Association of antiretroviral therapy with detection of HIV-1 RNA and DNA in the anorectal mucosa of homosexual men

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.

Stem cell-derived CAR T cells traffic to HIV reservoirs in macaques

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) with CCR5^– donor cells is the only treatment known to cure HIV-1 in patients with underlying malignancy. This is likely due to a donor cell–mediated graft-versus-host effect targeting HIV reservoirs. Allo-HSCT would not be an acceptable therapy for most people living with HIV due to the transplant-related side effects. Chimeric antigen receptor (CAR) immunotherapies specifically traffic to malignant lymphoid tissues (lymphomas) and, in some settings, are able to replace allo-HSCT. Here, we quantified the engraftment of HSC-derived, virus-directed CAR T cells within HIV reservoirs in a macaque model of HIV infection, using potentially novel IHC assays. HSC-derived CAR cells trafficked to and displayed multilineage engraftment within tissue-associated viral reservoirs, persisting for nearly 2 years in lymphoid germinal centers, the brain, and the gastrointestinal tract. Our findings demonstrate that HSC-derived CAR⁺ cells reside long-term and proliferate in numerous tissues relevant for HIV infection and cancer.

Persistent HIV-1 Viremia on Antiretroviral Therapy: Measurement and Mechanisms

HIV-1 viremia persists at low-levels despite clinically effective antiretroviral therapy (ART). Here we review new methods to quantify and characterize persistent viremia at the single genome level, and discuss the mechanisms of persistence including clonal expansion of infected cells and tissue origins of viremia. A deeper understanding of how viremia persists on ART is critically important to the design of therapies to eliminate viremia and achieve a functional cure for HIV-1.

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.

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.

Total HIV-1 DNA, a Marker of Viral Reservoir Dynamics with Clinical Implications

HIV-1 DNA persists in infected cells despite combined antiretroviral therapy (cART), forming viral reservoirs. Recent trials of strategies targeting latent HIV reservoirs have rekindled hopes of curing HIV infection, and reliable markers are thus needed to evaluate viral reservoirs. Total HIV DNA quantification is simple, standardized, sensitive, and reproducible. Total HIV DNA load influences the course of the infection and is therefore clinically relevant. In particular, it is predictive of progression to AIDS and death, independently of HIV RNA load and the CD4 cell count. Baseline total HIV DNA load is predictive of the response to cART. It declines during cART but remains quantifiable, at a level that reflects both the history of infection (HIV RNA zenith, CD4 cell count nadir) and treatment efficacy (residual viremia, cumulative viremia, immune restoration, immune cell activation). Total HIV DNA load in blood is also predictive of the presence and severity of some HIV-1-associated end-organ disorders. It can be useful to guide individual treatment, notably, therapeutic de-escalation. Although it does not distinguish between replication-competent and -defective latent viruses, the total HIV DNA load in blood, tissues, and cells provides insights into HIV pathogenesis, probably because all viral forms participate in host cell activation and HIV pathogenesis. Total HIV DNA is thus a biomarker of HIV reservoirs, which can be defined as all infected cells and tissues containing all forms of HIV persistence that participate in pathogenesis. This participation may occur through the production of new virions, creating new cycles of infection and disseminating infected cells; maintenance or amplification of reservoirs by homeostatic cell proliferation; and viral transcription and synthesis of viral proteins without new virion production. These proteins can induce immune activation, thus participating in the vicious circle of HIV pathogenesis.

Initiation of antiretroviral therapy before detection of colonic infiltration by HIV reduces viral reservoirs, inflammation and immune activation

INTRODUCTION

Colonic infiltration by HIV occurs soon after infection, establishing a persistent viral reservoir and a barrier to cure. We investigated virologic and immunologic correlates of detectable colonic HIV RNA during acute HIV infection (AHI) and their response to antiretroviral treatment (ART).

METHODS

From 49,458 samples screened for HIV, 74 participants were enrolled during AHI and 41 consented to optional sigmoidoscopy, HIV RNA was categorized as detectable (≥50 copies/mg) or undetectable in homogenized colon biopsy specimens. Biomarkers and HIV burden in blood, colon and cerebrospinal fluid were compared between groups and after 24 weeks of ART.

RESULTS

Colonic HIV RNA was detectable in 31 participants (76%) and was associated with longer duration since HIV exposure (median 16 vs. 11 days, p=0.02), higher median plasma levels of cytokines and inflammatory markers (CXCL10 476 vs. 148 pg/mL, p=0.02; TNF-RII 1036 vs. 649 pg/mL, p<0.01; neopterin 2405 vs. 1368 pg/mL, p=0.01) and higher levels of CD8+ T cell activation in the blood (human leukocyte antigen - antigen D related (HLA-DR)/CD38 expression 14.4% vs. 7.6%, p <0.01) and colon (8.9% vs. 4.5%, p=0.01). After 24 weeks of ART, participants with baseline detectable colonic HIV RNA demonstrated persistent elevations in total HIV DNA in colonic mucosal mononuclear cells (CMMCs) (median 61 vs. 0 copies/10(6) CMMCs, p=0.03) and a trend towards higher total HIV DNA in peripheral blood mononuclear cells (PBMC) (41 vs. 1.5 copies/10(6) PBMCs, p=0.06). There were no persistent differences in immune activation and inflammation.

CONCLUSIONS

The presence of detectable colonic HIV RNA at the time of ART initiation during AHI is associated with higher levels of proviral DNA after 24 weeks of treatment. Seeding of HIV in the gut may have long-lasting effects on the size of persistent viral reservoirs and may represent an important therapeutic target in eradication strategies.

Major influence of CD4 count at the initiation of cART on viral and immunological reservoir constitution in HIV-1 infected patients

Background

A persistent immune activation is observed in gut during HIV-1 infection, which is not completely reversed by a combined antiretroviral therapy (cART). The impact of the time of cART initiation may highly influence the size of the viral reservoir and the ratio of CD4⁺/CD8⁺ T cells in the gut. In this study, we analyzed the characteristics of HIV rectal reservoir of long-term treated patients, regarding their blood CD4⁺ T cells count at the time of cART initiation.

Results

Twenty-four consenting men were enrolled: 9 exhibiting a CD4⁺ T cells count >350/mm³ (“high-level CD4 group”) and 15 < 350/mm³ (“low-level CD4 group”) in blood, at the start of cART. An immunophenotypical analysis of T and B cells subpopulations was performed in blood and rectal biopsies. HIV cell-associated DNA loads and qualitative intra-cellular RNA were determined in both compartments. The ratio of CD4⁺/CD8⁺ T cells was significantly decreased in the blood but not in the rectum of the “low-level CD4 group” of patients. The alteration in β7⁺ CD4⁺ T cells homing was higher in this group and was correlated to a low ratio of CD4⁺/CD8⁺ T cells in blood. An initiation of cART in men exhibiting a low-level CD4 count was also associated with an alteration of B cells maturation. HIV blood and gut DNA reservoirs were significantly lower in the “high-level CD4 group” of men. A high HIV DNA level was associated to a detectable intracellular HIV RNA in rectum.

Conclusions

An early initiation of cART could significantly preserve gut immunity and limit the viral reservoir constitution.

Electronic supplementary material

The online version of this article (doi:10.1186/s12977-016-0278-5) contains supplementary material, which is available to authorized users.

The association between HPV, intraepithelial lesions and HIV-1 shedding in anogenital specimens in two contrasting populations: Senegalese women and American MSM

In light of observational evidence showing an association between human papillomavirus (HPV) and HIV acquisition risk, the potential of HPV vaccination as a HIV prevention strategy is being considered. However, the relationship between HPV and HIV infectiousness is unclear. In this analysis, the relationship between HPV and anogenital HIV shedding (a proxy for transmissibility) was assessed in two diverse populations: HIV-infected Senegalese women and American men who have sex with men (MSM). Data from two longitudinal studies with similar protocols were analysed. In both studies, anogenital specimens underwent cytologic, HPV DNA, and HIV-1 RNA testing. Analyses utilised multivariable generalised estimating equations that controlled for age, hormonal contraceptive use (women only), plasma viral load, CD4 count and treatment status. Among Senegalese women, cervical lesions were significantly associated with the detection of HIV RNA (aRR = 1.16 [1.05, 1.28]) and log10 cervicovaginal fluids viral load (adjusted β = 0.56 [0.12, 1.01]). No association was detected between HPV (of any type) and cervicovaginal HIV shedding (aRRDetection = 0.90 [0.77, 1.06]; βQuantity = -0.31 [-0.78, 0.16]). Among MSM, having multiple HPV infections (versus no HPV infection) was associated with anal HIV shedding (aRRDetection = 1.05 [1.01, 1.09]; βQuantity = 0.11 [0.01, 0.21]). Anal lesions were not associated with anal HIV shedding (aRRLESIONS = 0.99 [0.96, 1.03], βLESIONS = -0.05 [-0.13, 0.03]). Although HPV and intraepithelial lesions were associated with anogenital HIV shedding in crude analyses, the measures of effect were attenuated in adjusted analyses. Our data suggest that the prevention of HPV through vaccination is unlikely to substantially affect HIV infectiousness among persons living with HIV.

Antiretrovirals for HIV prevention: when should they be recommended?

Since the introduction of the first antiretroviral agent for HIV treatment, information on antiretroviral therapy (ART) effectiveness has grown continuously. In recent years, there has also been a growth of interest in use of ART for the prevention of HIV transmission, either by reducing the infectivity of the infected person or by protecting the uninfected individuals from HIV acquisition. The purpose of this review is to summarize the body of evidence available for treatment as prevention and pre-exposure prophylaxis and their effectiveness in prevention of infection. In addition, our aim is to discuss the operational aspects of both prevention strategies and to provide commentary for future HIV prevention programs.

The immunological synapse: the gateway to the HIV reservoir

A major challenge in the development of a cure for human immunodeficiency virus (HIV) has been the incomplete understanding of the basic mechanisms underlying HIV persistence during antiretroviral therapy. It is now realized that the establishment of a latently infected reservoir refractory to immune system recognition has thus far hindered eradication efforts. Recent investigation into the innate immune response has shed light on signaling pathways downstream of the immunological synapse critical for T-cell activation and establishment of T-cell memory. This has led to the understanding that the cell-to-cell contacts observed in an immunological synapse that involve the CD4⁺ T cell and antigen-presenting cell or T-cell–T-cell interactions enhance efficient viral spread and facilitate the induction and maintenance of latency in HIV-infected memory T cells. This review focuses on recent work characterizing the immunological synapse and the signaling pathways involved in T-cell activation and gene regulation in the context of HIV persistence.

The HIV-1 reservoir in eight patients on long-term suppressive antiretroviral therapy is stable with few genetic changes over time

The source and dynamics of persistent HIV-1 during long-term combinational antiretroviral therapy (cART) are critical to understanding the barriers to curing HIV-1 infection. To address this issue, we isolated and genetically characterized HIV-1 DNA from naïve and memory T cells from peripheral blood and gut-associated lymphoid tissue (GALT) from eight patients after 4-12 y of suppressive cART. Our detailed analysis of these eight patients indicates that persistent HIV-1 in peripheral blood and GALT is found primarily in memory CD4(+) T cells [CD45RO(+)/CD27((+/-))]. The HIV-1 infection frequency of CD4(+) T cells from peripheral blood and GALT was higher in patients who initiated treatment during chronic compared with acute/early infection, indicating that early initiation of therapy results in lower HIV-1 reservoir size in blood and gut. Phylogenetic analysis revealed an HIV-1 genetic change between RNA sequences isolated before initiation of cART and intracellular HIV-1 sequences from the T-cell subsets after 4-12 y of suppressive cART in four of the eight patients. However, evolutionary rate analyses estimated no greater than three nucleotide substitutions per gene region analyzed during all of the 4-12 y of suppressive therapy. We also identified a clearly replication-incompetent viral sequence in multiple memory T cells in one patient, strongly supporting asynchronous cell replication of a cell containing integrated HIV-1 DNA as the source. This study indicates that persistence of a remarkably stable population of infected memory cells will be the primary barrier to a cure, and, with little evidence of viral replication, this population could be maintained by homeostatic cell proliferation or other processes.

Dolutegravir pharmacokinetics in the genital tract and colorectum of HIV-negative men after single and multiple dosing

OBJECTIVES

To describe first-dose and steady state pharmacokinetics (PKs) of dolutegravir (DTG) in blood plasma (BP), seminal fluid (SF), colorectal tissue (RT), and rectal mucosal fluid (RF) of healthy HIV-negative men.

DESIGN

A phase 1, open-label, PK study that enrolled 12 healthy men taking 50 mg DTG daily for 8 days.

METHODS

Eleven paired BP samples and 3 SF and RF samples were collected over 24 hours after first (PK1) and multiple (PK2) dosing. RT biopsies were collected at 1 of 6 time points at PK1 and PK2 to generate composite PK profiles. DTG concentrations were analyzed by validated liquid chromatography-tandem mass spectrometry (LC-MS/MS). Noncompartmental PK analysis was conducted with Phoenix WinNonlin v6.3, and Spearman rank correlations were determined using SAS v9.3.

RESULTS

BP area under the concentration-time curves (AUCs) were similar to previous reports, and concentrations at 24 hours (C24 h) were 6- to 34-fold greater than the protein-adjusted concentration required for 90% viral inhibition (PA-IC90) of 64 ng/mL. SF exposures were <7% of BP and below the PA-IC90. RT exposures were 17% of BP and ∼2-fold greater than the PA-IC90. RF AUCs were ∼2%-5% of RT and did not correlate with RT (rho = 0.43, P = 0.17). Accumulation of DTG with multiple dosing was observed in BP, SF, and RT.

CONCLUSIONS

DTG BP PKs were consistent with previously published values. SF concentrations were <7% BP, with SF C24 h below the PA-IC90. However, SF protein binding was not measured. Although the AUC of DTG in RT was <20% BP, RT C24 h remained ∼2-fold higher than the PA-IC90. RF was not a strong surrogate for RT concentrations.

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.

Behavioral and biomedical combination strategies for HIV prevention

Around 2.5 million people become infected with HIV each year. This extraordinary toll on human life and public health worldwide will only be reversed with effective prevention. What's more, in the next few years, it is likely at least, that no single prevention strategy will be sufficient to contain the spread of the disease. There is a need for combination prevention as there is for combination treatment, including biomedical, behavioral, and structural interventions. Expanded HIV prevention must be grounded in a systematic analysis of the epidemic's dynamics in local contexts. Although 85% of HIV is transmitted sexually, effective combinations of prevention have been shown for people who inject drugs. Combination prevention should be based on scientifically derived evidence, with input and engagement from local communities that fosters the successful integration of care and treatment.

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

BACKGROUND

Among human immunodeficiency virus (HIV)-infected men who have sex with men (MSM) taking combination antiretroviral therapy (cART), the impact of rectal sexually transmitted infections (STIs) on rectal HIV-1 shedding is unknown.

METHODS

Human immunodeficiency virus type 1 (HIV-1) RNA was quantified from rectal swabs collected for Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT) screening of HIV-1-infected MSM. Correlations of STIs with rectal viral load were explored using multinomial regression modeling. HIV-1 coreceptor tropism was predicted from sequencing in a subset of men.

RESULTS

Thirty-one (39%) of 80 men (59 prescribed combination antiretroviral therapy [cART]) had HIV detected in 38 (42%) of 91 rectal swabs. Rectal HIV detection was associated with plasma virus loads above 3.15 log₁₀ copies/mL (95% confidence limit [CL] 2.73, 3.55) and paired rectal viral loads and plasma viral loads were correlated (Kendall's tau [τ] 0.68, Spearman rho [P] = .77). Rectal STIs and abnormal anal cytology were not associated with rectal viral load. HIV coreceptor distribution was very similar between the plasma and rectum in 3 of 4 men.

CONCLUSIONS

Plasma and rectal viral load were correlated, and rectal STIs did not increase the likelihood of detecting HIV in the rectal secretions in MSM, including those with low or undetectable plasma viral load. Suppressing plasma viral load is likely to reduce risk of HIV transmission to insertive partners.

PCR detection of multiple human herpesvirus DNA in saliva from HIV-infected individuals in Teresina, State of Piauí, Brazil

INTRODUCTION: Human herpesviruses are frequently associated with orofacial diseases in humans (HSV-1, EBV, CMV and HHV-8), some can also cause systemic disease (CMV and HHV-8). The transmission of these viruses occurs by contact with infected secretions, especially saliva. Human immunodeficiency virus infection is associated with an increased risk of HHVs and related diseases. METHODS: This work aimed to detect HSV-1, EBV, CMV and HHV-8 DNA in saliva of HIV-infected patients from Teresina, northeast Brazil, by PCR and compare these findings with age and sex matched HIV-seronegative individuals. RESULTS: No difference in prevalence was verified between HHV detection in the saliva of HIV-seropositive individuals and controls. The individual frequencies of these viruses in these two populations were different. HIV seropositivity correlated positively with the presence of CMV (OR: 18.2, p= 0.00032) and EBV (OR: 3.44, p= 0.0081). No association between CD4 counts and the prevalence of HHVs in the saliva was observed; however, a strong association was determined between seropositivity and the presence of multiple HHV DNAs in saliva (OR: 4.83, p = 0.0028). CONCLUSIONS: These findings suggest the asymptomatic salivary shedding of HHVs is a common event between HIV-seropositive and seronegative individuals from Teresina, Piauí, Brazil, and, especially for HIV-seropositive patients, saliva is a risk factor for the acquisition/transmission of multiple HHVs.

Differences in HIV burden and immune activation within the gut of HIV-positive patients receiving suppressive antiretroviral therapy

BACKGROUND

The gut is a major reservoir for human immunodeficiency virus (HIV) in patients receiving antiretroviral therapy (ART). We hypothesized that distinct immune environments within the gut may support varying levels of HIV.

METHODS

In 8 HIV-1-positive adults who were receiving ART and had CD4(+) T cell counts of >200 cells/μL and plasma viral loads of <40 copies/mL, levels of HIV and T cell activation were measured in blood samples and endoscopic biopsy specimens from the duodenum, ileum, ascending colon, and rectum.

RESULTS

HIV DNA and RNA levels per CD4(+) T cell were higher in all 4 gut sites compared with those in the blood. HIV DNA levels increased from the duodenum to the rectum, whereas the median HIV RNA level peaked in the ileum. HIV DNA levels correlated positively with T cell activation markers in peripheral blood mononuclear cells (PBMCs) but negatively with T cell activation markers in the gut. Multiply spliced RNA was infrequently detected in gut, and ratios of unspliced RNA to DNA were lower in the colon and rectum than in PBMCs, which reflects paradoxically low HIV transcription, given the higher level of T cell activation in the gut.

CONCLUSIONS

HIV DNA and RNA are both concentrated in the gut, but the inverse relationship between HIV DNA levels and T cell activation in the gut and the paradoxically low levels of HIV expression in the large bowel suggest that different processes drive HIV persistence in the blood and gut.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00884793 (PLUS1).

Antiretroviral therapy as HIV prevention: status and prospects

As antiretroviral treatment of HIV infection has become increasingly accessible, attention has focused on whether these drugs can used for prevention because of increased tolerability of newer medications, decreased cost, and the limitations of other approaches. We review the status of antiretroviral HIV prevention, including chemoprophylaxis, as well as the effects of treatment of infected individuals on prevention. It is possible that the life-saving agents that have transformed the natural history of AIDS can be a critical component of HIV prevention efforts, but their ultimate role in affecting HIV transmission dynamics remains to be defined.

Prevention counseling for HIV-infected persons: what every clinician needs to know

The absence of adequate and regular prevention counseling during routine clinical encounters translates into missed opportunities for HIV prevention. HIV care providers have considerably more contact with patients than clinicians in other disciplines. These contacts should be translated into opportunities to provide HIV prevention messages to patients and should be a priority for all clinicians caring for HIV-positive patients. Coincidental preventive care for HIV-positive patients is inherently unproductive because of the absence of reinforcing messages. In a recent meta-analysis, HIV-positive individuals who underwent counseling and testing services reduced high-risk behaviors by about 68%. Prevention counseling should focus on positive reinforcement, harm reduction, education, and support. We strongly recommend regular, brief, targeted prevention counseling as a part of every clinical encounter.

Antiretrovirals to prevent HIV infection: pre- and postexposure prophylaxis

More than 3 million people are now receiving antiretroviral therapy (ART) worldwide. Currently, the indications for ART depend primarily on CD4 count, blood viral burden, and clinical signs and symptoms suggesting advanced HIV disease. However, interest is increasing in ART's preventive potential. Postexposure prophylaxis following both occupational and nonoccupational exposure to HIV is the standard-of-care in many settings. Observational and ecologic studies suggest that ART administered to HIV-infected people reduces transmission within serodiscordant couples. Pre-exposure prophylaxis to prevent HIV infection is a potentially safe and intermittent intervention for very high-risk people, and clinical trials to evaluate this preventive strategy are underway. The prevention benefits of ART may begin to affect the decision of when to start therapy and add a much-needed strategy to current HIV prevention efforts.

Treatment to prevent transmission of HIV-1

Antiretroviral therapy (ART) has the potential to prevent human immunodeficiency virus (HIV) transmission by reducing the concentration of HIV in blood and genital secretions. Indeed, mathematical models with favorable assumptions suggest the potential of ART to stop the spread of HIV infection. Empirical results from ecological and population-based studies and from several short-term observational studies involving HIV status-discordant heterosexual couples suggest that ART reduces the rate of HIV transmission. A multinational, randomized, controlled trial (National Institutes of Health HPTN052) examining the reliability and durability of ART as prevention of transmission in HIV status-discordant couples is under way. The latter and other studies also consider sexual risk-taking behavior and transmission of HIV-resistant variants when ART is used as prevention. Early HIV detection and treatment (ie, test and treat) are being considered as an important prevention strategy. In this article, we review the data supporting the use of ART to prevent HIV transmission and critically examine the public health implications of this strategy.

Discordance in HIV-1 viral loads and antiretroviral drug concentrations comparing semen and blood plasma

OBJECTIVES

For individuals not on antiretroviral therapy, the risk of heterosexual transmission of HIV appears negligible when blood plasma (BP) viral loads are <1500 HIV-1 RNA copies/mL. It is not clear whether this observation can be extrapolated to individuals on highly active antiretroviral therapy (HAART). Because of differential tissue penetration, antiretroviral drug concentrations may be sufficient to maintain an undetectable viral load in the BP yet not achieve adequate levels to suppress HIV in the genital tract. Therefore, we wanted to correlate HIV viral loads and drug concentrations in semen plasma (SP) and BP.

METHODS

Thirty-three men were included. All were on combination antiretroviral therapy with an undetectable BP viral load for at least 1 year. Blood and semen samples were collected within 2 h of each other and tested for HIV RNA by the NucliSens QT (bioMerieux, St Laurent, QC, Canada) method; drug concentrations were determined by liquid chromatography tandem mass spectrometry.

RESULTS

Two of the 33 patients (6.1%) with BP viral loads below detection had time-matched HIV viral loads in SP > or =700 copies/mL. Both patients were on efavirenz, the SP concentrations of which were < or =10% of the levels in BP and well below the minimal therapeutic drug monitoring target concentration required to suppress HIV.

CONCLUSIONS

Because, at least in part, of poor drug penetration into the genital tract, an undetectable HIV viral load in the BP does not guarantee an undetectable viral load in semen. In view of this, caution should be taken in concluding that patients on HAART with suppressed viraemia are sexually non-infectious.

HIV-1 superinfection in the antiretroviral therapy era: are seroconcordant sexual partners at risk?

Background

Acquisition of more than one strain of human immunodeficiency virus type 1 (HIV-1) has been reported to occur both during and after primary infection, but the risks and repercussions of dual and superinfection are incompletely understood. In this study, we evaluated a longitudinal cohort of chronically HIV-infected men who were sexual partners to determine if individuals acquired their partners' viral strains.

Methodology

Our cohort of HIV-positive men consisted of 8 couples that identified themselves as long-term sexual partners. Viral sequences were isolated from each subject and analyzed using phylogenetic methods. In addition, strain-specific PCR allowed us to search for partners' viruses present at low levels. Finally, we used computational algorithms to evaluate for recombination between partners' viral strains.

Principal Findings/Conclusions

All couples had at least one factor associated with increased risk for acquisition of new HIV strains during the study, including detectable plasma viral load, sexually transmitted infections, and unprotected sex. One subject was dually HIV-1 infected, but neither strain corresponded to that of his partner. Three couples' sequences formed monophyletic clusters at the entry visit, with phylogenetic analysis suggesting that one member of the couple had acquired an HIV strain from his identified partner or that both had acquired it from the same source outside their partnership. The 5 remaining couples initially displayed no evidence of dual infection, using phylogenetic analysis and strain-specific PCR. However, in 1 of these couples, further analysis revealed recombinant viral strains with segments of viral genomes in one subject that may have derived from the enrolled partner. Thus, chronically HIV-1 infected individuals may become superinfected with additional HIV strains from their seroconcordant sexual partners. In some cases, HIV-1 superinfection may become apparent when recombinant viral strains are detected.

Longitudinal community plasma HIV-1 RNA concentrations and incidence of HIV-1 among injecting drug users: prospective cohort study

OBJECTIVE

To examine the relation between plasma HIV-1 RNA concentrations in the community and HIV incidence among injecting drug users.

DESIGN

Prospective cohort study.

SETTING

Inner city community in Vancouver, Canada.

PARTICIPANTS

Injecting drug users, with and without HIV, followed up every six months between 1 May 1996 and 30 June 2007.

MAIN OUTCOME MEASURES

Estimated community plasma HIV-1 RNA in the six months before each HIV negative participant's follow-up visit. Associated HIV incidence.

RESULTS

Among 622 injecting drug users with HIV, 12 435 measurements of plasma HIV-1 RNA were obtained. Among 1429 injecting drug users without HIV, there were 155 HIV seroconversions, resulting in an incidence density of 2.49 (95% confidence interval 2.09 to 2.88) per 100 person years. In a Cox model that adjusted for unsafe sexual behaviours and sharing used syringes, the estimated community plasma HIV-1 RNA concentration remained independently associated with the time to HIV seroconversion (hazard ratio 3.32 (1.82 to 6.08, P<0.001), per log(10) increase). When the follow-up period was limited to observations after 1 January 1988 (when the median plasma HIV RNA concentration was <20 000 copies/ml), the median viral load was no longer statistically associated with HIV incidence (1.70 (0.79 to 3.67, P=0.175), per log(10) increase).

CONCLUSIONS

A longitudinal measure of community plasma HIV-1 RNA concentration was correlated with the community HIV incidence rate and predicted HIV incidence independent of unsafe sexual behaviours and sharing used syringes. If these findings are confirmed, they could help to inform both HIV prevention and treatment interventions.

The intestinal mucosa as a reservoir of HIV-1 infection after successful HAART

The presence of HIV-1 RNA in distal duodenal mucosa was evaluated in 44 HIV-1-positive patients. HIV-1 RNA was detected in gut tissue in antiretroviral-naive patients with high plasma viral loads, as well as in patients on HAART with plasma viral loads below the limit of detection and in patients on HAART with virological failure. The intestinal mucosa seems to serve as a reservoir poorly influenced by levels of plasma viral load or HAART.

Unsafe sexual behavior and correlates of risk in a probability sample of men who have sex with men in the era of highly active antiretroviral therapy

OBJECTIVE

To assess the levels and correlates of potential exposure to and transmission of HIV in a contemporary, community-based probability sample of men who have sex with men (MSM).

METHODS

In 2003, 311 sexually active MSM participated in a random-digit dial telephone survey in Seattle neighborhoods with a high prevalence of MSM. The primary outcomes were potential exposure to and transmission of HIV, defined as unprotected anal intercourse with a man of opposite or unknown HIV status in the preceding 12 months.

RESULTS

Fourteen percent of respondents reported being HIV-positive, 77% reported being HIV-negative, and 8% had not been tested. Of 241 HIV-negative MSM, 25 (10%; 95% confidence interval [CI], 7-15%) were potentially exposed to HIV; among 45 HIV-positive MSM, 14 (31%; 95% CI, 20-46%) were potential HIV-transmitters. Among HIV-negative men, the strongest bivariate correlates of potential exposure to HIV were recent bacterial sexually transmitted disease (odds ratio [OR], 5.8), number of recent male sexual partners (OR, 1.01 per partner), recent sex at a bathhouse (OR, 9.1), and recent use of sildenafil (OR, 4.4), amyl nitrite (OR, 6.2), and methamphetamine (OR, 8.0). Among HIV-infected men, the strongest correlates of potential HIV transmission were recent use of amyl nitrite (OR, 3.1), number of recent male sex partners (OR, 1.07 per partner), and having a male spouse or domestic partner (OR, 0.3).

CONCLUSIONS

Most MSM knew their HIV status and adopted safer sexual behaviors to reduce their risk of HIV acquisition or transmission. However, 10% of HIV-negative MSM and 31% of HIV-positive MSM recently engaged in behaviors that placed them at high risk for acquiring or transmitting HIV.

HIV infection and human herpesvirus-8 oral shedding among men who have sex with men

Human herpesvirus-8 (HHV-8) is frequently detected in oropharyngeal secretions from HIV-infected men who have sex with men (MSM), and contact with saliva may be an important mode of HHV-8 transmission. A total of 196 MSM were followed over 2 years to determine the correlates of HHV-8 oropharyngeal shedding. A total of 134 (68%) of 196 participants were HHV-8 seropositive upon enrollment, and 9 (15%) of 62 participants seroconverted to HHV-8 during follow-up. HHV-8 DNA was detected in 43 (22%) of 196 participants: 39 (27%) of 134 HHV-8 seropositive, 4 (8%) of 53 HHV-8 seronegative, and 5 (56%) of 9 seroconverters to HHV-8. HHV-8 was detected in 101 (15%) of 696 total oral specimens: 84 (17%) of 481 samples from HHV-8-seropositive men, 6 (3%) of 180 samples from HHV-8-seronegative men, and 11 (31%) of 35 samples from seroconverters. Using adjusted marginal structural models, HHV-8 shedding was higher in men not receiving highly active antiretroviral therapy (odds ratio 2.4, 95% CI 1.0-6.0, P = 0.06), with CD4 counts > 200 cells/mm (odds ratio 4.8, 95% CI 1.0-22.8, P = 0.05), or with detectable oral leukocyte esterase (odds ratio 5.0, 95% CI 2.0-12.5, P < 0.01). CD4 count, antiretroviral therapy, and oral inflammation may influence HHV-8 oropharyngeal shedding.

Recommendations for incorporating human immunodeficiency virus (HIV) prevention into the medical care of persons living with HIV

The estimated number of annual new human immunodeficiency virus (HIV) infections in the United States has remained at 40,000 for >10 years. Reducing the rate of transmission will require new strategies, including emphasis on prevention of transmission by HIV-infected persons. Medical care providers can affect HIV transmission by screening HIV-infected patients for risk behaviors, communicating prevention messages, discussing sexual and drug-use behaviors, reinforcing changes to safer behavior, referring patients for services such as substance abuse treatment, facilitating partner counseling and referral, and identifying and treating other sexually transmitted diseases. The Centers for Disease Control and Prevention (CDC), the Health Resources and Services Administration (HRSA), the National Institutes of Health (NIH), and the HIV Medicine Association (HIVMA) of the Infectious Diseases Society of America (IDSA) have recently collaborated to develop evidence-based recommendations for incorporating HIV prevention into the medical care of persons living with HIV. This article summarizes key aspects of the recommendations.

Attitudes about combination HIV therapies: the next generation of gay men at risk

This study examined awareness of and attitudes about highly active antiretroviral therapies (HAARTs) among adolescent and young men who have sex with men (MSM). As part of the multisite Young Men's Survey, 813 MSM aged 15-22 years who attended public venues in two cities were questioned about HAART in 1997-1998. Overall, 45.1% had heard of HAART, 61.6% in Seattle, Washington, and 35.0% in New York City. MSM in New York City who were the youngest, men of color, men who were human immunodeficiency virus (HIV) antibody negative, and men who resided in New Jersey were significantly less likely to be aware of HAART. Attitudes about HAART were not associated with sexual risk behaviors. Prevention efforts among young MSM should focus on other determinants of risk, but also include information on the changing nature of HIV therapies.

The intensity-score approach to adjusting for confounding

In a recent article on the efficacy of antihypertensive therapy, Berlowitz et al. (1998, New England Journal of Medicine 339, 1957-1963) introduced an ad hoc method of adjusting for serial confounding assessed via an intensity score, which records cumulative differences over time between therapy actually received and therapy predicted by prior medical history. Outcomes are subsequently regressed on the intensity score and baseline covariates to determine whether intense treatment or exposure predicts a favorable response. We use a structural nested mean model to derive conditions sufficient for interpreting the Berlowitz results causally. We also consider a modified approach that scales the intensity at each time by the inverse expected treatment given prior medical history. This leads to a simple, two-step implementation of G-estimation if we assume a nonstandard but useful structural nested mean model in which subjects less likely to receive treatment are more likely to benefit from it. These modeling assumptions apply, for example, to health services research contexts in which differential access to care is a primary concern. They are also plausible in our analysis of the causal effect of potent antiretroviral therapy on change in CD4 cell count, because men in the sample who are less likely to initiate treatment when baseline CD4 counts are high are more likely to experience large positive changes. We further extend the methods to accomodate repeated outcomes and time-varying effects of time-varying exposures.

Mutational patterns of paired blood and rectal biopsies in HIV-infected patients on HAART

Blood and concurrent rectal biopsy samples of human immunodeficiency virus type 1 (HIV-1)-positive highly active antiretroviral therapy (HAART)-treated patients were tested for genotypic resistance by direct sequencing of reverse transcriptase (RT) and protease (PR) regions to compare the patterns of resistance in these compartments. Fourteen subjects (five with undetectable plasma viral load (pVL) and nine persistently viremic) were studied. Four of five patients with undetectable pVL also had undetectable mucosal HIV RNA; sequence analyses from proviral DNA (PBMCs and rectal biopsy) were obtained with none or few resistance-associated mutations and no alteration of susceptibility profile. All viremic patients, and one with negative pVL, had detectable levels of mucosal HIV RNA (1.93-4.21 log(10) copies/mg); sequences of HIV RNA (plasma and/or rectal biopsy) were also obtained, and multiple mutations generally compatible with current/past medications were detected. Overall, 40 HIV-1 PR and 42 RT sequences were analyzed, yielding a total of 42 PR and 47 RT sequence pairs (plasma/tissue-RNA; plasma-RNA/tissue-DNA; PBMC/tissue-DNA; tissue-DNA/RNA; tissue-RNA/PBMC-DNA; PBMC-DNA/plasma-RNA), which almost always differed at the total amino acid level (median percentage discordance 8.08% in the PR, 4.8% in RT). The median percentage of resistance position discordance equaled 88.8% (IQR = 20-100) in the PR and 74.55% (IQR = 31.75-100%) in the RT pairs, respectively. Different resistance levels were detected by means of a computer-assisted interpretation of mutational profiles. The results support the multiform evolution of HIV genotype in various body compartments and emphasize the participation of intestinal mucosa in HIV genotype selection. Samples from diverse tissues should be used for resistance evaluation to obtain a complete picture of drug resistance for antiretroviral-treated patients.

High prevalence of high risk human papillomavirus-capsid antibodies in human immunodeficiency virus-seropositive men: a serological study

BACKGROUND

Serological study of human papillomavirus (HPV)-antibodies in order to estimate the HPV-prevalence as risk factor for the development of HPV-associated malignancies in human immunodeficiency virus (HIV)-positive men.

METHODS

Sera from 168 HIV-positive men and 330 HIV-negative individuals (including 198 controls) were tested using a direct HPV-ELISA specific to HPV-6, -11, -16, -18, -31 and bovine PV-1 L1-virus-like particles. Serological results were correlated with the presence of HPV-associated lesions, the history of other sexually transmitted diseases (STD) and HIV classification groups.

RESULTS

In HIV-negative men low risk HPV-antibodies were prevailing and associated with condylomatous warts (25.4%). Strikingly, HIV-positive men were more likely to have antibodies to the high-risk HPV types -16, -18, -31, and low risk antibodies were not increased in a comparable range. Even those HIV-positive heterosexual individuals without any HPV-associated lesions exhibited preferentially antibody responses to the oncogenic HPV-types (cumulative 31.1%). The highest antibody detection rate (88,8%) was observed within the subgroup of nine HIV-positive homosexual men with anogenital warts. Three HIV-positive patients had HPV-associated carcinomas, in all of them HPV-16 antibodies were detected. Drug use and mean CD4-cell counts on the day of serologic testing had no influence on HPV-IgG antibody prevalence, as had prior antiretroviral therapy or clinical category of HIV-disease.

CONCLUSION

High risk HPV-antibodies in HIV-infected and homosexual men suggest a continuous exposure to HPV-proteins throughout the course of their HIV infection, reflecting the known increased risk for anogenital malignancies in these populations. The extensive increase of high risk antibodies (compared to low risk antibodies) in HIV-positive patients cannot be explained by differences in exposure history alone, but suggests defects of the immunological control of oncogenic HPV-types. HPV-serology is economic and can detect past or present HPV-infection, independently of an anatomical region. Therefore HPV-serology could help to better understand the natural history of anogenital HPV-infection in HIV-positive men in the era of antiretroviral therapy.

Sexually transmitted diseases and human immunodeficiency virus-discordant partnerships among men who have sex with men

Sexually active men who have sex with men (MSM) at 5 Seattle clinics were assessed for bacterial sexually transmitted diseases (STDs), human immunodeficiency virus (HIV)-discordant partnerships, sexual behavior, and drug use. Of the HIV-positive men, 45% reported having HIV-negative sex partners and 42% reported having sex partners with unknown serostatus during the past 2 months, whereas 14% and 57% of HIV-negative men reported having HIV-positive and unknown-serostatus sex partners, respectively. Correlates of sex partners with unknown serostatus were recruiting sex partners at bathhouses or parks. Gonorrhea, chlamydia, or syphilis was diagnosed in 12% of HIV-positive and 13% of HIV-negative MSM, and the rates did not differ between men with HIV-concordant and HIV-discordant partnerships. High prevalences of bacterial STDs and HIV-discordant partnerships emphasize the need for interventions to foster serostatus discussion, condom use, fewer anonymous partners, and STD screening.

HIV1 and the gut in the era of highly active antiretroviral therapy

The gut and its gut-associated lymphoid tissue serve as a preferential site for HIV1 entry, active viral replication, reservoir, and HIV-mediated CD4 cell apoptosis. The widespread use of highly active antiretroviral therapy (HAART) has resulted in a significant decrease in the incidence of opportunistic enteric pathogens as a consequence of immune recovery. Nonetheless, patients with advanced HIV1 disease who were recently diagnosed or have poor response to HAART can still suffer from opportunistic infections with pathogens such as Cryptosporidium, microsporidia, Isospora belli, Cyclospora cayetanensis, Mycobacterium avium complex, and cytomegalovirus, among others. This review describes the impact of HIV1 infection on gut immune function, the salient features of the most common opportunistic enteric pathogens and HIV-associated enteropathy, and the effects of immune reconstitution after introduction of HAART.

HIV-1 reservoirs

In most infected individuals, HIV-1 replicates high levels throughout the duration of infection, including the clinically quiescent phase of disease. The level of this active viral replication correlates directly with disease progression and survival. The advent of combination therapeutics for HIV-1 (i.e., highly active antiretroviral therapy [HAART]) has led to dramatic reductions in viral replication in vivo and morbidity and mortality, at least in the developed world.

The changing picture of the HIV/AIDS epidemic

Twenty years after it was first recognized, the HIV/AIDS epidemic continues to expand, but its impact varies greatly in different parts of the World. The worst of the epidemic is now centered in developing countries, especially sub-Saharan Africa, and areas such as Eastern Europe, which was only marginally involved a few years ago but has recently experienced the largest growth in the epidemic. In industrialized countries Highly Active Antiretroviral Therapy (HAART) has changed the natural history of HIV/AIDS, causing a reduction in mortality and morbidity due to HIV/AIDS and related diseases. Many interlocking factors determine the impact of HAART at the population level, including reduction of morbidity and mortality, changes in the natural history of HIV/AIDS and associated illnesses, and the effects of HAART on HIV transmission. To fully appreciate the potential benefits of HAART, the epidemic should continue to be monitored in the future, and the effects of HAART on reducing HIV transmission should also be evaluated. Interventions addressed to encourage the adoption of safer sex practices are badly needed, since a "rebound" in risky sexual behaviors was recently reported among high risk groups, which is, at least in part, attributable to the optimism about new treatments.

Sexual risk behaviour relates to the virological and immunological improvements during highly active antiretroviral therapy in HIV-1 infection

OBJECTIVES

To evaluate the effect of highly active antiretroviral therapy (HAART) on the sexual behaviour of homosexual men, we conducted (i) an ecological study of time trends in sexual behaviour and sexually transmitted diseases; (ii) a HAART-effect study focused on the practice of unprotected anogenital sex.

DESIGN

Subjects were participants in the ongoing Amsterdam Cohort Studies (ACS) among homosexual men, initiated in 1984. Data for (i) represented all ACS visits by HIV-1-positive and -negative participants who entered ACS at or below 30 years of age and were followed until 35 years (n = 1062). Data for (ii) represented all ACS visits of HIV-1-positive men from 1992 to 2000 (n = 365), of whom 84 were HAART recipients with at least 2 months of behavioural follow-up.

RESULTS

(i) After HAART became generally available in July 1996, unprotected sex was practised more frequently and the incidence of gonorrhoea was higher compared to March 1992-June 1996 among HIV-1-negative and -positive men, respectively. (ii) Among HIV-1-positive men, a higher level of unprotected sex with casual partners was observed after HIV-1 RNA became undetectable and CD4 cell counts increased with the use of HAART. Notably, in individuals who did not receive HAART, high HIV-1-RNA levels (above 10(5) copies/ml) were likewise related to unprotected sex with casual partners.

CONCLUSION

Data support the need for the reinforcement of safe sex prevention messages among HIV-1-negative men, and our data also provide a lead for redirecting and tailoring current prevention strategies to the needs of HIV-1-positive men.