV important to public health include male medical circumcision.
687 citations
References
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6 citations
TL;DR: It was not possible to determine significant differences in sexual practices, drug use, length of relationship, or numbers of different sexual partners between symptomatic and asymptomatic contacts or between seropositive and seronegative contacts in this study.
Abstract: Twenty homosexual men who reported having sexual contact with homosexual men who had the acquired immunodeficiency syndrome (AIDS) or the AIDS-related complex were examined to determine their clinical status, immunologic profiles, and the presence of antibody to the human T-cell lymphotropic virus type III (HTLV-III). Of the 20, eight men had one or more signs or symptoms of the AIDS-related complex and 12 were asymptomatic. Antibodies to HTLV-III were present in 14 (70%) of 20 of the sexual contacts as compared with four (10%) of 40 healthy homosexuals without known contact with a patient who had AIDS (P less than .0001). Seropositive contacts had significantly higher mean counts of suppressor lymphocytes and lower helper: suppressor ratios (P less than .05 and .005, respectively) and higher serum levels of IgG than seronegative contacts (P less than .05). It was not possible to determine significant differences in sexual practices, drug use, length of relationship, or numbers of different sexual partners between symptomatic and asymptomatic contacts or between seropositive and seronegative contacts in this study.
2 citations
Journal Article•
TL;DR: GPs appeared to have difficulty in diagnosing genital herpes in these patients, with the result of prescription of inappropriate and expensive medications.
Abstract: An audit was carried out of all cases of genital herpes referred by a general practitioner to a department of genito-urinary medicine from 1987-1990. Attention was paid as to whether or not the diagnosis had been made correctly and what drugs, if any, the patient had been prescribed. A total of 196 patients (78 men, 118 women) were eligible for study. GPs correctly diagnosed herpes in 32/78 (41%) of the men. Among the 46 who were not diagnosed, 12 were prescribed antibacterial drugs, three were prescribed antifungal cream, two were prescribed a combination of the above and three received miscellaneous non-antiviral agents. GPs correctly diagnosed 56/118 (47%) of the women. Sixty-two women were not diagnosed, of whom 17 were prescribed anti-bacterial drugs, 21 were prescribed antifungal cream, seven were prescribed a combination of these and six received miscellaneous non-antiviral agents. GPs appeared to have difficulty in diagnosing genital herpes in these patients, with the result of prescription of inappropriate and expensive medications.
1 citations