HIV-1 RNA rectal shedding is reduced in men with low plasma HIV-1 RNA viral loads and is not enhanced by sexually transmitted bacterial infections of the rectum

High-fat diet feeding exacerbates HIV-1 rectal transmission

High-fat diet (HFD) is well known to impact various aspects of gut health and has been associated with many diseases and inflammation. However, the impact of HFD feeding on HIV-1 rectal transmission has not yet been well addressed. With an increasing threat of HIV-1 infection in men who have sex with men (MSM), where the rectal route is the primary mode of infection, it is imperative to understand the impact of HFD on gut microbiota and inflammation and consequently, its effect on HIV-1 rectal transmission. Here, we utilized our double humanized bone marrow, liver, thymus (dHu-BLT) mouse model to assess the impact of HFD feeding on the host's susceptibility to HIV-1 rectal transmission. We found that feeding an HFD successfully altered the gut microbial composition within 3 weeks in the dHu-BLT mouse model. In addition, levels of inflammatory mediators, specifically IL-12p70, IP-10, ICAM-1, and fecal calprotectin, were significantly higher in HFD-fed mice compared to control mice on a regular chow diet. We also observed that significantly different inflammatory markers (IL-12p70 and ICAM-1) were negatively correlated with the number of observed ASVs, Shannon diversity, and Faith's diversity in the HFD-fed group. Notably, when repeatedly challenged with a low dose of HIV-1 via a rectal route, mice receiving an HFD were significantly more susceptible to HIV-1 rectal infection than control mice. Together, these results underscore the impact of HFD feeding on the gut microbiota and inflammation and suggest the significance of diet-induced gut microbial dysbiosis and inflammation in promoting viral infection.IMPORTANCEHFD induces gut microbial dysbiosis and inflammation and has been associated with many infections and disease progression; however, its impact on HIV-1 rectal transmission is largely unknown. Given the increasing threat of HIV-1 incidence in men who have sex with men (MSM), it has become crucial to comprehend the impact of factors associated with gut health, like HFD consumption, on host susceptibility to HIV-1 rectal transmission. This is particularly important since anal intercourse remains the primary mode of HIV transmission within the MSM group. In this study, utilizing our unique mouse model, featuring both the human immune system and gut microbiota, we showed that HFD feeding led to gut microbial dysbiosis, induced inflammation, and increased HIV-1 rectal transmission. Collectively, our study highlights the significant impact of HFD on gut microbiota and inflammation and suggests an HFD consumption as a potential risk factor for promoting HIV-1 rectal susceptibility.

Targeted delivery methods for RNA interference are necessary to obtain a potential functional cure for HIV/AIDS

Ribonucleic acid (RNA) is of great interest in many different therapeutic areas including infectious diseases such as immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). Thanks to current, advanced treatments for HIV, the diagnosis is no longer a death sentence. However, even with these treatments, latency is suggested to persist in T-lymphocyte-rich tissues including gut-associated lymphatic tissue (GALT), spleen, and bone marrow making HIV an incurable disease. Therefore, it is important to design systems that can effectively deliver therapeutics to these tissues to fight latent infection and find a functional cure. Numerous therapeutics ranging from small molecules to cell therapies have been explored as a cure for HIV but have failed to maintain therapeutic longevity. RNA interference (RNAi) provides a unique opportunity to achieve a functional cure for those who suffer from chronic HIV/AIDS by suppressing replication of the virus. However, RNA has certain imitations in delivery as it cannot be delivered without a carrier due to its negative charge and degradation from endogenous nucleases. Here, we provide a detailed analysis of explored systems for siRNA delivery for HIV/AIDS in the context of RNA therapeutic design and nanoparticle design. In addition, we suggest strategies that should be used to target specific tissues that are rich in lymphatic tissue.

Anatomic site-specific gonorrhea and chlamydia testing and incidence among people with HIV engaged in care at four United States clinical centers, 2014-2018

Background

The incidence of Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT) is increasing in the United States; however, there are limited data on anatomic site-specific GC/CT among people with HIV (PWH).

Methods

We reviewed records of all PWH in care between January 1, 2014 and November 16, 2018 at four sites in the CFAR Network of Integrated Clinical Systems Cohort (CNICS; N = 8455). We calculated anatomic site-specific GC/CT testing and incidence rates and used Cox proportional hazards models modified for recurrent events to examine sociodemographic and clinical predictors of GC/CT testing and incidence at urogenital, rectal, and pharyngeal sites. We also calculated site-specific number needed to test (NNT) to detect a positive GC/CT test.

Results

Of 8455 PWH, 2460 (29.1%) had at least yearly GC/CT testing at any anatomic site. The rates of urogenital, rectal, and pharyngeal GC were 1.7 (95%CI:1.6, 1.9), 3.2 (95%CI:3.0, 3.5), and 2.7 (95%CI:2.5, 2.9) infections per 100 person-years, respectively. The rates of urogenital, rectal, and pharyngeal CT were 1.9 (95%CI:1.7, 2.1), 4.3 (95%CI:4.0, 4.5), and 0.9 (95%CI:0.8, 1.0) infections per 100 person-years, respectively. PWH 16-39 years old experienced greater GC/CT rates at all anatomic sites while MSM experienced greater rates of extragenital infections. NNTs for urogenital, rectal, and pharyngeal GC/CT were 20 (95%CI:19, 21), 5 (95%CI:5, 5), and 9 (95%CI:8, 9), respectively.

Conclusion

Many PWH are not tested annually for GC/CT and rates of GC/CT infection, particularly rates of extragenital infections, are high. We identified groups of PWH who may benefit from increased site-specific GC/CT testing.

Rectal and seminal HIV-1 RNA decay towards virological suppression in infected MSM initiating dolutegravir/abacavir/lamivudine

BACKGROUND

The time at which the protective effect of starting ART is achieved in male rectal and genital reservoirs is not clearly established.

OBJECTIVES

To quantify HIV-1 RNA decay towards virological suppression in rectal mucosa and semen in MSM starting dolutegravir/abacavir/lamivudine (DTG/ABC/3TC).

METHODS

A longitudinal cohort study of ART-naive HIV-positive MSM was performed. HIV-1 RNA was quantified in rectal mucosa and seminal plasma samples at day 1 of ART initiation (baseline) and every 4 weeks until week 20 (w20; all participants) and week 64 (w64; 6 of 12 participants).

RESULTS

Twelve MSM, with median (IQR) age 36 (33-40) years and baseline CD4+ count 449 (411-503) cells/mm3, were included. At baseline, HIV-1 RNA was detectable in all plasma and seminal samples and 10/12 rectal samples. All participants achieved plasma virological suppression by w20, whereas HIV-1 RNA was detectable in 42% and 50% of seminal and rectal samples, respectively. At w64, HIV-1 RNA was detectable in 1/6 seminal and 1/6 rectal samples. A relationship of baseline seminal and rectal HIV-1 RNA levels with viral shedding in reservoirs (HIV-1 RNA >200 copies/mL or copies/swab) was found. In addition, a significant association of baseline plasma viral load with time to rectal HIV-1 RNA <200 copies/swab was found (P=0.025).

CONCLUSIONS

Viral decay after initiating DTG/ABC/3TC is slower in rectal mucosa and semen than in plasma. Approximately half of patients achieved undetectable HIV-1 RNA levels in rectal and genital secretions at w20 and in some patients viral shedding persisted for up to 1 year. Initial plasma viral load influences time to rectal suppression.

Anal dysplasia and HIV shedding in ART-treated men

OBJECTIVES

Anal human papillomavirus (HPV) infection is highly prevalent among men who have sex with men (MSM). HPV-associated anal dysplasia has been linked with anal HIV RNA shedding despite antiretroviral therapy (ART). Since mucosal HIV levels are a key determinant of sexual transmission of the virus, this would have important public health implications. Therefore, we assessed the association between anal dysplasia and HIV shedding in ART-treated MSM from Toronto, Canada.

METHODS

In 54 HIV-infected men on effective ART, we assessed anal HIV RNA shedding by PCR, HPV infection by microsphere-based genotyping and anal dysplasia by high-resolution anoscopy. All participants were enrolled between May 2017 and October 2018.

RESULTS

The median duration of ART at the time of study enrolment was 18 years, with most participants being on an integrase inhibitor-based ART regimen. Low-level anal HIV RNA shedding was present in 15/54 (27.8%) participants. Neither the detection of shedding nor the level of HIV RNA was associated with anal dysplasia, HPV infection or antiretroviral regimen.

CONCLUSIONS

HPV-associated anal dysplasia was not associated with anal HIV RNA shedding in this relatively small cohort of men on effective ART. While anal HIV RNA was detected more often than anticipated, shedding was low level and unlikely to cause HIV transmission. However, the immunological drivers of anal HIV RNA shedding in ART-treated individuals may merit further study.

Sexually transmitted infections and HIV in the era of antiretroviral treatment and prevention: the biologic basis for epidemiologic synergy

INTRODUCTION

HIV is a unique sexually transmitted infection (STI) that is greatly affected by other concomitant "classical" bacterial and viral STIs that cause genital ulcers and/or mucosal inflammation. STIs also serve as a marker for risky sexual behaviours. STIs increase infectiousness of people living with HIV by increasing the viral concentration in the genital tract, and by increasing the potential for HIV acquisition in people at risk for HIV. In addition, some STIs can increase blood HIV concentration and promote progression of disease. This review is designed to investigate the complex relationship between HIV and classical STIs.

DISCUSSION

Treatment of STIs with appropriate antibiotics reduces HIV in blood, semen and female genital secretions. However, community-based trials could not reliably reduce the spread of HIV by mass treatment of STIs. Introduction of antiretroviral agents for the treatment and prevention of HIV has led to renewed interest in the complex relationship between STIs and HIV. Antiretroviral treatment (ART) reduces the infectiousness of HIV and virtually eliminates the transmission of HIV in spite of concomitant or acquired STIs. However, while ART interrupts HIV transmission, it does not stop intermittent shedding of HIV in genital secretions. Such shedding of HIV is increased by STIs, although the viral copies are not likely replication competent or infectious. Pre-exposure prophylaxis (PrEP) of HIV with the combination of tenofovir disoproxil fumarate and emtricitabine (TDF/FTC) prevents HIV acquisition in spite of concomitant STIs.

CONCLUSIONS

STIs remain pandemic, and the availability of ART may have led to an increase in STIs, as fear of HIV has diminished. Classical STIs present a huge worldwide health burden that cannot be separated from HIV, and they deserve far more attention than they currently receive.

Heterogeneous antiretroviral drug distribution and HIV/SHIV detection in the gut of three species

HIV replication within tissues may increase in response to a reduced exposure to antiretroviral drugs. Traditional approaches to measuring drug concentrations in tissues are unable to characterize a heterogeneous drug distribution. Here, we used mass spectrometry imaging (MSI) to visualize the distribution of six HIV antiretroviral drugs in gut tissue sections from three species (two strains of humanized mice, macaques, and humans). We measured drug concentrations in proximity to CD3+ T cells that are targeted by HIV, as well as expression of HIV or SHIV RNA and expression of the MDR1 drug efflux transporter in gut tissue from HIV-infected humanized mice, SHIV-infected macaques, and HIV-infected humans treated with combination antiretroviral drug therapy. Serial 10-μm sections of snap-frozen ileal and rectal tissue were analyzed by MSI for CD3+ T cells and MDR1 efflux transporter expression by immunofluorescence and immunohistochemistry, respectively. The tissue slices were analyzed for HIV/SHIV RNA expression by in situ hybridization and for antiretroviral drug concentrations by liquid chromatography-mass spectrometry. The gastrointestinal tissue distribution of the six drugs was heterogeneous. Fifty percent to 60% of CD3+ T cells did not colocalize with detectable drug concentrations in the gut tissue. In all three species, up to 90% of HIV/SHIV RNA was found to be expressed in gut tissue with no exposure to drug. These data suggest that there may be gut regions with little to no exposure to antiretroviral drugs, which may result in low-level HIV replication contributing to HIV persistence.

HIV and SIV in Body Fluids: From Breast Milk to the Genitourinary Tract

HIV-1 is present in many secretions including oral, intestinal, genital, and breast milk. However, most people exposed to HIV-1 within these mucosal compartments do not become infected despite often frequent and repetitive exposure over prolonged periods of time. In this review, we discuss what is known about the levels of cell-free HIV RNA, cell-associated HIV DNA and cell-associated HIV RNA in external secretions. Levels of virus are usually lower than contemporaneously obtained blood, increased in settings of inflammation and infection, and decreased in response to antiretroviral therapy. Additionally, each mucosal compartment has unique innate and adaptive immune responses that affect the composition and presence of HIV-1 within each external secretion. We discuss the current state of knowledge about the types and amounts of virus present in the various excretions, touch on innate and adaptive immune responses as they affect viral levels, and highlight important areas for further study.

Microscopic examination of Gram-stained smears for anogenital gonorrhoea in men who have sex with men is cost-effective: evidence from a modelling study

OBJECTIVE

To assess the cost-effectiveness of three testing strategies with or without light microscopic Gram-stained smear (GSS) evaluation for the detection of anogenital gonorrhoea among men who have sex with men (MSM) at the Amsterdam STI clinic using a healthcare payer perspective.

METHODS

Three testing strategies for MSM were compared: (1) GSS in symptomatic MSM only (currently practised strategy), (2) no GSS and (3) GSS in symptomatic and asymptomatic MSM. The three testing protocols include testing with nucleic acid amplification test to verify the GSS results in (1) and (3), or as the only test in (2). A transmission model was employed to calculate the influence of the testing strategies on the prevalence of anogenital gonorrhoea over 10 years. An economic model combined cost data on medical consultations, tests and treatment and utility data to estimate the number of epididymitis cases and quality-adjusted life years (QALY) associated with gonorrhoea. Incremental cost-effectiveness ratios (ICERs) for the testing scenarios were estimated. Uncertainty and sensitivity analyses were performed.

RESULTS

No GSS testing compared with GSS in symptomatic MSM only (current strategy) resulted in nine extra epididymitis cases (95% uncertainty interval (UI): 2-22), 72 QALYs lost (95% UI: 59-187) and €7300 additional costs (95% UI: -€185 000 (i.e.cost-saving) to €407 000) over 10 years. GSS testing in both symptomatic and asymptomatic MSM compared with GSS in symptomatic MSM only resulted in one prevented epididymitis case (95% UI: 0-2), 1.1 QALY gained (95% UI: 0.1-3.3), €148 000 additional costs (95% UI: €86 000 to-€217 000) and an ICER of €177 000 (95% UI: €67 000-to €705 000) per QALY gained over 10 years. The results were robust in sensitivity analyses.

CONCLUSIONS

GSS for symptomatic MSM only is cost-effective compared with no GSS for MSM and with GSS for both symptomatic and asymptomatic MSM.

Sexually transmitted infections and HIV RNA levels in blood and anogenital compartments among Thai men who have sex with men before and after antiretroviral therapy: implication for Treatment as Prevention programme

INTRODUCTION

Sexually transmitted infections (STIs) are common among HIV-positive men who have sex with men (MSM). There have been concerns that undiagnosed and untreated STIs could undermine efforts to use antiretroviral therapy (ART) for prevention due to genital secretion infectiousness. We evaluated the correlation between STIs and HIV RNA in anogenital compartments among HIV-positive MSM before and after ART.

METHODS

MSM participants newly diagnosed with HIV were offered ART regardless of CD4 count during November 2012 to November 2015. Syphilis serology, oropharyngeal swab, rectal swab, urine collection for gonorrhoea and chlamydia nucleic acid amplification testing, and HIV RNA measurement in blood, semen and rectal samples were performed at baseline, 12 and 24 months thereafter.

RESULTS

Of 143 HIV-positive MSM, 16.1% had syphilis, 23.1% had gonorrhoea and 32.8% had chlamydia at baseline. Participants with STIs at baseline had higher median HIV RNA levels in blood plasma (p = 0.053), seminal plasma (p = 0.01) and rectal secretions (p = 0.002) than those without STIs. Multivariate models identified HIV RNA 100,000 to 500,000 (OR 6.74, 95% CI 2.24 to 20.28, p = 0.001) and >500,000 (OR 9.39, 95% CI 1.08 to 81.72, p = 0.04) copies/mL in blood, CD4 count <350 cells/mm3 (OR 4.20, 95% CI 1.05 to 16.70, p = 0.04) and having any STIs (OR 2.62, 95% CI 1.01 to 6.80 p = 0.047) to be associated with detectable (>40 copies/mL) seminal plasma HIV RNA. Having chlamydia at any sites (OR 3.17, 95% CI 1.07 to 9.44, p = 0.04) was associated with detectable rectal HIV RNA. Incidences of syphilis, gonorrhoea and chlamydia were 13.4, 16.4 and 18.1 per 100 person-years respectively. Nine participants had detectable HIV RNA (five in blood, one in semen, two in rectal samples and one in both blood and rectal samples) at 12 and/or 24 months after ART.

CONCLUSIONS

STIs were extremely common among HIV-positive MSM prior to and after ART. ART effectively reduced HIV RNA in all compartments. The correlation between STIs and anogenital HIV RNA, especially prior to ART and likely until complete HIV RNA suppression from ART is achieved, points to the importance of integrating asymptomatic STIs screening into Treatment as Prevention programme for MSM.

High-grade anal intraepithelial neoplasia is associated with HIV-1 RNA rectal shedding in virologically suppressed MSM

OBJECTIVE

The protective effect of ART has not yet been definitively established in MSM. We aimed to characterize the factors associated with persistent HIV-1 RNA rectal shedding.

METHODS

Prospective study including virologically suppressed MSM from an HIV cohort. High-resolution anoscopy (HRA) was performed for screening of anal dysplasia, and rectal sampling for HIV-1 RNA quantification and sexually transmitted infections (STIs) investigation through multiplex PCR. Both generalized linear mixed (GLM) and zero-altered negative binomial (ZANB) models were performed.

RESULTS

One hundred and fifty-five rectal swab samples from 132 virologically suppressed MSM were included. HIV-1 RNA was detectable in 61 (39.3%) samples, with median (IQR) rectal viral load (rVL) of 295.8 (158.8-522) copies/swab. Multivariable GLM showed that the presence of high-grade anal intraepithelial neoplasia (HG-AIN; OR 2.85 [95% CI 1.10-7.38]) and a protease inhibitor-based regimen (OR 2.49 [0.98-6.34]) resulted in increased risk for rectal HIV-1 shedding, whereas higher nadir CD4+/CD8+ T-cell ratio (OR 0.18 [0.04-0.93]) was negatively associated with rectal shedding. ZANB analyses showed that the best predictors of having detectable rVL were lower nadir CD4+/CD8+ T-cell ratio (OR 0.98 [0.96-0.99]) and PI-based regimens (OR 4.85 [1.29-18.24]); the presence of HG-AIN (RR 2.50 [1.41-4.45]), and a higher burden of STIs (RR 1.39 [1.03-1.85]) were predictors of rectal HIV-1 shedding intensity.

CONCLUSION

The prevalence of HIV-1 RNA rectal shedding is high in virologically suppressed MSM. In addition to ART and the immune system integrity, local factors, including the co-existence of HG-AIN and the burden of STIs, may account for the persistence of HIV-1 RNA shedding in rectal mucosa.

A Macaque Model for Rectal Lymphogranuloma Venereum and Non-Lymphogranuloma Venereum Chlamydia trachomatis: Impact on Rectal Simian/Human Immunodeficiency Virus Acquisition

BACKGROUND

Sustained genital tract inflammation caused by sexually transmitted infections (STIs) is known to increase risk of vaginal human immunodeficiency virus (HIV) infections but, to our knowledge, there are no nonhuman primate studies that have evaluated its link to rectal HIV acquisition.

METHODS

Rhesus macaques inoculated with Chlamydia trachomatis (CT) (serovars LGV-L2 and CT-E; n = 7) or saline (n = 7) received up to 20 rectal challenges twice a week of simian/HIV immunodeficiency virus (SHIVSF162p3). SHIV viremia was determined by real-time PCR and Chlamydia infection by APTIMA Combo 2 testing. The rectal cytokine-chemokine levels were evaluated by multiplex bead assays.

RESULTS

Rectal Chlamydia infection was maintained throughout the study. We did not observe significant differences (P = 1.0) in frequency of SHIV acquisition between the STI and control arms. It took fewer SHIV challenges to infect the STI animals although the difference was not significant (P = 0.59). There were no significant differences in peak plasma viremia between STI and control arms (P = 0.63). The association of plasma viremia with rectal shedding was significantly different by arm (P = 0.038).

CONCLUSIONS

In the first such study in a macaque model, we did not observe an increased risk of SHIV acquisition due to rectal Chlamydia coinfection. This macaque model can be further developed and expanded to better investigate the impact of different rectal STIs on HIV acquisition.

Condomless Sex Among Virally Suppressed Women With HIV With Regular HIV-Serodiscordant Sexual Partners in the Era of Treatment as Prevention

BACKGROUND

Sexual HIV transmission does not occur with sustained undetectable viral load (VL) on antiretroviral therapy (ART). Awareness of ART prevention benefits and its influence on condom use among women with HIV (WWH) remain unexplored. We estimated prevalence and correlates of condomless sex with regular HIV-serodiscordant partners among WWH with undetectable VL on ART.

METHODS

We used baseline questionnaire data from the community-based longitudinal Canadian HIV Women's Sexual and Reproductive Health Cohort Study (CHIWOS). We included WWH self-reporting vaginal/anal sex with ≥1 HIV-negative/unknown status regular partner within 6 months, and undetectable VL (<50 copies/mL) on ART. We excluded participants exclusively reporting female partners or missing condom-use data. Condomless sex was defined as <100% condom use within 6 months. The primary explanatory variable was awareness of ART prevention benefits. Logistic regression identified factors independently associated with condomless sex.

RESULTS

Of 271 participants (19% of the CHIWOS cohort), median age was 41 (interquartile range: 34-47), 51% were in a relationship, 55% reported condomless sex, and 75% were aware of ART prevention benefits. Among women aware, 63% reported condomless sex compared with 32% of women not aware (P < 0.001). Factors independently associated with condomless sex included being aware of ART prevention benefits (adjusted odds ratio: 4.08; 95% confidence interval: 2.04 to 8.16), white ethnicity, ≥high-school education, residing in British Columbia, and being in a relationship.

CONCLUSIONS

Virally suppressed women aware of ART prevention benefits had 4-fold greater odds of condomless sex. Advancing safer sex discussions beyond condoms is critical to support women in regular serodiscordant partnerships to realize options for safe and satisfying sexuality in the Treatment-as-Prevention era.

Antiretroviral therapy suppresses rectal HIV-RNA shedding despite inflammation in MSM with rectal C. trachomatis and N. gonorrhoeae infections-a cross-sectional, single-center study

OBJECTIVES

Rectal infections with Chlamydia trachomatis and/or Neisseria gonorrhoeae (CT/NG) are common in men who have sex with men (MSM) and are linked to HIV transmission. However, rectal CT/NG infections are often asymptomatic and it is not known how they contribute to HIV transmission. We assessed clinical and cytological signs of inflammation as well as rectal HIV-RNA in HIV-infected MSM with and without CT/NG infection.

METHODS

112 HIV-positive MSM with or without rectal symptoms and with or without antiretroviral therapy who underwent high-resolution anoscopy (HRA) at the proctological outpatient centre of the University Hospital Essen, Germany, between November 2013 and February 2014 were included in this cross-sectional study. During the examination, rectal swabs for the assessment of CT/NG, HIV-RNA and inflammatory cells (granulocytes, lymphocytes, histiocytes) were collected. 110 patients were assessed according to the study protocol, and no imputation of missing data was performed.

RESULTS

Rectal infections with CT or NG were detected in 17 participants, and 4 participants were coinfected. Only symptomatic CT/NG infections (8/17) showed signs of inflammation in HRA. Symptomatic CT/NG infections were also associated with the detection of lymphocytes and histiocytes in rectal cytology (both P<0.001). In contrast, asymptomatic CT/NG infections neither resulted in clinical nor cytological signs of inflammation. Rectal HIV-RNA was undetectable in all participants with rectal CT/NG infections who received combined antiretroviral therapy (ART) when plasma HIV-RNA was below the limit of detection (n=13). Besides rectal CT/NG infections, syphilis (n=4) and HPV-associated lesions (n=37) were frequently detected, and proctological symptoms were associated with simultaneous infection with ≥2 STDs.

CONCLUSIONS

Only symptomatic but not asymptomatic rectal infections with CT and/or NG were associated with clinical and cytological signs of inflammation. Rectal HIV shedding was not promoted by CT/NG infections in patients receiving ART with suppressed plasma HIV-RNA.

TRIAL REGISTRATION NUMBER

UTN: U1111-1150-4804. German Clinical Trials Register (DRKS): DRKS00005468.

HIV Persistence in Gut-Associated Lymphoid Tissues: Pharmacological Challenges and Opportunities

An increasing amount of evidence suggests that HIV replication persists in gut-associated lymphoid tissues (GALT), despite treatment with combination antiretroviral therapy (cART). Residual replication in this compartment may propagate infection at other sites in the body and contribute to sustained immune dysregulation and delayed immune recovery. Therefore, it is important to focus efforts on eliminating residual replication at this site. There are several challenges to accomplishing this goal, including low antiretroviral (ARV) exposure at specific tissue locations within GALT, which might be overcome by using the tools of clinical pharmacology. Here, we summarize the evidence for GALT as a site of residual HIV replication, highlight the consequences of persistent infection in tissues, identify current pharmacologic knowledge of drug exposure in GALT, define the challenges that hinder eradication from this site, and propose several avenues for pharmacologic intervention.

Syphilis on the rise: A prolonged syphilis outbreak among HIV-infected patients in Northern Greece

INTRODUCTION

Sexually transmitted diseases (STDs) are a major public health issue in Europe. Numerous outbreaks of syphilis have been described recently and an increased prevalence of high-risk sexual practices has raised concern about the transmission of HIV and other STDs. Similarly, an increase in sexually transmitted infections has been recorded in Northern Greece.

METHODS

This report describes a recent outbreak of syphilis in people living with HIV. The demographic, clinical, and serologic data of HIV patients diagnosed with syphilis were recorded and analyzed. Data on syphilis incidence from the general population was also compared to HIV patients' data.

RESULTS

Fifty-eight HIV-patients of the Infectious Diseases Unit of a tertiary hospital (5.2%) were diagnosed with syphilis during a three-year period (2008-2010). Highly active antiretroviral therapy (HAART) and coexistence of other STDs were independent predictors of syphilis (OR: 2.4, 95CI%: 1.26, 4.63, p=0.008; OR: 9.4, 95%CI: 4.49, 19.64, p<0.001, respectively). Origin from a country other than Greece (p=0.005), and homosexual contact (p=0.003), were separate risk factors for syphilis in the general population in the same area.

CONCLUSION

Diagnosis of a sexually transmitted disease in an HIV patient is a crucial clinical event that should trigger the clinician's suspicion for high-risk sexual behavior. Sexual health assessments should be a routine process for HIV patients.

Sexual behaviour among people with HIV according to self-reported antiretroviral treatment and viral load status

OBJECTIVE

To assess, among people with HIV, the association of self-reported antiretroviral treatment (ART) and viral load status with condomless sex with an HIV-serodifferent partner (CLS-D).

DESIGN

Cross-sectional study of 3258 HIV-diagnosed adults in the United Kingdom, 2011-2012.

METHODS

CLS-D in the past 3 months and self-reported ART/viral load were ascertained by questionnaire. Clinic-recorded viral load was documented. HIV-transmission risk sex (CLS-D-HIV-risk) was defined as CLS-D together with either not on ART or clinic-recorded viral load more than 50 copies/ml.

RESULTS

Of 3178 participants diagnosed more than 3 months ago, 2746 (87.9%) were on ART, of whom self-reported viral load was '50 copies/ml/ or less/undetectable' for 78.4%; 'more than 50 copies/ml/detectable' for 8.3%; 'do not know/missing' for 13.3%. CLS-D prevalence was 14.9% (326/2189), 6.4% (23/360) and 10.7% (67/629) among men who have sex with men, heterosexual men and women, respectively. Among men who have sex with men, CLS-D prevalence was 18.8% among those not on ART; 15.2% among those on ART with undetectable self-reported viral load; 9.8% among those on ART without undetectable self-reported viral load. Compared with 'on ART with undetectable self-reported viral load', prevalence ratios (95% confidence interval) adjusted for demographic/HIV-related factors were: 0.66 (0.45, 0.95) for 'on ART without undetectable self-reported viral load', and 1.08 (0.78, 1.49) for 'not on ART' (global P = 0.021). Among heterosexual men and women (combined), ART/self-reported viral load was not associated with CLS-D [corresponding adjusted prevalence ratios: 1.14 (0.73, 1.79) for 'on ART without undetectable self-reported viral load'; 0.88 (0.44, 1.77) for 'not on ART', P = 0.77]. CLS-D-HIV-risk prevalence was 3.2% among all participants; 16.1% for 'not on ART'; 0.6% for 'on ART with undetectable self-reported viral load; 4.2% for 'on ART without undetectable self-reported viral load.'

CONCLUSION

Use of ART was not associated with increased prevalence of CLS-D, and was associated with greatly reduced prevalence of HIV-transmission risk sex.

Dispersion of the HIV-1 Epidemic in Men Who Have Sex with Men in the Netherlands: A Combined Mathematical Model and Phylogenetic Analysis

BACKGROUND

The HIV-1 subtype B epidemic amongst men who have sex with men (MSM) is resurgent in many countries despite the widespread use of effective combination antiretroviral therapy (cART). In this combined mathematical and phylogenetic study of observational data, we aimed to find out the extent to which the resurgent epidemic is the result of newly introduced strains or of growth of already circulating strains.

METHODS AND FINDINGS

As of November 2011, the ATHENA observational HIV cohort of all patients in care in the Netherlands since 1996 included HIV-1 subtype B polymerase sequences from 5,852 patients. Patients who were diagnosed between 1981 and 1995 were included in the cohort if they were still alive in 1996. The ten most similar sequences to each ATHENA sequence were selected from the Los Alamos HIV Sequence Database, and a phylogenetic tree was created of a total of 8,320 sequences. Large transmission clusters that included ≥10 ATHENA sequences were selected, with a local support value ≥ 0.9 and median pairwise patristic distance below the fifth percentile of distances in the whole tree. Time-varying reproduction numbers of the large MSM-majority clusters were estimated through mathematical modeling. We identified 106 large transmission clusters, including 3,061 (52%) ATHENA and 652 Los Alamos sequences. Half of the HIV sequences from MSM registered in the cohort in the Netherlands (2,128 of 4,288) were included in 91 large MSM-majority clusters. Strikingly, at least 54 (59%) of these 91 MSM-majority clusters were already circulating before 1996, when cART was introduced, and have persisted to the present. Overall, 1,226 (35%) of the 3,460 diagnoses among MSM since 1996 were found in these 54 long-standing clusters. The reproduction numbers of all large MSM-majority clusters were around the epidemic threshold value of one over the whole study period. A tendency towards higher numbers was visible in recent years, especially in the more recently introduced clusters. The mean age of MSM at diagnosis increased by 0.45 years/year within clusters, but new clusters appeared with lower mean age. Major strengths of this study are the high proportion of HIV-positive MSM with a sequence in this study and the combined application of phylogenetic and modeling approaches. Main limitations are the assumption that the sampled population is representative of the overall HIV-positive population and the assumption that the diagnosis interval distribution is similar between clusters.

CONCLUSIONS

The resurgent HIV epidemic amongst MSM in the Netherlands is driven by several large, persistent, self-sustaining, and, in many cases, growing sub-epidemics shifting towards new generations of MSM. Many of the sub-epidemics have been present since the early epidemic, to which new sub-epidemics are being added.

A Cross Sectional Analysis of Gonococcal and Chlamydial Infections among Men-Who-Have-Sex-with-Men in Cape Town, South Africa

BACKGROUND

Men-who-have-sex-with-men (MSM) are at high risk of HIV and sexually transmitted infection (STI) transmission. Asymptomatic STIs are common in MSM and remain undiagnosed and untreated where syndromic management is advocated. Untreated STIs could be contributing to high HIV rates. This study investigated symptomatic (SSTI) and asymptomatic STIs (ASTIs) in MSM in Cape Town.

METHODS

MSM, 18 years and above, were enrolled into this study. Participants underwent clinical and microbiological screening for STIs. Urine, oro-pharyngeal and anal swab specimens were collected for STI analysis, and blood for HIV and syphilis screening. A psychosocial and sexual questionnaire was completed. STI specimens were analysed for Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) infection.

RESULTS

200 MSM were recruited with a median age of 32 years (IQR 26-39.5). Their median number of sex partners within the last year was 5 (IQR 2-20). 155/200 (78%) reported only male sex partners while 45/200 (23%) reported sex with men and women. 77/200 (39%) reported transactional sex. At enrolment, 88/200 (44%) were HIV positive and 8/112 (7%) initially HIV-negative participants seroconverted during the study. Overall, 47/200 (24%) screened positive for either NG or CT. There were 32 MSM (16%) infected with NG and 7 (3.5%) of these men had NG infections at two anatomical sites (39 NG positive results in total). Likewise, there were 23 MSM (12%) infected with CT and all these men had infections at only one site. Eight of the 47 men (17%) were infected with both NG and CT. ASTI was more common than SSTI irrespective of anatomical site, 38 /200 (19%) versus 9/200 (5%) respectively (p<0.001). The anus was most commonly affected, followed by the oro-pharynx and then urethra. Asymptomatic infection was associated with transgender identity (OR 4.09 CI 1.60-5.62), ≥5 male sex partners in the last year (OR 2.50 CI 1.16-5.62) and transactional sex (OR 2.33 CI 1.13-4.79) but not with HIV infection.

CONCLUSIONS

Asymptomatic STI was common and would not have been detected using a syndromic management approach. Although molecular screening for NG/CT is costly, in our study only four MSM needed to be screened to detect one case. This supports dual NG/CT molecular screening for MSM, which, in the case of confirmed NG infections, may trigger further culture-based investigations to determine gonococcal antimicrobial susceptibility in the current era of multi-drug resistant gonorrhoea.

Anogenital HIV RNA in Thai men who have sex with men in Bangkok during acute HIV infection and after randomization to standard vs. intensified antiretroviral regimens

INTRODUCTION

HIV transmission risk is highest during acute HIV infection (AHI). We evaluated HIV RNA in the anogenital compartment in men who have sex with men (MSM) during AHI and compared time to undetectable HIV RNA after three-drug versus five-drug antiretroviral therapy (ART) to understand risk for onward HIV transmission.

METHODS

MSM with AHI (n=54) had blood, seminal plasma and anal lavage collected for HIV RNA at baseline, days 3 and 7, and weeks 2, 4, 12 and 24. Data were compared between AHI stages: 1 (fourth-generation antigen-antibody combo immunoassay [IA]-, third-generation IA-, n=15), 2 (fourth-generation IA+, third-generation IA-, n=9) and 3 (fourth-generation IA+, third-generation IA+, western blot-/indeterminate, n=30) by randomization to five-drug (tenofovir+emtricitabine+efavirenz+raltegravir+maraviroc, n=18) versus three-drug (tenofovir+emtricitabine+efavirenz, n=18) regimens.

RESULTS

Mean age was 29 years and mean duration since HIV exposure was 15.4 days. Mean baseline HIV RNA was 5.5 in blood, 3.9 in seminal plasma and 2.6 log10 copies/ml in anal lavage (p<0.001). Blood and seminal plasma HIV RNA were higher in AHI Stage 3 compared to Stage 1 (p<0.01). Median time from ART initiation to HIV RNA <50 copies/ml was 60 days in blood, 15 days in seminal plasma and three days in anal lavage. Compared with the three-drug ART, the five-drug ART had a shorter time to HIV RNA <1500 copies/ml in blood (15 vs. 29 days, p=0.005) and <50 copies/ml in seminal plasma (13 vs. 24 days, p=0.048).

CONCLUSIONS

Among MSM with AHI, HIV RNA was highest in blood, followed by seminal plasma and anal lavage. ART rapidly reduced HIV RNA in all compartments, with regimen intensified by raltegravir and maraviroc showing faster HIV RNA reductions in blood and seminal plasma.

The association of uncontrolled HIV infection and other sexually transmitted infections in metropolitan Atlanta youth

BACKGROUND

Half of the 19 million sexually transmitted infections (STIs) and 26% of HIV infections annually in the United States occur in youth aged 13-24 years. STIs are a risk factor for HIV acquisition and transmission, but data are lacking on HIV treatment as an intervention to reduce STIs.

METHODS

A single-centered, retrospective analysis of HIV-infected sexually active adolescents and young adults from January 2009 to December 2011 was performed to compare STI incidence among patients with controlled and uncontrolled HIV and to identify associated risk factors.

RESULTS

Of 205 enrolled subjects, 59% were male and 92% African American with mean age of 21 years (2.1 SD). Sixty-six percent were horizontally infected, and 19% met the definition of controlled HIV. Forty-seven percent were men who have sex with men, 76% reported condom use, 27% prior sexual abuse, 58% drug use and 50% claimed >5 lifetime sexual partners. Sixty-seven percent contracted a co-STI for a cumulative incidence rate of 35 STIs per 100 person-years. Subjects with uncontrolled HIV had a significantly higher STI incidence than did subjects with controlled infection (42.7 vs. 19.7 per 100 person-years, P < 0.001). Uncontrolled individuals had more STIs (P = 0.01), sexual partners (P = 0.008) and horizontal acquisition (P = 0.001). In an adjusted logistic model, having ≥1 STI was associated with older age (P = 0.033), >5 sexual partners (6-10 partners, P = 0.001; >10, P < 0.001) and no condom use (P = 0.025). Subjects with uncontrolled infection had 2.8 times [95% confidence interval (CI): 1.16-6.94] the odds of ≥1 STI relative to controlled HIV.

CONCLUSIONS

Uncontrolled HIV increases the incidence of co-STIs among adolescents and young adults. Interventions to improve antiretroviral compliance and reduce risk behaviors are urgently needed.

The cost-effectiveness of harm reduction

HIV prevalence worldwide among people who inject drugs (PWID) is around 19%. Harm reduction for PWID includes needle-syringe programs (NSPs) and opioid substitution therapy (OST) but often coupled with antiretroviral therapy (ART) for people living with HIV. Numerous studies have examined the effectiveness of each harm reduction strategy. This commentary discusses the evidence of effectiveness of the packages of harm reduction services and their cost-effectiveness with respect to HIV-related outcomes as well as estimate resources required to meet global and regional coverage targets. NSPs have been shown to be safe and very effective in reducing HIV transmission in diverse settings; there are many historical and very recent examples in diverse settings where the absence of, or reduction in, NSPs have resulted in exploding HIV epidemics compared to controlled epidemics with NSP implementation. NSPs are relatively inexpensive to implement and highly cost-effective according to commonly used willingness-to-pay thresholds. There is strong evidence that substitution therapy is effective, reducing the risk of HIV acquisition by 54% on average among PWID. OST is relatively expensive to implement when only HIV outcomes are considered; other societal benefits substantially improve the cost-effectiveness ratios to be highly favourable. Many studies have shown that ART is cost-effective for keeping people alive but there is only weak supportive, but growing evidence, of the additional effectiveness and cost-effectiveness of ART as prevention among PWID. Packages of combined harm reduction approaches are highly likely to be more effective and cost-effective than partial approaches. The coverage of harm reduction programs remains extremely low across the world. The total annual costs of scaling up each of the harm reduction strategies from current coverage levels, by region, to meet WHO guideline coverage targets are high with ART greatest, followed by OST and then NSPs. But scale-up of all three approaches is essential. These interventions can be cost-effective by most thresholds in the short-term and cost-saving in the long-term.

Pharmacokinetics of antiretrovirals in genital secretions and anatomic sites of HIV transmission: implications for HIV prevention

The incidence of HIV remains alarmingly high in many parts of the world. Prophylactic use of antiretrovirals, capable of concentrating in the anatomical sites of transmission, may reduce the risk of infection after an unprotected sexual exposure. To date, orally and topically administered antiretrovirals have exhibited variable success in preventing HIV transmission in large-scale clinical trials. Antiretroviral mucosal pharmacokinetics may help explain the outcomes of these investigations. Penetration and accumulation of antiretrovirals into sites of transmission can influence dosing strategies and pre-exposure prophylaxis clinical trial design. Antiretroviral tissue distribution varies widely within and between drug classes, attributed in part to their physicochemical properties and tissue-specific drug transporter expression. Nucleoside(-tide) reverse transcriptase inhibitors, the CCR5 antagonist maraviroc, and the integrase inhibitor raltegravir demonstrate the highest penetration into the male and female reproductive tracts and colorectal tissue relative to blood. This review describes antiretroviral exposure in anatomic sites of transmission, and places these findings in context with the prevention of HIV and the efficacy of pre-exposure prophylactic strategies.

Trends in reported syphilis and gonorrhea among HIV-infected people in Arizona: implications for prevention and control

OBJECTIVE

HIV and sexually transmitted disease (STD) surveillance patterns in Arizona suggested the need for integrated data analyses to identify trends.

METHODS

We compiled all HIV/AIDS cases diagnosed from 1998 to 2008 that were reported in Arizona and syphilis or gonorrhea cases diagnosed from 1998 to 2008 in Arizona. We used deterministic matching to identify individuals who were diagnosed with HIV and one or more STDs, and calculated time intervals between diagnoses.

RESULTS

Of 23,940 people with HIV/AIDS reported from 1998 to 2008, 1,899 (2.6%) had at least one syphilis or gonorrhea diagnosis from 1998 to 2008. Approximately 85% of these cases reported male-to-male sexual contact. Among males with syphilis, HIV coinfection increased from 0.5% in 1998 to 29.1% in 2008. Among males with gonorrhea, HIV coinfection increased from 2.0% in 1998 to 3.1% in 2008. Among HIV cases diagnosed from 2004 to 2008 and reported with at least one syphilis or gonorrhea diagnosis, the majority of syphilis cases (76.1%) were diagnosed at or after HIV diagnosis, whereas a majority of gonorrhea cases (54.9%) were diagnosed prior to HIV diagnosis.

CONCLUSION

Use of the deterministic matching method identified increases in STD infections among HIV-infected people. The routine performance of this cross-matching method may be a useful tool in identifying these high-risk individuals so that targeted partner services and appropriate care referrals may be used in a timely fashion.

Incorporating couples-based approaches into HIV prevention for gay and bisexual men: opportunities and challenges

Thirty years after the beginning of the HIV epidemic, gay, bisexual, and other men who have sex with men (collectively called MSM) bear a disproportionate burden of HIV in the United States and continue to acquire a distressingly high number and proportion of new infections. Historically, HIV prevention for MSM has been focused on individual-level behavior change, rarely intervening with MSM as part of a couple. Yet, an estimated 33–67% of HIV infections among MSM are acquired from primary sexual partners, suggesting that work with MSM as couples could be an important contributor to prevention. Given the emergence of high impact combination HIV prevention, it is timely to consider how work with the broad variety of male couples can improve both personal and community health. Couples HIV testing and counseling for MSM is an important advance for identifying men who are unaware that they are HIV-positive, identifying HIV-discordant couples, and supporting men who want to learn their HIV status with their partner. Once men know their HIV status, new advances in biomedical prevention, which can dramatically reduce risk of HIV transmission or acquisition, allow men to make prevention decisions that can protect themselves and their partners. This paper highlights the present-day challenges and benefits of using a couples-based approach with MSM in the era of combination prevention to increase knowledge of HIV status, increase identification of HIV discordant couples to improve targeting prevention services,and support mutual disclosure of HIV status.

Modelling the impact of chlamydia screening on the transmission of HIV among men who have sex with men

BACKGROUND

Recent studies have found high prevalences of asymptomatic rectal chlamydia among HIV-infected men who have sex with men (MSM). Chlamydia could increase the infectivity of HIV and the susceptibility to HIV infection. We investigate the role of chlamydia in the spread of HIV among MSM and the possible impact of routine chlamydia screening among HIV-infected MSM at HIV treatment centres on the incidence of chlamydia and HIV in the overall MSM population.

METHODS

A mathematical model was developed to describe the transmission of HIV and chlamydia among MSM. Parameters relating to sexual behaviour were estimated from data from the Amsterdam Cohort Study among MSM. Uncertainty analysis was carried out for model parameters without confident estimates. The effects of different screening strategies for chlamydia were investigated.

RESULTS

Among all new HIV infections in MSM, 15% can be attributed to chlamydia infection. Introduction of routine chlamydia screening every six months among HIV-infected MSM during regular HIV consultations can reduce the incidence of both infections among MSM: after 10 years, the relative percentage reduction in chlamydia incidence would be 15% and in HIV incidence 4%, compared to the current situation. Chlamydia screening is more effective in reducing HIV incidence with more frequent screening and with higher participation of the most risky MSM in the screening program.

CONCLUSIONS

Chlamydia infection could contribute to the transmission of HIV among MSM. Preventive measures reducing chlamydia prevalence, such as routine chlamydia screening of HIV-infected MSM, can result in a decline in the incidence of chlamydia and HIV.

Sexually transmitted infections screening at HIV treatment centers for MSM can be cost-effective

OBJECTIVE

To estimate the cost-effectiveness of anorectal chlamydia screening among men who have sex with men (MSM) in care at HIV treatment centers.

DESIGN

Transmission model combined with economic analysis over a 20-year period.

SETTING AND PARTICIPANTS

MSM in care at HIV treatment centers.

INTERVENTION

Once-yearly or twice-yearly screening for anorectal chlamydia among MSM in care at HIV treatment centers.

MAIN OUTCOME MEASURES

Averted HIV and chlamydia infections; discounted quality-adjusted life-years and costs; incremental cost-effectiveness ratio (ICER).

RESULTS

Costs will be saved by routine chlamydia screening of MSM in care at HIV treatment centers if these patients seek little or no screening elsewhere. Nonroutine screening is considerably more expensive than routine screening offered within a scheduled visit. Adding once-yearly chlamydia screening for MSM in care at HIV treatment centers is cost saving when 30% or fewer of those men seek once-yearly screening elsewhere (1.5 to 8.1 million euro saved). Twice-yearly routine screening at HIV treatment centers is cost-effective only when routine screening takes place without additional nonroutine screening (1.9 million euro saved).

CONCLUSIONS

Adding annual chlamydia screening to the HIV consultation will be cost saving as long as only a limited proportion of men are nonroutinely screened. The ICER was most sensitive to the percentage of MSM that continue to be screened elsewhere.

Overcoming biological, behavioral, and structural vulnerabilities: new directions in research to decrease HIV transmission in men who have sex with men

Men who have sex with men (MSM), including transgender women, comprise a heterogeneous group of individuals whose sexual behaviors and gender identities may vary widely between cultures and among individuals. Their sources of increased vulnerability to HIV are diverse, including the increased efficiency of HIV transmission via unprotected anal intercourse, sexual role versatility, asymptomatic sexually transmitted infections, and behavioral factors that may be associated with condomless sex with multiple partners. Societal stigmatization of homosexual behavior and gender nonconformity may result in internalized negative feelings that lead to depression, other affective disorders, and substance use, which in turn are associated with increased risk-taking behaviors. Social stigma and punitive civil environments may lead to delays in seeking HIV and sexually transmitted disease screening, and later initiation of antiretroviral therapy. The iPrEX study demonstrated that chemoprophylaxis can decrease HIV acquisition in MSM, and the HIV prevention trials network 052 study established the biological plausibility that earlier initiation of highly active antiretroviral therapy can decrease HIV transmission to uninfected partners. Despite these advances, MSM remain among the most significantly HIV-affected population in resource-rich and limited settings. New studies will integrate enhanced understanding of the biology of enhanced rectal transmission of HIV and the focused use of antiretrovirals for prevention with culturally tailored approaches that address the potentiating social and behavioral factors associated with enhanced HIV spread among MSM.

CD4+ T cell count, HIV-1 viral loads and demographic variables of newly identified patients with HIV infection in Wuhan, China

In China, the rate of human immunodeficiency virus (HIV) testing is increasing among men who have sex with men. The purpose of the present study was to describe HIV-related biomarkers and selected demographic variables of persons with newly diagnosed HIV/AIDS, among men who have sex with men in particular, in Wuhan China. Demographic indicators, and CD4+ T cell counts and HIV-1 viral load were collected from individuals newly identified as HIV-1 antibody positive during 2011. Of 176 enrolled patients, 132 (75.0%) were men who have sex with men. This group was significantly younger and had higher CD4+ T cell counts than patients who were likely infected through heterosexual contact. Most men who have sex with men (56.6%) were discovered by initiative investigation. Among heterosexual patients CD4+ T cell counts and HIV-1 viral load were significantly correlated; among the group of men who have sex with men, no such association was found.

The Role of Sexually Transmitted Infections in HIV-1 Progression: A Comprehensive Review of the Literature

Due to shared routes of infection, HIV-infected persons are frequently coinfected with other sexually transmitted infections (STIs). Studies have demonstrated the bidirectional relationships between HIV and several STIs, including herpes simplex virus-2 (HSV-2), hepatitis B and C viruses, human papilloma virus, syphilis, gonorrhea, chlamydia, and trichomonas. HIV-1 may affect the clinical presentation, treatment outcome, and progression of STIs, such as syphilis, HSV-2, and hepatitis B and C viruses. Likewise, the presence of an STI may increase both genital and plasma HIV-1 RNA levels, enhancing the transmissibility of HIV-1, with important public health implications. Regarding the effect of STIs on HIV-1 progression, the most studied interrelationship has been with HIV-1/HSV-2 coinfection, with recent studies showing that antiherpetic medications slow the time to CD4 <200 cells/µL and antiretroviral therapy among coinfected patients. The impact of other chronic STIs (hepatitis B and C) on HIV-1 progression requires further study, but some studies have shown increased mortality rates. Treatable, nonchronic STIs (i.e., syphilis, gonorrhea, chlamydia, and trichomonas) typically have no or transient impacts on plasma HIV RNA levels that resolve with antimicrobial therapy; no long-term effects on outcomes have been shown. Future studies are advocated to continue investigating the complex interplay between HIV-1 and other STIs.

HIV, rectal chlamydia, and rectal gonorrhea in men who have sex with men attending a sexually transmitted disease clinic in a midwestern US city

BACKGROUND

Men who have sex with men (MSM) who report receptive anal intercourse (RAI) are currently recommended to undergo at least annual screening for rectal Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) infection.

METHODS

Using standard culture methods, we assessed the prevalence of rectal GC/CT among MSM who reported RAI in the last year (n = 326) at an urban sexually transmitted disease (STD) clinic in a midwestern US city. A subset (n = 125) also underwent rectal GC/CT screening via nucleic acid amplification testing. We examined the associations between HIV status and prevalence of rectal GC and rectal CT using unadjusted and adjusted logistic regression models.

RESULTS

The prevalence of rectal GC, rectal CT, and either rectal infection was 9%, 9%, and 15% by culture and 24%, 23%, and 38% by nucleic acid amplification testing, respectively. HIV was not associated with rectal GC prevalence in unadjusted or adjusted analyses. HIV-positive status was significantly associated with increased rectal CT prevalence in unadjusted models (odds ratio, 2.18; 95% confidence interval, 1.04-4.60); this association increased after multivariable adjustment (odds ratio, 3.14; 95% confidence interval, 1.37-7.19).

CONCLUSIONS

Men who have sex with men reporting RAI had a high prevalence of rectal GC and rectal CT. HIV-positive status was significantly associated with prevalent rectal CT but not with prevalent rectal GC.

Single- and multiple-dose pharmacokinetics of darunavir plus ritonavir and etravirine in semen and rectal tissue of HIV-negative men

BACKGROUND

Antiretroviral therapy has become a central component of combination in HIV prevention efforts. Defining the individual exposure of commercially available antiretroviral therapy in genital secretions and vulnerable mucosal tissues is paramount to designing future prevention interventions.

METHODS

A pharmacokinetic (PK) study was performed in 12 HIV-negative men receiving 600 mg of darunavir, 100 mg of ritonavir, and 200 mg of etravirine orally, twice daily for 8 days. Seven blood plasma (BP) samples were collected over 12 hours on day 1 (PK1) and days 7 and 8 (PK2). One rectal tissue (RT) sample from each subject was collected during PK1 and PK2. During PK1, 2 seminal plasma (SP) samples were collected from each subject. During PK2, 6 SP samples were collected from each subject over 2 days.

RESULTS

Antiretrovirals were detected in SP and RT within 1 hour after a single dose. Over PK1 and PK2, SP exposures were lower than BP by 80%-92% (DRV), 89-95% (RTV), and 83-88% (ETR). However, protein binding in SP (14% for darunavir, 70% for ritonavir, and 97% for etravirine) was lower than in BP. Rectal tissue exposures were higher than BP by 39- to 155-fold for darunavir, 12- to 61-fold for ritonavir, and 20- to 40-fold for etravirine.

CONCLUSIONS

Lower SP protein binding resulted in higher pharmacologically active darunavir and etravirine concentrations compared with BP. High RT concentrations may also be favorable for suppressing viral replication in the gastrointestinal mucosa. The high protein-unbound exposures in SP and total exposures in RT support further investigations of darunavir plus ritonavir and etravirine in secondary prevention.

Does ART prevent HIV transmission among MSM?

OBJECTIVE

To review the evidence for antiretroviral 'treatment as prevention' for HIV transmission among MSM.

METHODS

We reviewed studies that assess the biological plausibility that virally suppressive antiretroviral therapy (ART) reduces HIV infectiousness via anal intercourse and the epidemiologic evidence of whether ART has played a role in attenuating HIV incidence among MSM.

RESULTS

Although ART treatment among MSM is likely to provide some preventive benefit, it is unknown whether it will reduce HIV infectiousness via anal intercourse to the same extent as via penile-vaginal intercourse. Additional research is needed on the pharmacokinetic properties of specific antiretroviral agents in the gastrointestinal tract. Estimates of risk behaviors and the incidence of HIV among MSM before and after the introduction and expansion of ART suggest that the population-level protective benefits of ART may be attenuated by a number of factors, most notably, continuing or increasing frequency of condomless anal intercourse and incidence of other sexually transmitted infections (STIs). Additional studies are needed on the impact of ART on HIV sexual risk behaviors and transmission among MSM outside of developed countries in North America, western Europe, and Australia.

CONCLUSION

The benefits of treatment as prevention for MSM are highly plausible, but not certain. In the face of these unknowns, treatment guidelines for earlier ART initiation should be considered within a combination prevention strategy that includes earlier diagnosis, expanded STI treatment, and structural and behavioral interventions.

HIV treatment as prevention: natural experiments highlight limits of antiretroviral treatment as HIV prevention

There is growing enthusiasm for increasing coverage of antiretroviral treatment among HIV-infected people for the purposes of preventing ongoing transmission. Treatment as prevention will face a number of barriers when implemented in real world populations, which will likely lead to the effectiveness of this strategy being lower than proposed by optimistic modelling scenarios or ideal clinical trial settings. Some settings, as part of their prevention and treatment strategies, have already attained rates of HIV testing and use of antiretroviral therapy--with high levels of viral suppression--that many countries would aspire to as targets for a treatment-as-prevention strategy. This review examines a number of these "natural experiments", namely, British Columbia, San Francisco, France, and Australia, to provide commentary on whether treatment as prevention has worked in real world populations. This review suggests that the population-level impact of this strategy is likely to be considerably less than as inferred from ideal conditions.