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1.  Nondisclosure of HIV Status in a Clinical Trial Setting: Antiretroviral Drug Screening Can Help Distinguish Between Newly Diagnosed and Previously Diagnosed HIV Infection 
In The HIV Prevention Trials Network 061 study, 155 human immunodeficiency virus (HIV)–infected men reported no prior HIV diagnosis; 83 of those men had HIV RNA levels of <1000 copies/mL at enrollment. Antiretroviral drug testing revealed that 65 of the 83 (78.3%) men were on antiretroviral treatment. Antiretroviral drug testing can help distinguish between newly diagnosed and previously diagnosed HIV infection.
PMCID: PMC3864502  PMID: 24092804
HIV; antiretroviral; self-report; MSM; new diagnosis
2.  Undisclosed Antiretroviral Drug Use in a Multinational Clinical Trial (HIV Prevention Trials Network 052) 
The Journal of Infectious Diseases  2013;208(10):1624-1628.
The HIV Prevention Trials Network 052 study enrolled serodiscordant couples. Index participants infected with human immunodeficiency virus reported no prior antiretroviral (ARV) treatment at enrollment. ARV drug testing was performed retrospectively using enrollment samples from a subset of index participants. ARV drugs were detected in 45 of 96 participants (46.9%) with an undetectable viral load, 2 of 48 (4.2%) with a low viral load, and 1 of 65 (1.5%) with a high viral load (P < .0001); they were also detected in follow-up samples from participants who were not receiving study-administered treatment. ARV drug testing may be useful in addition to self-report of ARV drug use in some clinical trial settings.
PMCID: PMC3805242  PMID: 23908493
HIV; antiretroviral drug; self-report; HPTN 052; Africa; clinical trial
3.  Cross-Sectional HIV Incidence Estimation in HIV Prevention Research 
Accurate methods for estimating HIV incidence from cross-sectional samples would have great utility in prevention research. This report describes recent improvements in cross-sectional methods that significantly improve their accuracy. These improvements are based on the use of multiple biomarkers to identify recent HIV infections. These multi-assay algorithms (MAAs) use assays in a hierarchical approach for testing that minimizes the effort and cost of incidence estimation. These MAAs do not require mathematical adjustments for accurate estimation of the incidence rates in study populations in the year prior to sample collection. MAAs provide a practical, accurate, and cost-effective approach for cross-sectional HIV incidence estimation that can be used for HIV prevention research and global epidemic monitoring.
PMCID: PMC3737594  PMID: 23764641
HIV; incidence; cross-sectional; multi-assay algorithm
4.  HIV Diversity as a Biomarker for HIV Incidence Estimation: Including a High-Resolution Melting Diversity Assay in a Multiassay Algorithm 
Journal of Clinical Microbiology  2014;52(1):115-121.
Multiassay algorithms (MAAs) can be used to estimate cross-sectional HIV incidence. We previously identified a robust MAA that includes the BED capture enzyme immunoassay (BED-CEIA), the Bio-Rad Avidity assay, viral load, and CD4 cell count. In this report, we evaluated MAAs that include a high-resolution melting (HRM) diversity assay that does not require sequencing. HRM scores were determined for eight regions of the HIV genome (2 in gag, 1 in pol, and 5 in env). The MAAs that were evaluated included the BED-CEIA, the Bio-Rad Avidity assay, viral load, and the HRM diversity assay, using HRM scores from different regions and a range of region-specific HRM diversity assay cutoffs. The performance characteristics based on the proportion of samples that were classified as MAA positive by duration of infection were determined for each MAA, including the mean window period. The cross-sectional incidence estimates obtained using optimized MAAs were compared to longitudinal incidence estimates for three cohorts in the United States. The performance of the HRM-based MAA was nearly identical to that of the MAA that included CD4 cell count. The HRM-based MAA had a mean window period of 154 days and provided cross-sectional incidence estimates that were similar to those based on cohort follow-up. HIV diversity is a useful biomarker for estimating HIV incidence. MAAs that include the HRM diversity assay can provide accurate HIV incidence estimates using stored blood plasma or serum samples without a requirement for CD4 cell count data.
PMCID: PMC3911463  PMID: 24153134
5.  Use of a Multifaceted Approach to Analyze HIV Incidence in a Cohort Study of Women in the United States: HIV Prevention Trials Network 064 Study 
The Journal of Infectious Diseases  2012;207(2):223-231.
Background. Reliable methods for estimating the incidence of human immunodeficiency virus (HIV) infection are needed to monitor the epidemic, identify at-risk populations, and evaluate HIV prevention strategies. We used a multifaceted approach to estimate HIV incidence in the HIV Prevention Trials Network (HPTN) 064 study.
Methods. The HPTN 064 study enrolled 2067 HIV-seronegative women and 32 HIV-seropositive women with no prior HIV infection diagnosis. Women were followed for up to 12 months. HIV incidence estimates were based on (1) detection of acute HIV infection, (2) documentation of HIV seroconversion, and (3) detection of recent HIV infection, using a multiassay algorithm (MAA).
Results. Two women had acute HIV infection at enrollment, 4 seroconverted, and 2 were identified as recently infected at enrollment using the MAA. The annual HIV incidence estimate based on acute infection at enrollment (2.52% [95% confidence interval {CI}, .17%–9.33%], using a 14-day window period) was higher than the estimate based on seroconversion (0.24% [95% CI, .07%–.62%]; P = .027). Incidence estimates obtained using the MAA at enrollment and at the end of study were 0.25% (95% CI, .03%–.93%) and 0.13% (95% CI, .006%–.76%), respectively.
Conclusions. We detected a high frequency of acute infection at enrollment. Cross-sectional HIV incidence estimates obtained using the MAA were similar to the longitudinal estimate based on HIV seroconversion.
Clinical Trials Registration. NCT00995176.
PMCID: PMC3532822  PMID: 23129758
HIV-1; women; United States; incidence
6.  HIV Type 1 Polymerase Gene Polymorphisms Are Associated With Phenotypic Differences in Replication Capacity and Disease Progression 
Background. Determinants of intersubtype differences in human immunodeficiency virus type 1 (HIV-1) clinical disease progression remain unknown.
Methods. HIV-1 subtype was independently determined for 5 separate genomic regions in 396 HIV-1 seroconverters from Rakai, Uganda, using a multiregion hybridization assay. Replication capacities (RC) in samples from a subset of 145 of these subjects were determined. HIV-1 genomic regions and pol RC were examined for association with disease progression. Amino acid polymorphisms were examined for association with pol RC.
Results. In multivariate analyses, the hazard for progression to the composite end point (defined as a CD4+ T-cell count <250 cells/mm3, antiretroviral therapy initiation, or death) among patients with subtype D pol infection was 2.4 times the hazard for those infected with subtype A pol infection (P = .001). Compared with subtype A pol (the reference group), the hazard for progression to the composite end point for subtype D pol infection with a pol RC >67% (ie, the median pol RC) was significantly greater (HR, 4.6; 95% confidence interval [CI], 1.9–11.0; P = .001), whereas the hazard for progression to the composite end point for subtype D pol infection with a pol RC ≤67% was not significantly different (HR, 2.2; 95% CI, 1.0–4.9; P = .051). Amino acid substitutions at protease positions 62 and 64 and at reverse transcriptase position 272 were associated with significant differences in pol RC.
Conclusions. HIV-1 pol gene intersubtype and RC differences are associated with disease progression and may be influenced by amino acid polymorphisms.
PMCID: PMC3864385  PMID: 23922373
HIV-1 Subtype; subtype A; subtype D; disease progression; polymerase; replication capacity; amino acid polymorphisms
7.  Pharmacokinetics and Safety of Tenofovir in HIV-infected Women during Labor and their Infants During the First Week of Life 
Data describing the pharmacokinetics and safety of tenofovir in neonates are lacking.
HPTN 057 was a phase 1, open label study of the pharmacokinetics and safety of tenofovir disoproxil fumarate (TDF) in HIV infected women during labor and their infants during the first week of life with 4 dosing cohorts: maternal 600 mg doses/no infant dosing; no maternal dosing/infant 4 mg/kg doses day 0, 3 and 5; maternal 900 mg doses/infant 6 mg/kg doses day 0, 3 and 5; maternal 600 mg doses/infant 6 mg/kg doses daily ×7 doses. Pharmacokinetic sampling was performed on cohort 1 and 3 mothers and all infants. Plasma, amniotic fluid and breast milk tenofovir concentrations were determined by liquid chromatographic – tandem mass spectrometric assay. The pharmacokinetic target was for infant tenofovir concentration throughout the first week of life to exceed 50 ng/mL, the median trough tenofovir concentration in adults receiving standard chronic TDF dosing.
122 mother-infant pairs from Malawi and Brazil were studied. Tenofovir exposure in mothers receiving 600 mg and 900 mg exceeded that in non-pregnant adults receiving standard 300 mg doses. Tenofovir elimination in the infants was equivalent to that in older children and adults and trough tenofovir plasma concentrations exceeded 50 ng/mL in 74–97% of infants receiving daily dosing.
A TDF dosing regimen of 600 mg during labor and daily infant doses of 6 mg/kg maintains infant tenofovir plasma concentration above 50 ng/mL throughout the first week of life and should be used in studies of TDF efficacy for HIV PMTCT and early infant treatment.
PMCID: PMC3912736  PMID: 23979002
tenofovir; neonate; pharmacokinetics
8.  Effects of early versus delayed initiation of antiretroviral treatment on clinical outcomes of HIV-1 infection: results from the phase 3 HPTN 052 randomised controlled trial 
The Lancet. Infectious diseases  2014;14(4):281-290.
Use of antiretroviral treatment for HIV-1 infection has decreased AIDS-related morbidity and mortality and prevents sexual transmission of HIV-1. However, the best time to initiate antiretroviral treatment to reduce progression of HIV-1 infection or non-AIDS clinical events is unknown. We reported previously that early antiretroviral treatment reduced HIV-1 transmission by 96%. We aimed to compare the effects of early and delayed initiation of antiretroviral treatment on clinical outcomes.
The HPTN 052 trial is a randomised controlled trial done at 13 sites in nine countries. We enrolled HIV-1-serodiscordant couples to the study and randomly allocated them to either early or delayed antiretroviral treatment by use of permuted block randomisation, stratified by site. Random assignment was unblinded. The HIV-1-infected member of every couple initiated antiretroviral treatment either on entry into the study (early treatment group) or after a decline in CD4 count or with onset of an AIDS-related illness (delayed treatment group). Primary events were AIDS clinical events (WHO stage 4 HIV-1 disease, tuberculosis, and severe bacterial infections) and the following serious medical conditions unrelated to AIDS: serious cardiovascular or vascular disease, serious liver disease, end-stage renal disease, new-onset diabetes mellitus, and non-AIDS malignant disease. Analysis was by intention-to-treat. This trial is registered with, number NCT00074581.
1763 people with HIV-1 infection and a serodiscordant partner were enrolled in the study; 886 were assigned early antiretroviral treatment and 877 to the delayed treatment group (two individuals were excluded from this group after randomisation). Median CD4 counts at randomisation were 442 (IQR 373–522) cells per μL in patients assigned to the early treatment group and 428 (357–522) cells per μL in those allocated delayed antiretroviral treatment. In the delayed group, antiretroviral treatment was initiated at a median CD4 count of 230 (IQR 197–249) cells per μL. Primary clinical events were reported in 57 individuals assigned to early treatment initiation versus 77 people allocated to delayed antiretroviral treatment (hazard ratio 0·73, 95% CI 0·52–1·03; p=0·074). New-onset AIDS events were recorded in 40 participants assigned to early antiretroviral treatment versus 61 allocated delayed initiation (0·64, 0·43–0·96; p=0·031), tuberculosis developed in 17 versus 34 patients, respectively (0·49, 0·28–0·89, p=0·018), and primary non-AIDS events were rare (12 in the early group vs nine with delayed treatment). In total, 498 primary and secondary outcomes occurred in the early treatment group (incidence 24·9 per 100 person-years, 95% CI 22·5–27·5) versus 585 in the delayed treatment group (29·2 per 100 person-years, 26·5–32·1; p=0·025). 26 people died, 11 who were allocated to early antiretroviral treatment and 15 who were assigned to the delayed treatment group.
Early initiation of antiretroviral treatment delayed the time to AIDS events and decreased the incidence of primary and secondary outcomes. The clinical benefits recorded, combined with the striking reduction in HIV-1 transmission risk previously reported, provides strong support for earlier initiation of antiretroviral treatment.
US National Institute of Allergy and Infectious Diseases.
PMCID: PMC4144040  PMID: 24602844
9.  Analysis of Genetic Linkage of HIV From Couples Enrolled in the HIV Prevention Trials Network 052 Trial 
The Journal of Infectious Diseases  2011;204(12):1918-1926.
Background. The HIV Prevention Trials Network (HPTN) 052 trial demonstrated that early initiation of antiretroviral therapy (ART) reduces human immunodeficiency virus (HIV) transmission from HIV-infected adults (index participants) to their HIV-uninfected sexual partners. We analyzed HIV from 38 index-partner pairs and 80 unrelated index participants (controls) to assess the linkage of seroconversion events.
Methods. Linkage was assessed using phylogenetic analysis of HIV pol sequences and Bayesian analysis of genetic distances between pol sequences from index-partner pairs and controls. Selected samples were also analyzed using next-generation sequencing (env region).
Results. In 29 of the 38 (76.3%) cases analyzed, the index was the likely source of the partner’s HIV infection (linked). In 7 cases (18.4%), the partner was most likely infected from a source other than the index participant (unlinked). In 2 cases (5.3%), linkage status could not be definitively established.
Conclusions. Nearly one-fifth of the seroconversion events in HPTN 052 were unlinked. The association of early ART and reduced HIV transmission was stronger when the analysis included only linked events. This underscores the importance of assessing the genetic linkage of HIV seroconversion events in HIV prevention studies involving serodiscordant couples.
PMCID: PMC3209811  PMID: 21990420
10.  Effect of community-based voluntary counselling and testing on HIV incidence and social and behavioural outcomes (NIMH Project Accept; HPTN 043): a cluster-randomised trial 
The lancet global health  2014;2(5):e267-e277.
NIMH Project Accept (HPTN 043) was a cluster-randomized trial that tested whether a multicomponent, multi-level prevention strategy (community-based voluntary counselling and testing [CBVCT]) reduced HIV incidence compared to standard voluntary counselling and testing (SVCT).
Forty-eight communities were enrolled at five sites in South Africa, Tanzania, Zimbabwe, and Thailand. CBVCT was designed to make testing more accessible in communities, engage communities through outreach, and provide post-test support services. SVCT comprised standard VCT services established at existing facilities. Communities were randomized in matched pairs to 36 months of CBVCT or SVCT. Data were collected at baseline (n=14,567) and post-intervention (n=56,683) by cross-sectional random surveys of 18–32 year-old community residents. HIV incidence was estimated using a cross-sectional multi-assay algorithm. Thailand was excluded from incidence analyses due to low HIV prevalence.
The estimated incidence in the CBVCT was 1.52% vs. 1.81% in the SVCT with an estimated reduction in HIV incidence of 13·9% (relative risk [RR]=0·86; 95% confidence interval [CI]=0·725–1·023; p=0·08). Women older than 24 years had RR=0·70 (95% CI=0·54–0·90; p=0·009). CBVCT increased testing rates by 25% overall (95% CI=12%–39%; p=0·0003), by 45% among men and 15% among women. No overall effect on sexual risk behaviour was observed. However, among HIV-infected participants, CBVCT reduced the number of sexual partners by 8% (95% CI=1%–15%; p=0.03) and the proportion of multiple partnerships by 30% (95% CI=8%-46%; p=0.01). Social norms regarding HIV testing were improved in CBVCT communities.
The intervention was effective in increasing HIV testing, particularly among men, promoted positive social norms regarding testing, and reduced behavioural risk among HIV-infected participants. A modest reduction in HIV incidence was observed. This intervention focused primarily on HIV detection. Current and future studies that include strategies for HIV treatment and viral suppression should demonstrate further incidence reductions.
PMCID: PMC4131207  PMID: 25103167
HIV; incidence; Project Accept; Africa; HPTN 043
11.  Differential Specificity of HIV Incidence Assays in HIV Subtypes A and D-Infected Individuals from Rakai, Uganda 
AIDS Research and Human Retroviruses  2013;29(8):1146-1150.
Assays to determine HIV incidence from cross-sectional surveys have exhibited a high rate of false-recent misclassification in Kenya and Uganda where HIV subtypes A and D predominate. Samples from individuals infected with HIV for at least 2 years with known infecting subtype (133 subtype A, 373 subtype D) were tested using the BED-CEIA and an avidity assay. Both assays had a higher rate of false-recent misclassification for subtype D compared to subtype A (13.7% vs. 6.0%, p=0.02 for BED-CEIA; 11.0% vs. 1.5%, p<0.001 for avidity). For subtype D samples, false-recent misclassification by the BED-CEIA was also more frequent in women than men (15.0% vs. 5.6%, p=0.002), and for samples where that had an amino acid other than lysine at position 12 in the BED-CEIA peptide coding region (p=0.002). Furthermore in subtype D-infected individuals, samples misclassified by one assay were 3.5 times more likely to be misclassified by the other assay. Differential misclassification by infecting subtype of long-term infected individuals as recently infected makes it difficult to use these assays individually to estimate population level incidence without precise knowledge of the distribution of these subtypes within populations where subtype A and D cocirculate. The association of misclassification of the BED-CEIA with the avidity assay in subtype D-infected individuals limits the utility of using these assays in combination within this population.
PMCID: PMC3715796  PMID: 23641870
12.  A Comparison of Two Measures of HIV Diversity in Multi-Assay Algorithms for HIV Incidence Estimation 
PLoS ONE  2014;9(6):e101043.
Multi-assay algorithms (MAAs) can be used to estimate HIV incidence in cross-sectional surveys. We compared the performance of two MAAs that use HIV diversity as one of four biomarkers for analysis of HIV incidence.
Both MAAs included two serologic assays (LAg-Avidity assay and BioRad-Avidity assay), HIV viral load, and an HIV diversity assay. HIV diversity was quantified using either a high resolution melting (HRM) diversity assay that does not require HIV sequencing (HRM score for a 239 base pair env region) or sequence ambiguity (the percentage of ambiguous bases in a 1,302 base pair pol region). Samples were classified as MAA positive (likely from individuals with recent HIV infection) if they met the criteria for all of the assays in the MAA. The following performance characteristics were assessed: (1) the proportion of samples classified as MAA positive as a function of duration of infection, (2) the mean window period, (3) the shadow (the time period before sample collection that is being assessed by the MAA), and (4) the accuracy of cross-sectional incidence estimates for three cohort studies.
The proportion of samples classified as MAA positive as a function of duration of infection was nearly identical for the two MAAs. The mean window period was 141 days for the HRM-based MAA and 131 days for the sequence ambiguity-based MAA. The shadows for both MAAs were <1 year. Both MAAs provided cross-sectional HIV incidence estimates that were very similar to longitudinal incidence estimates based on HIV seroconversion.
MAAs that include the LAg-Avidity assay, the BioRad-Avidity assay, HIV viral load, and HIV diversity can provide accurate HIV incidence estimates. Sequence ambiguity measures obtained using a commercially-available HIV genotyping system can be used as an alternative to HRM scores in MAAs for cross-sectional HIV incidence estimation.
PMCID: PMC4072769  PMID: 24968135
13.  Nucleoside Reverse Transcriptase Inhibitor Resistance Mutations Associated with First-Line Stavudine-Containing Antiretroviral Therapy: Programmatic Implications for Countries Phasing Out Stavudine 
The Journal of Infectious Diseases  2013;207(Suppl 2):S70-S77.
The World Health Organization Antiretroviral Treatment Guidelines recommend phasing-out stavudine because of its risk of long-term toxicity. There are two mutational pathways of stavudine resistance with different implications for zidovudine and tenofovir cross-resistance, the primary candidates for replacing stavudine. However, because resistance testing is rarely available in resource-limited settings, it is critical to identify the cross-resistance patterns associated with first-line stavudine failure.
We analyzed HIV-1 resistance mutations following first-line stavudine failure from 35 publications comprising 1,825 individuals. We also assessed the influence of concomitant nevirapine vs. efavirenz, therapy duration, and HIV-1 subtype on the proportions of mutations associated with zidovudine vs. tenofovir cross-resistance.
Mutations with preferential zidovudine activity, K65R or K70E, occurred in 5.3% of individuals. Mutations with preferential tenofovir activity, ≥two thymidine analog mutations (TAMs) or Q151M, occurred in 22% of individuals. Nevirapine increased the risk of TAMs, K65R, and Q151M. Longer therapy increased the risk of TAMs and Q151M but not K65R. Subtype C and CRF01_AE increased the risk of K65R, but only CRF01_AE increased the risk of K65R without Q151M.
Regardless of concomitant nevirapine vs. efavirenz, therapy duration, or subtype, tenofovir was more likely than zidovudine to retain antiviral activity following first-line d4T therapy.
PMCID: PMC3657117  PMID: 23687292
HIV-1; drug resistance; mutations; nucleoside reverse transcriptase inhibitor; NRTI; stavudine; d4T; zidovudine; AZT; tenofovir; TDF; subtypes
14.  HIV Acquisition Among Women From Selected Areas of the United States 
Annals of internal medicine  2013;158(1):10-18.
Women account for 23% of newly diagnosed HIV infections in the United States, but there are few recent, well-characterized cohorts of U.S. women in whom behavior characteristics and HIV acquisition have been well-described.
To evaluate HIV incidence and describe behaviors among U.S. women residing in areas of high HIV prevalence.
Multisite, longitudinal cohort of women who had HIV rapid testing and audio computer-assisted self-interviews at baseline and every 6 months for up to 12 months. ( NCT00995176)
10 urban and periurban communities with high HIV prevalence and poverty rates, located in the northeastern and southeastern United States.
Venue-based sampling was used to recruit women aged 18 to 44 years who recently had unprotected sex and had 1 or more additional personal or partner risk factors and no self-reported previous HIV diagnosis.
HIV prevalence and incidence, frequency of HIV risk behaviors, and health status perceptions.
Among 2099 high-risk women (85.9% black and 11.7% of Hispanic ethnicity), 32 (1.5%) were diagnosed with HIV infection at enrollment. Annual HIV incidence was 0.32% (95% CI, 0.14% to 0.74%). Older age, substance use, and knowing a partner had HIV were associated with HIV prevalence. Ten women died during the study (0.61% per year).
Longitudinal assessment of risk behaviors was limited to a maximum of 12 months. There were few incident HIV infections, precluding identification of characteristics predictive of HIV acquisition.
This study enrolled a cohort of women with HIV incidence substantially higher than the Centers for Disease Control and Prevention national estimate in the general population of U.S. black women. Concerted efforts to improve preventive health care strategies for HIV and overall health status are needed for similar populations.
PMCID: PMC4033695  PMID: 23277896
15.  Impact of Maternal and Infant Antiretroviral Drug Regimens on Drug Resistance in HIV-Infected Breastfeeding Infants 
The Pediatric infectious disease journal  2013;32(4):10.1097/INF.0b013e31827f44ee.
The HPTN 046 trial evaluated the efficacy of extended infant nevirapine (NVP) administration for prevention of HIV transmission through breastfeeding. Infants received daily NVP to 6 weeks of age. HIV-uninfected infants (the intent-to-treat group) received daily NVP or placebo up to 6 months of age. We analyzed emergence of NVP resistance in infants who acquired HIV-infection despite prophylaxis.
HIV genotyping was performed using the ViroSeq HIV Genotyping System. Medians and proportions were used to summarize data. Two-sided Fisher’s exact tests were used to evaluate associations between categorical variables.
NVP resistance was detected in 12 (92.3%) of 13 infants who were HIV-infected by 6 weeks and in seven (28%) of 25 infants who were HIV-uninfected at 6 weeks and HIV-infected at 6 months of age (6/8=75% in the NVP arm, 1/17=5.9% in the placebo arm, P=0.001). Among those 25 infants, 4 had mothers who initiated an antiretroviral (ARV) treatment regimen by 6 months postpartum. In all 4 cases, the treatment regimen included a non-nucleoside reverse transcriptase inhibitor (NVP or efavirenz). NVP resistance was detected in all four of those infants by 6 months of age (4/4=100%). In contrast, only three (14.2%) of the remaining 21 HIV-infected infants whose mothers did not initiate ARV treatment developed NVP resistance (P=0.003).
Extended NVP prophylaxis significantly increased the risk of NVP resistance in infants who acquired HIV infection after 6 weeks of age. Treatment of maternal HIV infection was also associated with emergence of NVP resistance in HIV-infected, breastfed infants.
PMCID: PMC3826537  PMID: 23249916
Nevirapine resistance; prevention of mother-to-child transmission; extended nevirapine; HIV
16.  Emergence and persistence of nevirapine (NVP) resistance in breast milk after single-dose NVP administration 
AIDS (London, England)  2010;24(4):557-561.
Single-dose nevirapine (sdNVP) can reduce the risk of HIV vertical transmission. We assessed risk factors for NVP resistance in plasma and breast milk from sdNVP-exposed Ugandan women.
Samples were analyzed using the Roche AMPLICOR HIV-1 Monitor Test Kit, v1.5, and the ViroSeq HIV-1 Genotyping System. NVP concentrations were determined by liquid chromatography with tandem mass spectroscopy.
HIV genotypes (plasma and breast milk) were obtained for 30 women 4 weeks after sdNVP (HIV subtypes: 15A, 1C, 12D, 2 recombinant). NVP resistance was detected in 12 (40%) of 30 breast milk samples. There was a non-significant trend between detection of NVP resistance in breast milk and plasma (p=0.06). There was no association of HIV resistance in breast milk with median maternal pre-NVP viral load or CD4 cell count, median breast milk viral load at 4 weeks, breast milk sodium >10 mmol/L, HIV subtype, or concentration of NVP in breast milk or plasma.
NVP resistance was frequently detected in breast milk 4 weeks after sdNVP exposure. In this study, we were unable to identify specific factors associated with breast milk NVP resistance.
PMCID: PMC3065236  PMID: 20057308
nevirapine; HIV-1; breast milk; Uganda; vertical transmission; nevirapine resistance
17.  Estimation of HIV Incidence Using Multiple Biomarkers 
American Journal of Epidemiology  2013;177(3):264-272.
The incidence of human immunodeficiency virus (HIV) is the rate at which new HIV infections occur in populations. The development of accurate, practical, and cost-effective approaches to estimation of HIV incidence is a priority among researchers in HIV surveillance because of limitations with existing methods. In this paper, we develop methods for estimating HIV incidence rates using multiple biomarkers in biological samples collected from a cross-sectional survey. An advantage of the method is that it does not require longitudinal follow-up of individuals. We use assays for BED, avidity, viral load, and CD4 cell count data from clade B samples collected in several US epidemiologic cohorts between 1987 and 2010. Considering issues of accuracy, cost, and implementation, we identify optimal multiassay algorithms for estimating incidence. We find that the multiple-biomarker approach to cross-sectional HIV incidence estimation corrects the significant deficiencies of currently available approaches and is a potentially powerful and practical tool for HIV surveillance.
PMCID: PMC3626051  PMID: 23302151
acquired immunodeficiency syndrome; algorithms; cross-sectional studies; HIV; incidence; models, statistical
18.  Concomitant Socioeconomic, Behavioral, and Biological Factors Associated with the Disproportionate HIV Infection Burden among Black Men Who Have Sex with Men in 6 U.S. Cities 
PLoS ONE  2014;9(1):e87298.
American Black men who have sex with men (MSM) are disproportionately affected by HIV, but the factors associated with this concentrated epidemic are not fully understood.
Black MSM were enrolled in 6 US cities to evaluate a multi-component prevention intervention, with the current analysis focusing on the correlates of being newly diagnosed with HIV compared to being HIV-uninfected or previously diagnosed with HIV.
HPTN 061 enrolled 1553 Black MSM whose median age was 40; 30% self-identified exclusively as gay or homosexual, 29% exclusively as bisexual, and 3% as transgender. About 1/6th (16.2%) were previously diagnosed with HIV (PD); of 1263 participants without a prior HIV diagnosis 7.6% were newly diagnosed (ND). Compared to PD, ND Black MSM were younger (p<0.001); less likely to be living with a primary partner (p<0.001); more likely to be diagnosed with syphilis (p<0.001), rectal gonorrhea (p = 0.011) or chlamydia (p = 0.020). Compared to HIV-uninfected Black MSM, ND were more likely to report unprotected receptive anal intercourse (URAI) with a male partner in the last 6 months (p<0.001); and to be diagnosed with syphilis (p<0.001), rectal gonorrhea (p = 0.004), and urethral (p = 0.025) or rectal chlamydia (p<0.001). They were less likely to report female (p = 0.002) or transgender partners (p = 0.018). Multivariate logistic regression analyses found that ND Black MSM were significantly more likely than HIV-uninfected peers to be unemployed; have STIs, and engage in URAI. Almost half the men in each group were poor, had depressive symptoms, and expressed internalized homophobia.
ND HIV-infected Black MSM were more likely to be unemployed, have bacterial STIs and engage in URAI than other Black MSM. Culturally-tailored programs that address economic disenfranchisement, increase engagement in care, screen for STIs, in conjunction with safer sex prevention interventions, may help to decrease further transmission in this heavily affected community.
PMCID: PMC3909083  PMID: 24498067
19.  HIV Incidence Determination in the United States: A Multiassay Approach 
The Journal of Infectious Diseases  2012;207(2):232-239.
Background. Accurate testing algorithms are needed for estimating human immunodeficiency virus (HIV) incidence from cross-sectional surveys.
Methods. We developed a multiassay algorithm (MAA) for HIV incidence that includes the BED capture enzyme immunoassay (BED-CEIA), an antibody avidity assay, HIV load, and CD4+ T-cell count. We analyzed 1782 samples from 709 individuals in the United States who had a known duration of HIV infection (range, 0 to >8 years). Logistic regression with cubic splines was used to compare the performance of the MAA to the BED-CEIA and to determine the window period of the MAA. We compared the annual incidence estimated with the MAA to the annual incidence based on HIV seroconversion in a longitudinal cohort.
Results. The MAA had a window period of 141 days (95% confidence interval [CI], 94–150) and a very low false-recent misclassification rate (only 0.4% of 1474 samples from subjects infected for >1 year were misclassified as indicative of recent infection). In a cohort study, annual incidence based on HIV seroconversion was 1.04% (95% CI, .70%–1.55%). The incidence estimate obtained using the MAA was essentially identical: 0.97% (95% CI, .51%–1.71%).
Conclusions. The MAA is as sensitive for detecting recent HIV infection as the BED-CEIA and has a very low rate of false-recent misclassification. It provides a powerful tool for cross-sectional HIV incidence determination.
PMCID: PMC3532826  PMID: 23129760
HIV; incidence testing; United States; epidemiology
20.  Performance of a Limiting-Antigen Avidity Enzyme Immunoassay for Cross-Sectional Estimation of HIV Incidence in the United States 
PLoS ONE  2013;8(12):e82772.
A limiting antigen avidity enzyme immunoassay (HIV-1 LAg-Avidity assay) was recently developed for cross-sectional HIV incidence estimation. We evaluated the performance of the LAg-Avidity assay alone and in multi-assay algorithms (MAAs) that included other biomarkers.
Methods and Findings
Performance of testing algorithms was evaluated using 2,282 samples from individuals in the United States collected 1 month to >8 years after HIV seroconversion. The capacity of selected testing algorithms to accurately estimate incidence was evaluated in three longitudinal cohorts. When used in a single-assay format, the LAg-Avidity assay classified some individuals infected >5 years as assay positive and failed to provide reliable incidence estimates in cohorts that included individuals with long-term infections. We evaluated >500,000 testing algorithms, that included the LAg-Avidity assay alone and MAAs with other biomarkers (BED capture immunoassay [BED-CEIA], BioRad-Avidity assay, HIV viral load, CD4 cell count), varying the assays and assay cutoffs. We identified an optimized 2-assay MAA that included the LAg-Avidity and BioRad-Avidity assays, and an optimized 4-assay MAA that included those assays, as well as HIV viral load and CD4 cell count. The two optimized MAAs classified all 845 samples from individuals infected >5 years as MAA negative and estimated incidence within a year of sample collection. These two MAAs produced incidence estimates that were consistent with those from longitudinal follow-up of cohorts. A comparison of the laboratory assay costs of the MAAs was also performed, and we found that the costs associated with the optimal two assay MAA were substantially less than with the four assay MAA.
The LAg-Avidity assay did not perform well in a single-assay format, regardless of the assay cutoff. MAAs that include the LAg-Avidity and BioRad-Avidity assays, with or without viral load and CD4 cell count, provide accurate incidence estimates.
PMCID: PMC3873916  PMID: 24386116
21.  Correction: Association of pol Diversity with Antiretroviral Treatment Outcomes among HIV-Infected African Children 
PLoS ONE  2013;8(12):10.1371/annotation/dd945f7c-c50b-461d-ab38-15e8b0966458.
PMCID: PMC3873195
22.  Correction: Association of pol Diversity with Antiretroviral Treatment Outcomes among HIV-Infected African Children 
PLoS ONE  2013;8(12):10.1371/annotation/6937ccda-2f54-430d-94d0-b71d1ecc5273.
PMCID: PMC3861509
23.  Analysis of nevirapine resistance mutations in cloned HIV-1 variants from HIV-infected Ugandan infants using a single step amplification-sequencing method (AmpliSeq) 
AIDS research and human retroviruses  2008;24(9):1209-1213.
We analyzed genetic linkage of nevirapine (NVP) resistance mutations and the genetic complexity of HIV-1 variants in Ugandan infants who were HIV-infected despite single dose (SD) prophylaxis. Plasma samples were obtained from six HIV-infected infants who had two or more NVP resistance mutations detected by population sequencing (ViroSeq). ViroSeq PCR products were cloned and transformed, and a single step amplification-sequencing reaction (AmpliSeq) was used to analyze NVP resistance mutations in cloned HIV-1 variants directly from bacterial colonies. Fifty clones were analyzed for each infant sample. This analysis revealed numerous NVP resistance mutations not detected by population sequencing, genetically-linked NVP resistance mutations, and a high degree of genetic complexity at codons that influence NVP susceptibility.
PMCID: PMC2562759  PMID: 18788912
24.  Analysis of Nevirapine Resistance Mutations in Cloned HIV Type 1 Variants from HIV-Infected Ugandan Infants Using a Single-Step Amplification-Sequencing Method (AmpliSeq) 
AIDS Research and Human Retroviruses  2008;24(9):1209-1213.
We analyzed the genetic linkage of nevirapine (NVP) resistance mutations and the genetic complexity of HIV-1 variants in Ugandan infants who were HIV infected despite single dose (SD) prophylaxis. Plasma samples were obtained from six HIV-infected infants who had two or more NVP resistance mutations detected by population sequencing (ViroSeq). ViroSeq PCR products were cloned and transformed, and a single-step amplification-sequencing reaction (AmpliSeq) was used to analyze NVP resistance mutations in cloned HIV-1 variants directly from bacterial colonies. Fifty clones were analyzed for each infant sample. This analysis revealed numerous NVP resistance mutations not detected by population sequencing, genetically linked NVP resistance mutations, and a high degree of genetic complexity at codons that influence NVP susceptibility.
PMCID: PMC2562759  PMID: 18788912
25.  Antiretroviral Drug Susceptibility Among HIV-Infected Adults Failing Antiretroviral Therapy in Rakai, Uganda 
AIDS Research and Human Retroviruses  2012;28(12):1739-1744.
We analyzed antiretroviral drug susceptibility in HIV-infected adults failing first- and second-line antiretroviral treatment (ART) in Rakai, Uganda. Samples obtained from participants at baseline (pretreatment) and at the time of failure on first-line ART and second-line ART were analyzed using genotypic and phenotypic assays for antiretroviral drug resistance. Test results were obtained from 73 samples from 38 individuals (31 baseline samples, 36 first-line failure samples, and six second-line failure samples). Four (13%) of the 31 baseline samples had mutations associated with resistance to nucleoside or nonnucleoside reverse transcriptase inhibitors (NRTIs and NNRTIs, respectively). Among the 36 first-line failure samples, 31 (86%) had NNRTI resistance mutations and 29 (81%) had lamivudine resistance mutations; only eight (22%) had other NRTI resistance mutations. None of the six individuals failing a second-line protease inhibitor (PI)-based regimen had PI resistance mutations. Six (16%) of the participants had discordant genotypic and phenotypic test results. Genotypic resistance to drugs included in first-line ART regimens was detected prior to treatment and among participants failing first-line ART. PI resistance was not detected in individuals failing second-line ART. Surveillance for transmitted and acquired drug resistance remains a priority for scale-up of ART.
PMCID: PMC3505045  PMID: 22443282

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