Sustained Undetectable Viral Load Research Articles

The Potential Role of Undetectable = Untransmittable (U = U) in Reducing HIV Stigma among Sexual Minority Men in the US.

The Undetectable = Untransmittable (U = U) message and its scientific underpinnings have been widely suggested to reduce HIV stigma. However, misunderstanding and skepticism about U = U may prevent this destigmatizing potential from being fully realized. This cross-sectional study examined associations between U = U belief (belief that someone with a sustained undetectable viral load has zero risk of sexually transmitting HIV) and HIV stigma among US sexual minority men. Differences by serostatus and effects of brief informational messaging were also explored. The survey was completed online by 106 men living with HIV and 351 HIV-negative/status-unknown men (2019-2020). Participants were 18-83 years old (M[SD] = 41[13.0]). Most were non-Hispanic White (70.0%) and gay (82.9%). Although nearly all participants (95.6%) were aware of U = U, only 41.1% believed U = U. A greater percentage of participants living with HIV (66.0%) believed U = U compared with HIV-negative/status-unknown participants (33.6%). Among participants living with HIV, U = U belief was not significantly associated with perceived, internalized, or experienced HIV stigma or with viral load prejudice (prejudice against people who have a detectable HIV viral load). Among HIV-negative/status-unknown participants, U = U belief was associated with less frequently enacted HIV discrimination, more positive feelings toward people with an undetectable viral load, and lower personal endorsement of stigmatizing beliefs. Brief informational messaging about U = U did not affect most stigma dimensions and did not favorably affect any. Interventions are needed to correct commonly held, outdated misconceptions about HIV transmission risk. Such initiatives must not only engage people living with HIV but also engage HIV-negative/status-unknown people to maximize the destigmatizing potential of U = U.

Long-term success for people living with HIV: A framework to guide practice.

In recent decades, the needs of people living with HIV have evolved as life expectancy has greatly improved. Now, a new definition of long-term success (LTS) is necessary to help address the multifaceted needs of all people living with HIV. We conducted a two-phase research programme to delineate the range of experiences of people living with HIV. The insights garnered from these research phases were explored in a series of expert-led workshops, which led to the development and refinement of the LTS framework. The insights generated from the research phases identified a series of themes that form a part of LTS. These themes were subsequently incorporated into the LTS framework, which includes five outcome pillars: sustained undetectable viral load, minimal impact of treatment and clinical monitoring, optimized health-related quality of life, lifelong integration of healthcare, and freedom from stigma and discrimination. A series of supporting statements were also developed by the expert panel to help in the achievement of each of the LTS pillars. The LTS framework offers a comprehensive and person-centric approach that, if achieved, could help improve the long-term well-being of people living with HIV and support the LTS vision of 'every person living with HIV being able to live their best life'.

Experiences of recently HIV-diagnosed gay and bisexual migrants in Australia: Implications for sexual health programmes and health promotion.

Gay and bisexual migrants from low- and middle-income countries living in high-income countries are disproportionately diagnosed with HIV. Most research focuses on preventing HIV acquisition among HIV-negative migrant gay and bisexual men (GBM). This study is uniquely positioned to report on migrant GBM's experiences and needs at and after an HIV diagnosis. Semi-structured interviews were conducted with 24 migrant GBM diagnosed at sexual health clinics in Australia from 2017 onwards. Interviews were analysed using a codebook thematic analysis. Due to the stigma of HIV and homosexuality in their countries of origin, about half of participants had poor HIV knowledge prior to diagnosis. Absorbing diagnosis information was consequently difficult, and feelings of shame, hopelessness, lost sexual opportunities and infectiousness were common. However, many were thankful for the comprehensive clinical support they received and believed that over time life would 'normalise' with sustained undetectable viral load. None reported that their clinician stigmatised them, but the anticipation of stigma nonetheless infused their experiences after diagnosis. Many were selective about HIV disclosure, and some mentioned that clinic systems posed a risk to confidentiality. Non-permanent residents were concerned about the impacts of HIV status on future visa applications. We recommend that newly HIV-diagnosed migrant GBM receive referral to legal and culturally appropriate migration services to help absorb what a diagnosis might mean for their health and visa status. We also recommend sexual health clinics continue to assess confidentiality in their systems. Health promotion initiatives should highlight to migrant GBM that high-HIV caseload sexual health clinicians provide confidential and comprehensive care.

Outcomes of the Treatment with Glecaprevir/Pibrentasvir following heart transplantation utilizing hepatitis C viremic donors.

The use of direct-acting antivirals (DAA) has expanded transplantation from hepatitis C viremic donors (HCV-VIR). Our team has conducted an open-label, prospective trial to assess outcomes transplanting HCV viremic hearts. Glecaprevir/pibrentasvir (GLE/PIB) was our sole DAA. Serial quantitative hepatitis C virus (HCV) RNA PCR was obtained to assess HCV viral titers. Between January 2018 and June 2019, a total of 50 recipients were transplanted. Of these, 22/50 (44%) were from HCV-VIR, the remaining 28 from non-viremic (HCV NON-VIR) donors. An 8-week course of GLE/PIB was initiated at 1week post-transplant. There was no difference in demographic or clinical parameters between groups. All 22 recipients of HCV-VIR transplants became viremic. GLE/PIB was effective in decreasing viremia to undetectable levels by 6weeks post-transplant in all patients. The median time to first undetectable HCV quantitative PCR was (4.3weeks, IQR: 4-5.7weeks). All patients demonstrated sustained undetectable viral load through 1-year follow-up. There was no difference in survival at one year between HCV NON-VIR 28/28: (100%) vs HCV-VIR 21/22 (95%) recipients. Our center reports excellent outcomes in transplanting utilizing hearts from HCV-VIR donors. No effect on survival or co-morbidity was found. An 8-week GLE/PIB course was safe and effective when initiated approximately 1week post-transplant.

Sexual Anxiety Among Women Living with HIV in the Era of Antiretroviral Treatment Suppressing HIV Transmission

Sustained undetectable viral loads (UDVLs) on antiretroviral therapy (ART) eliminate sexual HIV transmission. We measured prevalence and correlates of sexual anxiety among women living with HIV. We used questionnaire data collected between August 2013 and May 2015 from 1422 women ≥ 16 years in the Canadian HIV Women’s Sexual and Reproductive Health Cohort Study. Among women reporting consensual sex in the past month (n = 474), we determined the proportion who reported high anxiety (“always/usually became anxious or inhibited during sexual activity with a partner”), low anxiety (“sometimes/seldom”), and no anxiety. Logistic regression identified medical, psychological, relational, and social correlates, including awareness of ART prevention benefits (i.e., “makes the risk of transmitting HIV a lot lower”). Cohort diversity is reflected in age (range 17–66; median 39), gender (5.7% trans), ethnicity (41.6% White, 24.5% Indigenous, 27.0% African/Caribbean/Black), sexual orientation (14.2% lesbian/queer), and time living with HIV (range 18 days–30 years.). Overall, 58.6% reported feeling no sexual anxiety, while the remainder said that they always/usually (14.6%) or sometimes/seldom (26.8%) became anxious or inhibited during sex. Current sex work, previous illicit drug use, and depression were associated with higher adjusted odds of sexual anxiety, while greater emotional closeness and more equitable relationship power were associated with lower odds. There was no correlation between awareness of ART prevention benefits and sexual anxiety. Relatively few women reported high anxiety during sex with a partner. This was more socially and relationally influenced than linked to understanding ART prevention benefits. Women living with HIV should be supported to have great sex, free from worry, by tackling unequal power in women’s intimate relationships, lack of access to resources, and mental health difficulties.

Post-traumatic Stress Disorder, Cocaine Use, and HIV Persistence.

Post-traumatic stress disorder (PTSD) and stimulant use disorders are highly prevalent, commonly co-occur, and predict faster clinical HIV progression. However, scant research has examined if PTSD and cocaine use are associated with the HIV reservoir that persists in immune cells, lymphoid tissue, and organs of people living with HIV that are receiving effective treatment. This cross-sectional study enrolled 48 HIV-positive persons with sustained undetectable viral load (< 20 copies/mL) in the past year to examine the associations of PTSD and recent cocaine use with two measures of HIV persistence in immune cells: (1) proviral HIV DNA and (2) cell-associated (CA)-HIV RNA. Greater PTSD symptoms were significantly associated with lower proviral HIV DNA (r= - 0.30, p= 0.041) but not with CA-HIV RNA. Greater severity of PTSD symptom clusters for intrusions (Standardized Beta = - 0.30, p= 0.038) and hyperarousal (Standardized Beta = - 0.30, p= 0.047) were independently associated with lower proviral HIV DNA. Although participants with recent cocaine use had a significantly shorter duration of sustained undetectable HIV viral load (19.9 versus 26.9months; p= 0.047), cocaine use was not significantly associated with proviral HIV DNA or CA-HIV RNA. Further research is needed to examine the potentially bi-directional pathways linking PTSD symptom severity and HIV persistence.

MON-030 AUTO-IMMUNE PHENOMENA IN TREATED HIV - A RARE CASE OF ANCA VASCULITIS

Anti-neutrophil cytoplasmic antibody (ANCA) positivity has been reported in up to 8% of people living with the human immune-deficiency virus (HIV) (PLHIV). Despite the prevalence of serologic ANCA positivity, it is rarely associated with vasculitis and organ-specific disease in this population. Here we present a rare case of ANCA positivity with a clinical syndrome of rapidly progressive glomerulonephritis (RPGN) and histology proven pauci-immune necrotizing glomerulonephritis (GN). Here we present a rare case of ANCA-associated vasculitis and RPGN in a patient with longstanding, treated HIV. A 69-year-old male presented to a local teaching hospital with 4 weeks of dry cough, dyspnoea and coryzal symptoms. HIV infection had been diagnosed 11 years prior. His most recent bloods showed a normal CD4 count and a sustained undetectable viral load on long-term highly active anti-retroviral therapy (HAART). In February 2017 his creatinine was 86umol/L. At presentation in March 2018, his CD4 count was 0.14 x 10^9/L (0.56 - 1.58) with an undetectable viral load. He was hypoxic with bilateral crackles and had a creatinine of 441umol/L, pANCA + with MPO titre >740 CU (<20) and diffuse bilateral infiltrates on CXR consistent with pulmonary haemorrhage. Renal ultrasound showed normal sized kidneys with no evidence of obstruction or chronic kidney disease. Renal biopsy confirmed pauci-immune necrotizing GN with 10% cellular crescents and no evidence of chronic renal disease. Immunofluorescence demonstrated focal mesangial positivity for C3 in the glomeruli. The diagnosis of MPO-ANCA-associated microscopic polyangiitis was made. The patient was treated with haemodialysis, plasma exchange, steroids and cyclophosphamide with azathioprine maintenance. After 3 months, he showed evidence of renal recovery and ceased dialysis. His creatinine at 7 months was 218umol/L with MPO-ANCA titre in the normal range. Disease remission was demonstrated with standard immuno-suppressive therapy and at 7 months follow-up he remained free from infective complications and had not compromised control of his HIV. Other authors have described auto-immune disease (AD) occurring in PLHIV and have successfully treated these patients with standard immuno-suppressive therapy. Yen et al. (2017) found PLHIV being treated with HAART demonstrated an increased risk of psoriasis, auto-immune haemolytic anaemia and uveitis. Evans et al. (2014) reported a case of ANCA-associated vasculitis and pauci-immune GN in HIV which responded to immuno-suppressive therapy without infective complications or flare of HIV. ANCA associated vasculitis and RPGN presentations are rare in PLHIV. Improved therapies and follow-up for PLHIV may contribute to increasing numbers of patients living with well-controlled HIV who remain at risk of AD in the setting of chronic immune dysregulation.

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

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. 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. 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. 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.

First-line cART regimen impacts the course of CD8+ T-cell counts in HIV-infected patients that achieve sustained undetectable viral load.

The aim of the study was to investigate the impact of first-line combined antiretroviral therapy (cART) regimen on the course of CD8 T-cell counts in human immunodeficiency virus (HIV)-infected patients.A retrospective observational study conducted on the French DAT'AIDS Cohort of HIV-infected patients.We selected 605 patients initiating a first-line cART between 2002 and 2009, and which achieved a sustained undetectable HIV plasma viral load (pVL) for at least 12 months without cART modification. The evolution of CD8 T-cell counts according to cART regimen was assessed.CD8 T-cell counts were assessed in 572 patients treated with 2NRTIs+1PI/r (n= 297), 2NRTIs+1NNRTI (n= 207) and 3NRTIs (n= 68). In multivariate analysis, after 12 months of follow-up, the 3NRTIs regimen was associated with a significantly smaller decrease of CD8 T-cell count compared with NNRTI-containing regimens (-10.2 cells/μL in 3NRTIs vs -105.1 cells/μL; P=0.02) but not compared with PI-containing regimens (10.2 vs -60.9 cells/μL; P=0.21). After 24 months, the 3NRTIs regimen was associated with a smaller decrease of CD8 T-cell count and % compared with PI/r- and NNRTI-containing regimens (0.2 in 3NRTIs vs -9.9 with PI/r-regimens, P=0.001, and vs -11.1 with NNRTI-regimens, p < 0.0001). A focus analysis on 11 patients treated with an INSTI-containing cART regimen during the study period showed after 12 months of follow-up, a median decrease of CD8 T-cell count of -155 [inter quartile range: -302; -22] cells/μL.Our data highlight the fact that cART regimens have differential effects on CD8 pool down regulation.

Sexual risk behaviour among people living with HIV according to the biomedical risk of transmission: results from the ANRS-VESPA2 survey.

IntroductionPeople living with HIV (PLHIV) on antiretroviral therapy (ART), with sustained undetectable viral load (sUVL) and no history of sexually transmitted infections for at least six months, are considered to have a low risk of HIV transmission (LRT). We aimed to characterize, in a representative sample of French PLHIV, the sexual behaviour of LRT PLHIV compared with non-LRT PLHIV.MethodsThe cross-sectional ANRS-VESPA2 survey was conducted on adult PLHIV attending French hospitals in 2011. The LRT PLHIV group included participants with sUVL and no sexually transmitted infection for at least 12 months. Socio-behavioural and medical data were collected. Chi-square tests helped compare sexual risk indicators between LRT and non-LRT PLHIV. The survey's retrospective nature allowed us to perform complementary category-based analyses of LRT PLHIV according to whether they had sUVL for at least 18, 24 or 36 months in three socio-epidemiological groups: men who have sex with men (MSM), other men and women.ResultsAnalysis included 2638 PLHIV diagnosed >12 months with available viral load data. The proportion of LRT PLHIV varied from 58% (≥12 months sUVL) to 38% (≥36 months sUVL). Irrespective of sUVL duration, we found the following: 1) LRT men (MSM and other men) were more likely to report having no sexual partner than their non-LRT counterparts. Among men having sexual partners in the previous 12 months, no significant difference was seen between LRT and non-LRT men in the number of sexual partners. LRT women were less likely to report having more than one sexual partner than non-LRT women; 2) LRT MSM were more likely to report being in sexually inactive couples than their non-LRT counterparts; 3) among sexually active participants, no difference was observed between LRT and non-LRT PLHIV concerning condom use with their serodiscordant steady partner or with their most recent casual sexual partners.ConclusionsLRT PLHIV with sUVL ≥12 months did not report more sexual risk behaviours than their non-LRT counterparts. Because the same result was obtained for those having a sUVL ≥36 months, the hypothesis of increased sexual risk behaviour over time in PLHIV meeting non-transmission biomedical criteria is not supported.

Impact of hepatitis C virus coinfection on T-cell dynamics in long-term HIV-suppressors under combined antiretroviral therapy.

The objective of this study is to evaluate the impact of hepatitis C virus (HCV) serostatus on the evolution of CD8 cells and CD4 : CD8 ratio in HIV-infected patients on combined antiretroviral therapy (cART) who achieve sustained undetectable viral load (HIV-pVL). A longitudinal study performed in an outpatient HIV-unit following 1495 HIV-infected patients. Data of patients on cART achieving undetectable HIV-pVL for at least 3 years were collected retrospectively from our medical e-database NADIS from January 1997 to April 2005, a period defined in order to select patients who were naive of hepatitis treatment. T-cell counts were assessed every 6 months from HIV-suppression over the study period. Two hundred and twenty-six HIV mono-infected (group 1) and 130 HCV-coinfected patients (group 2; genotype prevalence: 42% HCV-G1, 26% HCV-G3, 11% HCV-G4 and 21% HCV-G2) fulfilled the selection criteria. cART regimens were comparable between the groups, as were CD4 and CD8 cell counts at the first undetectable HIV-pVL. After 3 years, both groups displayed similar CD4 cell reconstitution, although CD4 percentage was higher in group 1 (30.3 ± 1.1 vs. 27 ± 1.1%; P < 0.001). HIV suppression led to a significant drop of median CD8 cell counts in group 1 (P = 0.027), but not in group 2, which displayed higher CD8 cell counts all through the follow-up (mean diff. = 135.71 ± 26.89 cells/μl, P < 0.001). Moreover, the fraction of patients reaching CD4 : CD8 ratio ≥ 1 was lower in group 2 (14 vs. 27.7%; P < 0.05). Despite sustained HIV suppression under cART, HCV coinfection was found to hamper CD8 downregulation. Further studies will determine the impact of treatment with direct-acting antiviral agents on the CD8 pool, and the advantage of systematic HCV-targeted therapy for HIV/HCV-coinfected patients.

“Payment by Results”—Financial Incentives and Motivational Interviewing, Adherence Interventions in Young Adults with Perinatally Acquired HIV-1 Infection: A Pilot Program

Emerging evidence suggests financial incentives (FIs) improve medication adherence in select populations. A small proportion of adolescents with perinatal HIV (PaHIV) transfer to adult services with established poor adherence and advanced disease. We describe a single center adherence intervention combining FIs with motivational interviewing (MI). Eligible patients (PaHIV,16-25 years, CD4 count ≤ 200, off ART despite multiple attempts) received MI, and FI dependent on viral load (VL) reduction for 1 year. Outcome measures compared CD4 gain from baseline at 1 year and 12 months post cessation of FI/MI. Eleven young people enrolled; median age 19 years, 8 female. Baseline median CD4 count 30 cells/μL (IQR 10-160), VL 12,870 c/mL. Outcomes at 12 months: 9/11 ever achieved VL < 50, 5 sustained undetectable VL, median CD4 140, mean CD4 gain 90 cells/μL at 1 year. Twelve months post cessation of MI/FI; six VL < 50, median CD4 75, mean CD4 gain 122 cells/μL. Total FI expenditure £1,350: £68 per 50 CD4 cells at 1 year, £55 at 24 months. To prevent death, adolescents with PaHIV require novel interventions to reverse poor patterns of adherence established since childhood. FI/MI improved virological and immunological outcomes with minimal expenditure. Extension of this pilot work for vulnerable individuals is now indicated.

Désir d’enfant et VIH : le préservatif est-il dépassé ?

With antiretroviral therapy, the risk of HIV transmission from an infected person to a stable heterosexual partner is very low when a sustained undetectable viral load is achieved, in the absence of associated genital tract infections. However, epidemiological data do not prove that there is no risk at all. Virological data confirm that when the blood viral load is undetectable for several months, the viral load in semen usually becomes undetectable, but viral shedding can persist in some cases. Two different issues are involved: 1): Can we do without assisted reproductive in HIV sero-different couples who want to have a child? and; 2): can couples in which one or both members are HIV positive entirely stop using condoms? The current French guidelines consider natural conception to be a reasonable option for these couples, recommending self-insemination when the woman is HIV positive and timed unprotected intercourse when the man is HIV positive. Preconceptional care should be available, including viral load monitoring, detection of genital infections and an estimation of the couple's potential fertility. On the other hand, we must strongly discourage unprotected sex in high-risk situations. The best prevention of risk behavior is to offer complete information and appropriate support to people with HIV who wish to conceive.

Becoming a "Treatment Success": What Helps and What Hinders Patients from Achieving and Sustaining Undetectable Viral Loads

Highly active antiretroviral therapy (HAART) adherence research has focused predominantly on individuals with less than optimal clinical outcomes; therefore, little is known about the experiences of individuals who sustain undetectable viral loads. The present study used a qualitative method to explore how individuals who have sustained undetectable viral loads account for their success, and to identify challenges, as well as possible needs, for continued success. Participants were 20 patients at an outpatient infectious disease clinic in an urban center. Participants completed two 60-minute interviews. The Critical Incident Technique was used to identify and classify critical incidents linked with sustaining treatment success. Of the 438 critical incidents collected, 316 were identified as helpful and 122 were identified as unhelpful. Helpful categories included resolving ambivalence, using personal strengths, and fostering helpful relationships. Unhelpful categories were mood, lack of social support, financial difficulties, and medication factors. Doing well on antiretroviral therapy is a dynamic process that requires ongoing attention from both the patient and care provider. The results of this study highlight the efforts of patients to maintain their health and remind care providers not to assume that patients are not facing continuous challenges. Findings from the present study suggest that psychosocial factors do contribute to improved clinical outcomes in patients taking HAART.

Persistence of distinct HIV-1 populations in blood monocytes and naive and memory CD4 T cells during prolonged suppressive HAART

Reservoirs of HIV-1 are a major obstacle to virus eradication. There is therefore a need to clearly understand the molecular nature of the virus populations that persist in patients with sustained suppression of plasma viraemia on highly active antiretroviral therapy (HAART). We performed a detailed analysis of the genotypes of HIV-1 quasispecies isolated from highly purified blood cell types taken from three selected patients with sustained undetectable viral loads on HAART for 7 years. We used polychromatic flow cytometry to sort naive and memory CD4 T cells, CD14 monocytes, and CD56+CD3- natural killer (NK) cells from the total peripheral blood mononuclear cells after 7 years of HAART. Clonal analysis was used to determine coreceptor use and drug-resistance genotypes of HIV-1 quasispecies in the sorted blood cell types. We detected HIV-1 DNA in memory and naive CD4 T cells and in CD14 monocytes, but not in the CD56+CD3- NK cells. Phylogenetic analysis demonstrated that the various blood cells types of two of the three patients harboured genetically distinct HIV-1 quasispecies. Drug-resistance mutations were also distributed differently from one cell type to another. This compartmentalization suggests a minimal virus trafficking between blood cell types during suppressive HAART. We observed a cell-specific compartmentalization of the residual virus populations during prolonged suppressive HAART. The coexistence of numerous HIV-1 quasispecies with different resistance genotypes and coreceptor use in cellular reservoirs may be relevant for future antiretroviral treatment strategies.

British HIV Association (BHIVA) guidelines for the treatment of HIV‐infected adults with antiretroviral therapy (2005)

British HIV Association (BHIVA) guidelines for the treatment of HIV‐infected adults with antiretroviral therapy (2005)

Modeling the long-term control of viremia in HIV-1 infected patients treated with antiretroviral therapy

Highly active antiretroviral therapy (HAART), administered to a HAART-naı̈ve patient, perturbs the steady state of chronic infection. This perturbation provides an opportunity to investigate the existence and dynamics of different sources of viral production. Models of HIV dynamics can be used to make a comparative analysis of the efficacies of different drug regimens. When HAART is administered for long periods of time, most patients achieve ‘undetectable’ viral loads (VLs), i.e., below 50 copies/ml. Use of an ultrasensitive VL assay demonstrates that some of these patients obtain a low steady state VL in the range 5–50 copies/ml, while others continue to exhibit VL declines to below 5 copies/ml. Interestingly, when patients exhibit continued declines below 50 copies/ml the virus has a half-life of ∼6 months, consistent with some estimates of the rate of latent cell decline. Some patients, despite having sustained undetectable VLs, show periods of transient viremia (blips). We present a statistical characterization of the blips observed in a set of 123 patients, suggesting that patients have different tendencies to show blips during the period of VL suppression, that intermittent episodes of viremia have common amplitude profiles, and that VL decay from the peak of a blip may have two phases.