Disclosure of positive HIV status in Sub-Saharan Africa has been associated with safer sexual practices and better antiretroviral therapy (ART) adherence, but associations with psychosocial function are unclear. We examined patterns and psychosocial correlates of disclosure in a Zimbabwean community. Two hundred HIV positive women at different stages of initiating ART participated in a cross-sectional study examining actual disclosures, disclosure beliefs, perceived stigma, self-esteem, depression, and quality of life. Ninety-seven percent of the women disclosed to at least one person, 78% disclosed to their current husband/partner, with an average disclosure of 4.0 persons per woman. The majority (85–98%) of disclosures occurred in a positive manner and 72–95% of the individuals reacted positively. Factors significantly correlated with HIV disclosure to partners included being married, later age at menses, longer duration of HIV since diagnosis, being on ART, being more symptomatic at baseline, ever having used condoms, and greater number of partners in the last year. In multivariate analysis, being married and age at menses predicted disclosure to partners. Positive disclosure beliefs, but not the total number of disclosures, significantly correlated with lower perceived stigma (rho=0.44 for personalized subscale and rho=0.51 for public subscale, both p<0.0001), higher self-esteem (rho=0.15, p=0.04), and fewer depressive symptoms (rho=−0.14, p=0.05). In conclusion, disclosure of positive HIV status among Zimbabwean women is common and is frequently met with positive reactions. Moreover, positive disclosure beliefs correlate significantly with psychosocial measures, including lower perceived stigma, higher self-esteem, and lower depression.

Aims

HIV-1 sequence diversity can affect host immune responses and phenotypic characteristics such as antiretroviral drug resistance. Current HIV-1 sequence diversity classification uses phylogeny-based methods to identify subtypes and recombinants, which may overlook distinct subpopulations within subtypes. While local epidemic studies have characterized sequence-level clustering within subtypes using phylogeny, identification of new genotype – phenotype associations are based on mutational correlations at individual sequence positions. We perform a systematic, global analysis of position-specific pol gene sequence variation across geographic regions within HIV-1 subtypes to characterize subpopulation differences that may be missed by standard subtyping methods and sequence-level phylogenetic clustering analyses.

Materials & methods

Analysis was performed on a large, globally diverse, cross-sectional pol sequence dataset. Sequences were partitioned into subtypes and geographic subpopulations within subtypes. For each subtype, we identified positions that varied according to geography using VESPA (viral epidemiology signature pattern analysis) to identify sequence signature differences and a likelihood ratio test adjusted for multiple comparisons to characterize differences in amino acid (AA) frequencies, including minority mutations. Synonymous nonsynonymous analysis program (SNAP) was used to explore the role of evolutionary selection witihin subtype C.

Results

In 7693 protease (PR) and reverse transcriptase (RT) sequences from untreated patients in multiple geographic regions, 11 PR and 11 RT positions exhibited sequence signature differences within subtypes. Thirty six PR and 80 RT positions exhibited within-subtype geography-dependent differences in AA distributions, including minority mutations, at both conserved and variable loci. Among subtype C samples from India and South Africa, nine PR and nine RT positions had significantly different AA distributions, including one PR and five RT positions that differed in consensus AA between regions. A selection analysis of subtype C using SNAP demonstrated that estimated rates of nonsynonymous and synonymous mutations are consistent with the possibility of positive selection across geographic subpopulations within subtypes.

Conclusion

We characterized systematic genotypic pol differences across geographic regions within subtypes that are not captured by the subtyping nomenclature. Awareness of such differences may improve the interpretation of future studies determining the phenotypic consequences of genetic backgrounds.

Summary

In HIV-1 subtype C infected populations in south India, we searched for novel mutations associated with failing antiretroviral therapy that included nucleoside reverse transcriptase (RT) inhibitors. HIV-1 RT sequences were generated from treated and untreated groups and each nucleotide position was analysed with appropriate corrections for multiple testing. We found that nonsynonymous mutations at positions 208 and 228 were strongly associated with the presence of thymidine analogue mutations in the treated group, and were not present at all in the naïve group. The role of these substitutions on treatment outcomes and the evolution of drug resistance in HIV-1 subtype-C infected populations warrant further investigation.

(See the editorial commentary by Hull and Montaner, on pages 1154–6.)

Background. AIDS Clinical Trials Group A5202 compared blinded abacavir/lamivudine (ABC/3TC) to tenofovir DF/emtricitabine (TDF/FTC) with efavirenz (EFV) or atazanavir/ritonavir (ATV/r) in human immunodeficiency virus (HIV)-infected treatment-naive patients, stratified by screening HIV RNA (< or ≥105 copies/mL). Due to higher virologic failure with ABC/3TC in the high HIV RNA stratum, blinded treatment was stopped in this group, but study follow-up continued for all patients.

Methods. Primary endpoints were times to virologic failure, regimen modification, and safety event.

Results. In the low HIV RNA stratum, time to virologic failure was similar for ABC/3TC vs TDF/FTC with ATV/r (hazard ratio [HR] 1.25, 95% confidence interval [CI] 0.76, 2.05) or EFV (HR 1.23, 95% CI 0.77, 1.96), with significantly shorter times to regimen modification for ABC/3TC with EFV or ATV/r and to safety events with EFV. Prior to stopping blinded treatment in the high stratum, higher virologic failure rates were seen with ABC/3TC with EFV (HR 2.46, 95% CI 1.20, 5.05) or ATV/r (HR 2.22, 95% CI 1.19, 4.14).

Conclusions. In the low HIV RNA stratum, times to virologic failure for ABC/3TC or TDF/FTC were not different with EFV or ATV/r. In the high stratum, virologic failure rate was significantly higher for ABC/3TC than for TDF/FTC when given with either EFV or ATV/r.

Introduction

Drug resistance mutations (DRM) in viral RNA are important in defining to provide effective antiretroviral therapy (ART) in HIV-1 infected patients. Detection of DRM in peripheral blood mononuclear cell (PBMC) DNA is another source of information, although the clinical significance of DRMs in proviral DNA is less clear.

Materials and Methods

From 25 patients receiving ART at a center in Zimbabwe, 32 blood samples were collected. Dideoxy-sequencing of gag-pol identified subtype and resistance mutations from plasma viral RNA and proviral DNA. Drug resistance was estimated using the calibrated population resistance tool on www.hivdb.stanford.edu database. Numerical resistance scores were calculated for all antiretroviral drugs and for the subjects’ reported regimen. Phylogenetic analysis as maximum likelihood was performed to determine the evolutionary distance between sequences.

Results

Of the 25 patients, 4 patients (2 of which had given 2 blood samples) were not known to be on ART (NA) and had exclusively wild-type virus, 17 had received Protease inhibitors (PI), 18, non-nucleoside reverse transcriptase inhibitors (NNRTI) and 19, two or more nucleoside reverse transcriptase inhibitors (NRTI). Of the 17 with history of PI, 10 had PI mutations, 5 had minor differences between mutations in RNA and DNA. Eighteen samples had NNRTI mutations, six of which demonstrated some discordance between DNA and RNA mutations. Although NRTI resistance mutations were frequently different between analyses, mutations resulted in very similar estimated phenotypes as measured by resistance scores. The numerical resistance scores from RNA and DNA for PIs differed between 2/10, for NNRTIs between 8/18, and for NRTIs between 17/32 pairs. When calculated resistance scores were collapsed, 3 pairs showed discordance between RNA and DNA for at least one PI, 6 were discordant for at least one NNRTI and 11 for at least one NRTI. Regarding phylogenetic evolutionary analysis, all RNA and DNA sequence pairs clustered closely in a maximum likelihood tree.

Conclusion

PBMC DNA could be useful for testing drug resistance in conjunction with plasma RNA where the results of each yielded complementary information about drug resistance. Identification of DRM, archived in proviral DNA, could be used to provide for sustainable public health surveillance among subtype C infected patients.

Objective

To evaluate virologic response rates of lopinavir/ritonavir (LPV/r) monotherapy as second-line antiretroviral treatment (ART) among adults in resource-limited settings (RLS).

Design

Open-label pilot study of LPV/r monotherapy in participants on first-line non-nucleoside reverse transcriptase inhibitor 3-drug combination ART with plasma HIV-1 RNA 1000–200 000 copies/mL.

Methods

Participants were recruited from 5 sites in Africa and Asia within the AIDS Clinical Trials Group (ACTG) network. All participants received LPV/r 400/100mg twice daily. The primary endpoint was remaining on LPV/r monotherapy without virologic failure (VF) at week 24. Participants with virologic failure were offered addition of emtricitabine and tenofovir (FTC/TDF) to LPV/r.

Results

Mutations associated with drug resistance were encountered in nearly all individuals screened for the study. One hundred and twenty-three participants were enrolled, and 122 completed 24 weeks on study. A high proportion remained on LPV/r monotherapy without VF at 24 weeks (87%). Archived samples with HIV-1 RNA levels < 400 at week 24 (n = 102) underwent ultrasensitive assay. Of these subjects, 62 had levels < 40 copies/mL and 30 had levels 40–200. Fifteen subjects experienced VF, among whom 11 had resistance assessed, and 2 had emergent protease inhibitor mutations. The presence of baseline thymidine analogue mutations and K65R predicted a lower VF rate. Thirteen subjects with VF added FTC/TDF, and 1 subject added FTC/ TDF without VF. At study week 48, 11/14 adding FTC/TDF had HIV-1 RNA levels < 400 copies/mL.

Conclusions

In this pilot study conducted in diverse RLS, LPV/r monotherapy as second-line ART demonstrated promising activity.

Background

Limited data compare once-daily options for initial therapy for HIV-1.

Objective

To compare time to virologic failure; first grade-3 or -4 sign, symptom, or laboratory abnormality (safety); and change or discontinuation of regimen (tolerability) for atazanavir plus ritonavir with efavirenz-containing initial therapy for HIV-1.

Design

A randomized equivalence trial accrued from September 2005 to November 2007, with median follow-up of 138 weeks. Regimens were assigned by using a central computer, stratified by screening HIV-1 RNA level less than 100 000 copies/mL or 100 000 copies/mL or greater; blinding was known only to the site pharmacist. (ClinicalTrials.gov registration number: NCT00118898)

Setting

59 AIDS Clinical Trials Group sites in the United States and Puerto Rico.

Patients

Antiretroviral-naive patients.

Intervention

Open-label atazanavir plus ritonavir or efavirenz, each given with with placebo-controlled abacavir–lamivudine or tenofovir disoproxil fumarate (DF)–emtricitabine.

Measurements

Primary outcomes were time to virologic failure, safety, and tolerability events. Secondary end points included proportion of patients with HIV-1 RNA level less than 50 copies/mL, emergence of drug resistance, changes in CD4 cell counts, calculated creatinine clearance, and lipid levels.

Results

463 eligible patients were randomly assigned to receive atazanavir plus ritonavir and 465 were assigned to receive efavirenz, both with abacavir–lamivudine; 322 (70%) and 324 (70%), respectively, completed follow-up. The respective numbers of participants in each group who received tenofovir DF–emtricitabine were 465 and 464; 342 (74%) and 343 (74%) completed follow-up. Primary efficacy was similar in the group that received atazanavir plus ritonavir and and the group that received efavirenz and did not differ according to whether abacavir–lamivudine or tenofovir DF–emtricitabine was also given. Hazard ratios for time to virologic failure were 1.13 (95% CI, 0.82 to 1.56) and 1.01 (CI, 0.70 to 1.46), respectively, although CIs did not meet prespecified criteria for equivalence. The time to safety (P = 0.048) and tolerability (P < 0.001) events was longer in persons given atazanavir plus ritonavir than in those given efavirenz with abacavir–lamivudine but not with tenofovir DF–emtricitabine.

Limitations

Neither HLA-B*5701 nor resistance testing was the standard of care when A5202 enrolled patients. The third drugs, atazanavir plus ritonavir and efavirenz, were open-label; the nucleoside reverse transcriptase inhibitors were prematurely unblinded in the high viral load stratum; and 32% of patients modified or discontinued treatment with their third drug.

Conclusion

Atazanavir plus ritonavir and efavirenz have similar antiviral activity when used with abacavir–lamivudine or tenofovir DF–emtricitabine.

Primary Funding Source

National Institutes of Health.

During the course of HIV infection, some HIV-1 viruses switch from using the CCR5 (R5) coreceptor to using CXCR4 (X4). Here, we describe two subtype C isolates from a Zimbabwean patient that switched from using R5 to using both R5 and X4 with an accompanying addition of five amino acids to the V3 loop region of envelope. The insert appears to be derived from the human genome rather than a duplication within HIV-1.

We conducted a nested case-control study of placental malaria (PM) and mother-to-child transmission (MTCT) of human immunodeficiency virus-1 (HIV-1) within a prospective cohort of 627 mother-infant pairs followed from October 1989 until April 1994 in rural Rwanda. Sixty stored placentas were examined for PM and other placental pathology, comparing 20 HIV-infected mother-infant (perinatal transmitter) pairs, 20 HIV-uninfected pairs, and 20 HIV-infected mothers who did not transmit to their infant perinatally. Of 60 placentas examined, 45% showed evidence of PM. Placental malaria was associated with increased risk of MTCT of HIV-1 (adjusted odds ratio [aOR] = 6.3; 95% confidence interval [CI] = 1.4–29.1), especially among primigravidae (aOR = 12.0; 95% CI = 1.0–150; P < 0.05). Before antiretroviral therapy or prophylaxis, PM was associated with early infant HIV infection among rural Rwandan women living in a hyper-endemic malaria region. Primigravidae, among whom malaria tends to be most severe, may be at higher risk.

We created a panel of 10 representative multi-nonnucleoside reverse transcriptase inhibitor (NNRTI)-resistant recombinant infectious molecular HIV-1 clones to assist researchers studying NNRTI resistance or developing novel NNRTIs. The cloned viruses contain most of the major NNRTI resistance mutations and most of the significantly associated mutation pairs that we identified in two network analyses. Each virus in the panel has intermediate- or high-level resistance to all or three of the four most commonly used NNRTIs.

Background

Asymptomatic Chlamydia trachomatis (chlamydia) and Neisseria gonorrhoeae (gonorrhea) infections pose diagnostic and control problems in developing countries.

Methods

Participants in China, India, Peru, Russia, and Zimbabwe were screened for C. trachomatis and N. gonorrhoeae infections and symptoms.

Results

A total of 18,014 participants were evaluated at baseline, 15,054 at 12 months, and 14,243 at 24 months. The incidence of chlamydia in men was 2.0 per 100 person years both from baseline to 12 months and from 12 to 24 months, and in women, 4.6 from baseline to 12 months and 3.6 from 12 to 24 months; a range of 31.2% to 100% reported no symptoms across the 5 countries. The incidence of gonorrhea in men was 0.3 per 100 person years both from baseline to 12 months and from 12 to 24 months, and in women, 1.4 from baseline to 12 months and 1.1 from 12 to 24 months; a range of 66.7% to 100% reported no symptoms. Being female, aged 18 to 24 years, and having more than 1 partner were associated with both the infections. In addition, being divorced, separated, or widowed was associated with gonorrhea. Being male, having 6+ years of education, and reporting only 1 partner were associated with having no symptoms among those infected with chlamydia. No variables correlated with asymptomatic gonorrhea among those infected.

Conclusion

A high prevalence and incidence of asymptomatic sexually transmitted infections was identified among men and women in a wide variety of settings. More effective programs are needed to identify and treat chlamydia and gonorrhea infections, especially among women, young adults, those with multiple partners, those repeatedly infected, and particularly those at risk without symptoms. The risk of transmission from persons with no symptoms requires further study.

Abstract

HIV-1 transmitted drug resistance (TDR) could reverse the gains of antiretroviral rollout. To ensure that current first-line therapies remain effective, TDR levels in recently infected treatment-naive patients need to be monitored. A literature review and data mining exercise was carried out to determine the temporal trends in TDR in South Africa. In addition, 72 sequences from seroconvertors identified from Africa Centre's 2010 HIV surveillance round were also examined for TDR. Publicly available data on TDR were retrieved from GenBank, curated in RegaDB, and analyzed using the Calibrated Population Resistance Program. There was no evidence of TDR from the 2010 rural KwaZulu Natal samples. Ten datasets with a total of 1618 sequences collected between 2000 and 2010 were pooled to provide a temporal analysis of TDR. The year with the highest TDR rate was 2002 [6.67%, 95% confidence interval (CI): 3.09–13.79%; n=6/90]. After 2002, TDR levels returned to <5% (WHO low-level threshold) and showed no statistically significant increase in the interval between 2002 and 2010. The most common mutations were associated with NNRTI resistance, K103N, followed by Y181C and Y188C/L. Five sequences had multiple resistance mutations associated with NNRTI resistance. There is no evidence of TDR in rural KwaZulu-Natal. TDR levels in South Africa have remained low following a downward trend since 2003. Continuous vigilance in monitoring of TDR is needed as more patients are initiated and maintained onto antiretroviral therapy.

Background

We hypothesized that drug resistance mutations would impact clinical outcomes associated with HIV-1 infection.

Methods

A matched case-control study of participants in AIDS Clinical Trials Group Longitudinal Linked Randomized Trials (ALLRT). Cases experienced an AIDS-defining event (ADE) or mortality, and controls did not. One hundred thirty four cases were identified and matched to a total of 266 controls by age, sex, treatment regimen, and length of follow-up. Both cases and controls had HIV RNA levels of ≥ 500 copies/mL within 24 weeks of an event. Population-based genotyping at or near the time of the event was used to evaluate the impact of resistance mutations on incidence of ADE and/or death using conditional logistic regression models.

Results

One hundred and four cases and 183 controls were analyzed. Median time to event was 99 weeks; six cases were deaths. At baseline, cases had lower CD4 (median 117 vs. 235 cells/mm3, p<0.0001) and higher HIV RNA levels (median 205,000 vs. 57,000 copies/mL, p=0.03). No significant differences in resistance were seen between cases and controls.

Conclusions

In this rigorously designed case-control study, lower CD4 cell counts and higher virus loads, not antiretroviral drug resistance, were strongly associated ADE and mortality.

Background

We previously demonstrated in vitro that zidovudine (AZT) selects for A371V in the connection domain and Q509L in ribonuclease H (RNase H) domain of HIV-1 reverse transcriptase (RT) which, together with the thymidine analog mutations D67N, K70R and T215F, confer greater than 100-fold AZT resistance. The goal of the current study was to determine whether AZT monotherapy in HIV-1 infected patients also selects the A371V, Q509L or other mutations in the C-terminal domains of HIV-1 RT.

Methodology/Principal Findings

Full-length RT sequences in plasma obtained pre- and post-therapy were compared in 23 participants who received AZT monotherapy from the AIDS Clinical Trials Group study 175. Five of the 23 participants reached a primary study endpoint. Mutations significantly associated with AZT monotherapy included K70R (p = 0.003) and T215Y (p = 0.013) in the polymerase domain of HIV-1 RT, and A360V (p = 0.041) in the connection domain of HIV-1 RT. HIV-1 drug susceptibility assays demonstrated that A360V, either alone or in combination with thymidine analog mutations, decreased AZT susceptibility in recombinant viruses containing participant-derived full-length RT sequences or site-directed mutant RT. Biochemical studies revealed that A360V enhances the AZT-monophosphate excision activity of purified RT by significantly decreasing the frequency of secondary RNase H cleavage events that reduce the RNA/DNA duplex length and promote template/primer dissociation.

Conclusions

The A360V mutation in the connection domain of RT was selected in HIV-infected individuals that received AZT monotherapy and contributed to AZT resistance.

Synopsis

Great progress has been made in understanding the pathogenesis, treatment, and transmission of HIV and the factors influencing the risk of mother-to-child transmission (MTCT). However, many questions regarding the molecular evolution and genetic diversity of HIV in the context of MTCT remain unanswered. Further research to identify the selective factors governing which variants are transmitted, how the compartmentalization of HIV in different cells and tissues contributes to transmission, and the influence of host immunity, viral diversity and recombination on MTCT may provide insight into new prevention strategies and the development of an effective HIV vaccine.

Background

Emergence of HIV-1 drug resistance is at times an inevitable and anticipated consequence of antiretroviral therapy (ART) failure. We examined drug resistance patterns and virus re-suppression among subtype C-infected South African patients receiving first-line ART.

Methods

Treatment records of 431 patients on NNRTI-containing regimens for a median of 45 months were analyzed. Patients with viral load (VL) >400 copies/mL were followed and drug resistance mutations (DRM) were re-assessed. Associations between clinical/demographic measures and drug resistance/virologic outcomes were examined using Fisher exact and ordinal and logistic regression.

Results

Ten percent of patients (43/431) were viremic at enrollment (98% previously suppressed); sequences were obtained from 38/43. Of those, 82% had 1–7 DRM. In bivariate analysis remote exposure to single-dose nevirapine or prior ART; higher CD4 counts; lower VL; and >6 months of virologic failure were significantly associated with number of DRM. Of 25 viremic patients followed for a median of 8 months on a continued first-line regimen, 12 (48%) re-suppressed, six with K103N and three with M184V. Thirteen (52%) had continued virologic failure which was significantly associated with detectable VL>6 months prior to enrollment and number of DRM.

Conclusion

Among these HIV-1 subtype C-infected patients, DRM numbers and patterns were associated with prior exposure to sub-optimal ART, adherence and duration of virologic failure. Viral re-suppression in the presence of K103N and M184V challenges assumptions about drug resistance. In resource-limited settings, where genotyping and alternative drug options are unavailable, continuing first-line treatment, reinforcing adherence and regular virologic monitoring may be effective even after virologic failure.

Background:

We assessed risk factors for viremia and drug resistance (DR) among long-term recipients of antiretroviral therapy (ART) in South Africa.

Methods:

In 2008, we conducted a cross-sectional study among patients receiving ART for ≥12 months. Genotypic resistance testing was performed on individuals with a viral load >400 RNA copies/ml. Multiple logistic regression analysis was used to assess associations.

Results:

Of 998 subjects, 75% were women with a median age of 41. Most (64%) had been on treatment for >3 years. The prevalence of viremia was 14% (n=139); 12% (102/883) on first-line (i.e. NNRTI based regimen) and 33% (37/115) on second-line (i.e. PI based regimen) ART. Of viremic patients, 78% had DR mutations. For NRTIs, NNRTIs and PIs the prevalence of mutations was 64%, 81% and 2% among first-line and 29%, 54% and 6% among second-line failures respectively. M184V/I, K103N and V106A/M were the most common mutations.

Significant risk factors associated with viremia on first-line included concurrent tuberculosis treatment (OR 6.4, 2.2-18.8, p<0.01) and a recent history of poor adherence (OR 2.7, 1.3-5.6, p=0.01). Among second-line failures, attending a public clinic (OR 4.6, 1.8-11.3, p<0.01) and not having a refrigerator at home (OR 6.7, 1.2-37.5, p=0.03) were risk factors for virological failure.

Conclusions:

Risk factors for viral failure were line-regimen dependent. Second-line ART recipients had a higher rate of viremia, albeit with infrequent PI DR mutations. Measures to maintain effective virologic suppression should include increased adherence counseling, attention to concomitant tuberculosis treatment and heat-stable formulations of second-line ART regimens.

The rapid scale-up of highly active antiretroviral therapy (HAART) and use of single dose Nevirapine (SD NVP) for prevention of mother-to-child transmission (pMTCT) have raised fears about the emergence of resistance to the first line antiretroviral drug regimens. A cross-sectional study was conducted to determine the prevalence of primary drug resistance (PDR) in a cohort of young (<25 yrs) HAART-naïve HIV pregnant women attending antenatal clinics in Chitungwiza, Zimbabwe. Whole blood was collected in EDTA for CD4 counts, viral load, serological estimation of duration of infection using the BED Calypte assay and genotyping for drug resistance. Four hundred and seventy-one women, mean age 21 years; SD: 2.1 were enrolled into the study between 2006 and 2007. Their median CD4 count was 371cells/µL; IQR: 255–511 cells/µL. Two hundred and thirty-six samples were genotyped for drug resistance. Based on the BED assay, 27% were recently infected (RI) whilst 73% had long-term infection (LTI). Median CD4 count was higher (p<0.05) in RI than in women with LTI. Only 2 women had drug resistance mutations; protease I85V and reverse transcriptase Y181C. Prevalence of PDR in Chitungwiza, 4 years after commencement of the national ART program remained below WHO threshold limit (5%). Frequency of recent infection BED testing is consistent with high HIV acquisition during pregnancy. With the scale-up of long-term ART programs, maintenance of proper prescribing practices, continuous monitoring of patients and reinforcement of adherence may prevent the acquisition and transmission of PDR.

The concentration of human immunodeficiency virus type 1 (HIV-1) is generally lower in breast milk than in blood. Mastitis, or inflammation of the breast, is associated with increased levels of milk HIV-1 and risk of mother-to-child transmission through breastfeeding. We hypothesized that mastitis facilitates the passage of HIV-1 from blood into milk or stimulates virus production within the breast. HIV-1 env sequences were generated from single amplicons obtained from breast milk and blood samples in a cross-sectional study. Viral compartmentalization was evaluated using several statistical methods, including the Slatkin and Maddison (SM) test. Mastitis was defined as an elevated milk sodium (Na+) concentration. The association between milk Na+ and the pairwise genetic distance between milk and blood viral sequences was modeled using linear regression. HIV-1 was compartmentalized within milk by SM testing in 6/17 (35%) specimens obtained from 9 women, but all phylogenetic clades included viral sequences from milk and blood samples. Monotypic sequences were more prevalent in milk samples than in blood samples (22% versus 13%; P = 0.012), which accounted for half of the compartmentalization observed. Mastitis was not associated with compartmentalization by SM testing (P = 0.621), but Na+ was correlated with greater genetic distance between milk and blood HIV-1 populations (P = 0.041). In conclusion, local production of HIV-1 within the breast is suggested by compartmentalization of virus and a higher prevalence of monotypic viruses in milk specimens. However, phylogenetic trees demonstrate extensive mixing of viruses between milk and blood specimens. HIV-1 replication in breast milk appears to increase with inflammation, contributing to higher milk viral loads during mastitis.

Background

Affordable strategies to prevent treatment failure on first-line regimens among HIV patients are essential for the long-term success of antiretroviral therapy (ART) in sub-Saharan Africa. WHO recommends using routinely collected data such as adherence to drug-refill visits as early warning indicators. We examined the association between adherence to drug-refill visits and long-term virologic and immunologic failure among non-nucleoside reverse transcriptase inhibitor (NNRTI) recipients in South Africa.

Methods

In 2008, 456 patients on NNRTI-based ART for a median of 44 months (range 12–99 months; 1,510 person-years) were enrolled in a retrospective cohort study in Soweto. Charts were reviewed for clinical characteristics before and during ART. Multivariable logistic regression and Kaplan-Meier survival analysis assessed associations with virologic (two repeated VL>50 copies/ml) and immunologic failure (as defined by WHO).

Results

After a median of 15 months on ART, 19% (n = 88) and 19% (n = 87) had failed virologically and immunologically respectively. A cumulative adherence of <95% to drug-refill visits was significantly associated with both virologic and immunologic failure (p<0.01). In the final multivariable model, risk factors for virologic failure were incomplete adherence (OR 2.8, 95%CI 1.2–6.7), and previous exposure to single-dose nevirapine or any other antiretrovirals (adj. OR 2.1, 95%CI 1.2–3.9), adjusted for age and sex. In Kaplan-Meier analysis, the virologic failure rate by month 48 was 19% vs. 37% among adherent and non-adherent patients respectively (logrank p value = 0.02).

Conclusion

One in five failed virologically after a median of 15 months on ART. Adherence to drug-refill visits works as an early warning indicator for both virologic and immunologic failure.

Background

Adherence is a necessary part of successful antiretroviral treatment (ART). We assessed risk factors for incomplete adherence among a cohort of HIV-infected women initiating ART and examined associations between adherence and virologic response to ART.

Methods

A secondary data analysis was conducted on a cohort of 154 women initiating non-nucleoside reverse transcriptase inhibitor (NNRTI)-based ART at a single site in Johannesburg, South Africa. Ninety women had been enrolled in a prevention of mother-to-child transmission (pMTCT) program and were exposed to single-dose nevirapine (sdNVP) >18 months earlier. Women were interviewed pre-treatment and clinical, virologic and adherence data were collected during follow-up to 24 weeks. Incomplete adherence to ART was defined as returning >5% of medications, estimated by pill counts at scheduled visits. Multivariable logistic regression analysis and unadjusted odds ratio (95%CI) were performed, using STATA/SE (ver 10.1).

Results

About half of the women (53%) were <30 years of age, 63% had <11 years of schooling, 69% were unemployed and 37% lived in a shack. Seven percent of women had a viral load >400 copies/ml at 24 weeks and 37% had incomplete adherence at one or more visits. Incomplete adherence was associated with less education (p = 0.01) and lack of financial support from a partner (p = 0.02) after adjustment for confounders. Only when adherence levels dropped below 80% was there a significant association with viremia in the group overall (p = 0.02) although adherence <95% was associated with viremia in the sdNVP-exposed group (p = 0.03). The main reasons for incomplete adherence were being away from home, busy with other things and forgetting to take their medication.

Conclusion

Virologic response to NNRTI-treatment in the cohort was excellent. However, women who received sdNVP were at greater risk of virologic failure when adherence was <95%. Women exposed to sdNVP, and those with less education and less social support may benefit from additional adherence counseling to ensure the long-term success of ART. More than 80% adherence may be sufficient to maintain virologic suppression on NNRTI-based regimens in the short-term, however complete adherence should be encouraged.

Background

Current World Health Organization (WHO) guidelines for treatment of HIV in resource-limited settings call for two antiretroviral regimens. The effectiveness and cost-effectiveness of increasing the number of antiretroviral regimens is unknown.

Methods

Using a simulation model, we compared the survival and costs of current WHO regimens with two 3-regimen strategies: an initial regimen of three nucleoside reverse transcriptase inhibitors followed by the WHO regimens; and the WHO regimens followed by a regimen with a second-generation boosted protease inhibitor (2bPI). We evaluated monitoring with CD4 counts only and with both CD4 counts and viral load. We used cost and effectiveness data from Cape Town, and tested all assumptions in sensitivity analyses.

Results

Over the lifetime of the cohort, 25.6% of individuals failed both WHO regimens by virologic criteria. However, when patients were monitored using CD4 counts alone, only 6.5% were prescribed additional HAART, due to missed and delayed detection of failure. The life expectancy gain for individuals who took a 2bPI was 6.7–8.9 months, depending on the monitoring strategy. When CD4 alone was available, adding a regimen with a 2bPI was associated with an incremental cost-effectiveness ratio of $2,581 per year-of-life gained, and when viral load was available, the ratio was $6,519 per year-of-life gained. Strategies with triple-NRTI regimens in initial therapy were dominated. Results were sensitive to the price of 2bPIs.

Conclusions

About 1 in 4 individuals who start HAART in sub-Saharan Africa will fail currently recommended regimens. At current prices, adding a regimen with a 2bPI is cost-effective for South Africa and other middle-income countries by WHO standards.

This study compared the role of genotypic susceptibility scores (GSS) as a predictor of virologic response in a group (n = 234) of HIV-infected, protease inhibitor (PI)-experienced subjects. Two scoring methods [discrete genotypic susceptibility score (dGSS) and continuous genotypic susceptibility score (cGSS)] were developed. Each drug in the subject's regimen was given a binary susceptibility score using Stanford inferred drug resistance scores to calculate the dGSS. In contrast to the dGSS, the cGSS model was designed to reflect partial susceptibility to a drug. Both GSS were independent predictors of week 16 virologic response. We also compared the GSS to a phenotypic susceptibility score (PSS) model on a subset of subjects that had both GSS and PSS performed, and found that both models were predictive of virologic response. Genotypic analyses at enrollment showed that subjects who were virologic nonresponders at week 16 revealed enrichment of several mutated codons associated with nucleoside reverse transcriptase inhibitors (NRTI) (codons 67, 69, 70, 118, 215, and 219) or PI resistance (codons 10, 24, 71, 73, and 88) compared to subjects who were virologic responders. Regression analyses revealed that protease mutations at codons 24 and 90 were most predictive of poor virologic response, whereas mutations at 82 were associated with enhanced virologic response. Certain NNRTI-associated mutations, such as K103N, were rapidly selected in the absence of NRTIs. These data indicate that GSS may be a useful tool in selecting drug regimens in HIV-1-infected subjects to maximize virologic response and improve treatment outcomes.

Objective

To investigate the origins and evolutionary history of subtype C HIV-1 in Zimbabwe in a context of regional conflict and migration.

Design

HIV-1C pol sequence datasets were generated from four sequential cohorts of antenatal women in Harare, Zimbabwe sampled over 15 years (1991–2006).

Methods

One hundred and seventy-seven HIV-1C pol sequences were obtained from four successive cohorts in Zimbabwe. Maximum-likelihood methods were used to explore phylogenetic relationships between Zimbabwean HIV-1C sequences and subtype C strains from other regions. A Bayesian coalescent-based framework was used to estimate evolutionary parameters for HIV-1C in Zimbabwe, including origin and demographic growth patterns.

Results

Zimbabwe HIV-1C pol demonstrated increasing sequence divergence over the 15-year period. Nearly all Zimbabwe sequences clustered phylogenetically with subtype C strains from neighboring countries. Bayesian evolutionary analysis indicated a most recent common ancestor date of 1973 with three epidemic growth phases: an initial slow phase (1970s) followed by exponential growth (1980s), and a linearly expanding epidemic to the present. Bayesian trees provided evidence for multiple HIV-1C introductions into Zimbabwe during 1979–1981, corresponding with Zimbabwean national independence following a period of socio-political instability.

Conclusion

The Zimbabwean HIV-1C epidemic likely originated from multiple introductions in the late 1970s and grew exponentially during the 1980s, corresponding to changing political boundaries and rapid population influx from neighboring countries. The timing and phylogenetic clustering of the Zimbabwean sequences is consistent with an origin in southern Africa and subsequent expansion. HIV-1 sequence data contain important epidemiological information, which can help focus treatment and prevention strategies in light of more recent political volatility in Zimbabwe.

Commercial HIV-1 genotypic resistance assays are very expensive, particularly for use in resource-constrained settings like India. Hence a cost effective in-house assay for drug resistance was validated against the standard ViroSeq™ HIV-1 Genotyping System 2.0 (Celera Diagnostics, CA, USA). A total of 50 samples were used for this evaluation (21 proficiency panels and 29 clinical isolates). Known resistance positions within HIV-1 protease (PR) region (1–99 codons) and HIV-1 reverse-transcriptase (RT) region (1–240 codons) were included. The results were analysed for each codon as follows: (i) concordant; (ii) partially concordant; (iii) indeterminate and (iv) discordant. A total of 2750 codons (55 codons per patient sample × 50 samples) associated with drug resistance (1050 PR and 1700 RT) were analysed. For PR, 99% of the codon results were concordant and 1% were partially concordant. For RT, 99% of the codon results were concordant, 0.9% were partially concordant and 0.1% were discordant. No indeterminate results were observed and the results were reproducible. Overall, the in-house assay provided comparable results to those of US FDA approved ViroSeq™, which costs about a half of the commercial assay ($ 100 vs. $ 230), making it suitable for resource-limited settings.