Population pharmacokinetics of rifabutin among HIV/TB co-infected children on lopinavir/ritonavir-based antiretroviral therapy.

In adults requiring protease inhibitor (PI)-based antiretroviral therapy (ART), replacing rifampicin with rifabutin is a preferred option, but there is lack of evidence to guide rifabutin dosing in children, especially with PIs. We aimed to characterize the population pharmacokinetics of rifabutin and 25-O-desacetyl rifabutin (des-rifabutin) in children and optimize its dose. We included children from three age cohorts: (i) <1-year-old cohort and (ii) 1- to 3-year-old cohort, who were ART naïve and received 15- to 20-mg/kg/day rifabutin for 2 weeks followed by lopinavir/ritonavir (LPV/r)-based ART with 5.0- or 2.5 mg/kg/day rifabutin, respectively, while the (iii) >3-year-old cohort was ART-experienced and received 2.5-mg/kg/day rifabutin with LPV/r-based ART. Non-linear mixed-effects modeling was used to interpret the data. Monte Carlo simulations were performed to evaluate the study doses and optimize dosing using harmonized weight bands. Twenty-eight children were included, with a median age of 10 (range 0.67-15.0) years, a median weight of 11 (range 4.5-45) kg, and a median weight-for-age z score of -3.33 (range -5.15 to -1.32). A two-compartment disposition model, scaled allometrically by weight, was developed for rifabutin and des-rifabutin. LPV/r increased rifabutin bioavailability by 158% (95% confidence interval: 93.2%-246.0%) and reduced des-rifabutin clearance by 76.6% (74.4%-78.3%). Severely underweight children showed 26% (17.9%-33.7%) lower bioavailability. Compared to adult exposures, simulations resulted in higher median steady-state rifabutin and des-rifabutin exposures in 6-20 kg during tuberculosis-only treatment with 20 mg/kg/day. During LPV/r co-treatment, the 2.5-mg/kg/day dose achieved similar exposures to adults, while the 5-mg/kg/day dose resulted in higher exposures in children >7 kg. All study doses maintained a median Cmax of <900 µg/L. The suggested weight-band dosing matches adult exposures consistently across weights and simplifies dosing.

Timeliness of Point-of-Care Viral Load Results Improves Human Immunodeficiency Virus Monitoring in Nigeria.

BACKGROUND: Human immunodeficiency virus (HIV) viral load (VL) monitoring is critical for antiretroviral therapy (ART) management. Point-of-care (POC) VL testing has been reported to be feasible and preferred over standard-of-care (SOC) testing in many low- and middle-income country settings where rapid results could improve patient outcomes. METHODS: The timeliness of receipt of VL results was evaluated in an open-label, randomized, controlled trial among patients newly initiating ART. Clinical outcomes with POC VL monitoring using Cepheid Xpert vs SOC VL at Jos University Teaching Hospital and Comprehensive Health Centre Zamko in Nigeria were assessed. We determined time between specimen collection and recording of VL in patient charts, receipt of results, and ART switch for those who met virologic failure criteria. RESULTS: Between April 2018 and October 2019, we screened 696 ART-naive individuals; 273 were randomized to POC and 268 to SOC HIV-1 VL testing. Participants in the POC arm received VL results significantly faster than those in the SOC arm (0.1 median days, interquartile range [IQR], 0.1-0.2 vs 143.1 days, IQR, 56.0-177.1, respectively; P < .0001). Participants in the POC arm with confirmed virologic failure vs those in the SOC arm were switched more rapidly to a second-line regimen (0 median days, IQR, 0-28 vs 66 days, IQR, 63-123, respectively; P = .03). CONCLUSIONS: POC VL testing resulted in significant improvement in the timeliness of VL result receipt by patients and use for effective HIV clinical management. In patients experiencing VL failure, POC monitoring enabled prompt switching to second-line ART regimens. CLINICAL TRIALS REGISTRATION: NCT03533868.

Rifabutin pharmacokinetics and safety among TB/HIV-coinfected children receiving lopinavir/ritonavir-containing second-line ART.

BACKGROUND: Treatment options are limited for TB/HIV-coinfected children who require PI-based ART. Rifabutin is the preferred rifamycin for adults on PIs, but the one study evaluating rifabutin with PIs among children was stopped early due to severe neutropenia. METHODS: We evaluated rifabutin safety and plasma pharmacokinetics among coinfected children 3-15 years of age receiving rifabutin 2.5 mg/kg daily with standard doses of lopinavir/ritonavir. The AUC0-24 at 2, 4 and 8 weeks after rifabutin initiation was described using intensive sampling and non-compartmental analysis. Clinical and laboratory toxicities were intensively monitored at 12 visits throughout the study. RESULTS: Among 15 children with median (IQR) age 13.1 (10.9-14.0) years and weight 25.5 (22.3-30.5) kg, the median (IQR) rifabutin AUC0-24 was 5.21 (4.38-6.60) µg·h/mL. Four participants had AUC0-24 below 3.8 µg·h/mL (a target for the population average exposure) at week 2 and all had AUC0-24 higher than 3.8 µg·h/mL at the 4 and 8 week visits. Of 506 laboratory evaluations during rifabutin, grade 3 and grade 4 abnormalities occurred in 16 (3%) and 2 (0.4%) instances, respectively, involving 9 (60%) children. Specifically, grade 3 (n = 4) and grade 4 (n = 1) neutropenia resolved without treatment interruption or clinical sequelae in all patients. One child died at week 4 of HIV-related complications. CONCLUSIONS: In children, rifabutin 2.5 mg/kg daily achieved AUC0-24 comparable to adults and favourable HIV and TB treatment outcomes were observed. Severe neutropenia was relatively uncommon and improved with ongoing rifabutin therapy. These data support the use of rifabutin for TB/HIV-coinfected children who require lopinavir/ritonavir.

Pharmacokinetics of adjusted-dose 8-hourly lopinavir/ritonavir in HIV-infected children co-treated with rifampicin.

OBJECTIVES: To evaluate the proportion of children with lopinavir Cmin ≥1 mg/L when receiving a novel 8-hourly lopinavir/ritonavir dosing strategy during rifampicin co-treatment. METHODS: HIV-infected children on lopinavir/ritonavir and rifampicin were enrolled in a prospective pharmacokinetic study. Children were switched from standard-of-care lopinavir/ritonavir-4:1 with additional ritonavir (1:1 ratio) twice daily to 8-hourly lopinavir/ritonavir-4:1 using weight-banded dosing. Rifampicin was dosed at 10-20 mg/kg/day. After 2 weeks, plasma samples were collected ∼2, 4, 6, 8 and 10 h after the morning lopinavir/ritonavir-4:1 dose, ALT was obtained to assess safety and treatment was switched back to standard of care. ClinicalTrials.gov registration number: NCT01637558. RESULTS: We recruited 11 children in two weight bands: 5 (45%) were 10-13.9 kg and received 20-24 mg/kg/dose of lopinavir and 6 (55%) children weighed 6-9.9 kg and received 20-23 mg/kg/dose of lopinavir. The median age was 15 months (IQR = 12.6-28.8 months). The median (IQR) lopinavir Cmin was 3.0 (0.1-5.5) mg/L. Seven (63.6%) of the 11 children had Cmin values ≥1 mg/L. Children with a lopinavir mg/kg dose below the median 21.5 were more likely to have Cmin <1 mg/L (P = 0.02). There was a strong positive correlation between lopinavir and ritonavir concentrations. No associations were found between lopinavir AUC2-10 and age, sex, weight, nutritional status or mg/kg/dose of lopinavir. CONCLUSIONS: These data do not support the use of 8-hourly lopinavir/ritonavir at studied doses. Evaluation of higher doses is needed to optimize treatment outcomes of TB and HIV in young children.

Safety and efficacy of rifabutin among HIV/TB-coinfected children on lopinavir/ritonavir-based ART.

BACKGROUND: TB is the leading cause of death among HIV-infected children, yet treatment options for those who require PI-based ART are suboptimal. Rifabutin is the preferred rifamycin for adults on PI-based ART; only one study has evaluated its use among children on PIs and two of six children developed treatment-limiting neutropenia. METHODS: Since 2009, rifabutin has been available for HIV/TB-coinfected children requiring PI-based ART in the Harvard/APIN programme in Nigeria. We retrospectively analysed laboratory and clinical toxicities at baseline and during rifabutin therapy, and examined HIV/TB outcomes. RESULTS: Between 2009 and 2015, 48 children received rifabutin-containing TB therapy with PI (lopinavir/ritonavir)-based ART: 50% were female with a median (IQR) baseline age of 1.7 (0.9-5.0) years and a median (IQR) CD4+ cell percentage of 15% (9%-25%); 52% were ART experienced. Eighty-five percent completed the 6 month rifabutin course with resolution of TB symptoms and 79% were retained in care at 12 months. Adverse events (grade 1-4) were more common at baseline (27%) than during rifabutin treatment (15%) (P = 0.006). Absolute neutrophil count was lower during rifabutin compared with baseline (median = 1762 versus 2976 cells/mm3, respectively), but only one instance (2%) of grade 3 neutropenia occurred during rifabutin treatment. CONCLUSIONS: With clinical and laboratory monitoring, our data suggest that rifabutin is a safe option for TB therapy among children on PI-based ART. By contrast with the only other study of this combination in children, severe neutropenia was rare. Furthermore, outcomes from this cohort suggest that rifabutin is effective, and a novel option for children who require PI-based ART. Additional study of rifabutin plus PIs in children is urgently needed.

Superior Effectiveness of Zidovudine Compared With Tenofovir When Combined With Nevirapine-based Antiretroviral Therapy in a Large Nigerian Cohort.

BACKGROUND: Despite sparse efficacy data, tenofovir-emtricitabine or tenofovir-lamivudine plus nevirapine is used in many resource-constrained settings. METHODS: This retrospective cohort study included patients initiating nevirapine-based antiretroviral therapy (ART) with either tenofovir-emtricitabine or lamivudine (tenofovir group) or zidovudine-lamivudine (zidovudine group). Clinical, virologic, and immunologic evaluations were performed at baseline and every 6 months. Virologic failure was defined as 2 consecutive human immunodeficiency virus (HIV)-RNA values >1000 copies/mL. Patients were included from ART initiation until time of failure, regimen switch, discontinuation, or last HIV-RNA measurement. Cox proportional hazards regression was used to model factors influencing time to failure. Bias due to dependent censoring was investigated via inverse probability weighted pooled logistic regression. RESULTS: A total of 5547 patients were evaluated; 1484 (26.8%) were in the tenofovir group and 4063 (73.2%) were in the zidovudine group. In the adjusted model, tenofovir regimen (hazard ratio [HR], 1.47; 95% confidence interval [CI], 1.21-1.79) and higher baseline log10 HIV-RNA (HR, 1.15; 95% CI, 1.03-1.28) were associated with virologic failure. Higher baseline log10 CD4+ cell count (HR, 0.50; 95% CI, .40-.63) and increasing age (HR, 0.98; 95% CI, .97-.99) decreased the risk of virologic failure. Inverse probability weighting results were consistent with the primary analysis. CONCLUSIONS: Compared with zidovudine-lamivudine, the use of tenofovir-lamivudine or emtricitabine in combination with nevirapine was a strong predictor of virologic failure in our cohort, which was not explained by other risk factors or criteria for regimen selection.

Pretreatment and Acquired Drug Resistance in Children With Human Immunodeficiency Virus Type 1 in Jos, Nigeria.

We determined pretreatment and acquired human immunodeficiency virus (HIV) drug resistance among children with HIV type 1 (HIV-1) in Jos, Nigeria. The majority (71%) of those who failed first-line antiretroviral therapy were on a nevirapine-containing regimen. The prevalence of pretreatment (48%) and acquired (76%) HIV drug resistance mutations was high in our study. Wider access to HIV drug resistance testing after treatment failure is necessary to optimize second-line treatment options among children with HIV in Nigeria.

Immunologic criteria are poor predictors of virologic outcome: implications for HIV treatment monitoring in resource-limited settings.

BACKGROUND: Viral load (VL) quantification is considered essential for determining antiretroviral treatment (ART) success in resource-rich countries. However, it is not widely available in resource-limited settings where the burden of human immunodeficiency virus infection is greatest. In the absence of VL monitoring, switches to second-line ART are based on World Health Organization (WHO) clinical or immunologic failure criteria. METHODS: We assessed the performance of CD4 cell criteria to predict virologic outcomes in a large ART program in Nigeria. Laboratory monitoring consists of CD4 cell count and VL at baseline, then every 6 months. Failure was defined as 2 consecutive VLs >1000 copies/mL after at least 6 months of ART. Virologic outcomes were compared with the 3 WHO-defined immunologic failure criteria. RESULTS: A total of 9690 patients were included in the analysis (median follow-up, 33.2 months). A total of 1225 patients experienced failure by both immunologic and virologic criteria, 872 by virologic criteria only, and 1897 by immunologic criteria only. The sensitivity of CD4 cell criteria to detect viral failure was 58%, specificity was 75%, and the positive-predictive value was 39%. For patients with both virologic and immunologic failure, VL criteria identified failure significantly earlier than CD4 cell criteria (median, 10.4 vs 15.6 months; P < .0001). CONCLUSIONS: Because of the low sensitivity of immunologic criteria, a substantial number of failures are missed, potentially resulting in accumulation of resistance mutations. In addition, specificity and predictive values are low, which may result in large numbers of unnecessary ART switches. Monitoring solely by immunologic criteria may result in increased costs because of excess switches to more expensive ART and development of drug-resistant virus.

Characterisation of HIV-1 Molecular Epidemiology in Nigeria: Origin, Diversity, Demography and Geographic Spread.

Nigeria has the highest number of AIDS-related deaths in the world. In this study, we characterised the HIV-1 molecular epidemiology by analysing 1442 HIV-1 pol sequences collected 1999-2014 from four geopolitical zones in Nigeria using state-of-the-art maximum-likelihood and Bayesian phylogenetic analyses. The main circulating forms were the circulating recombinant form (CRF) 02_AG (44% of the analysed sequences), CRF43_02G (16%), and subtype G (8%). Twenty-three percent of the sequences represented unique recombinant forms (URFs), whereof 37 (11%) could be grouped into seven potentially novel CRFs. Bayesian phylodynamic analysis suggested that five major Nigerian HIV-1 sub-epidemics were introduced in the 1960s and 1970s, close to the Nigerian Civil War. The analysis also indicated that the number of effective infections decreased in Nigeria after the introduction of free antiretroviral treatment in 2006. Finally, Bayesian phylogeographic analysis suggested gravity-like dynamics in which virus lineages first emerge and expand within large urban centers such as Abuja and Lagos, before migrating towards smaller rural areas. This study provides novel insight into the Nigerian HIV-1 epidemic and may have implications for future HIV-1 prevention strategies in Nigeria and other severely affected countries.

Pharmacokinetic interactions between ritonavir-boosted darunavir and NNRTIs: a report of 3 cases.

Pharmacokinetic interactions among antiretroviral agents may influence the potency or toxicity of coadministered drugs. Here we present 3 patients with extensive protease inhibitor and NRTI resistance for whom ritonavir-boosted darunavir (DRV/r) and an NNRTI were components of a successful antiretroviral regimen. These cases provide a context in which to review pharmacokinetic data pertaining to the coadministration of DRV/r and an antiretroviral agent from the NNRTI class. Although dose adjustments are not currently recommended when DRV/r is given in combination with any of the commonly prescribed NNRTIs, plasma levels of both darunavir and these NNRTIs are altered when they are used concomitantly. Understanding these pharmacokinetic changes might allow clinicians to predict which patients may be more vulnerable to adverse effects or inadequate antiviral activity caused by this drug interaction.

Distinct Pattern of Thymidine Analogue Mutations with K65R in Patients Failing Tenofovir-Based Antiretroviral Therapy.

Historically, in HIV patients, the K65R mutation and thymidine analogue mutations (TAMs) have been reported to rarely coexist. We retrospectively reviewed genotype data from paired samples in a cohort of HIV-1-infected Nigerian patients failing first-line antiretroviral therapies containing zidovudine (AZT) or tenofovir (TDF). Samples for each patient were taken at initial confirmed virological failure ≥1000 copies/ml (S1) and then at the latest available sample with viral load ≥1000 copies/ml before switch to second line (S2). Among 103 patients failing AZT, 19 (18.4%) had TAM-1s, 29 (28.2%) TAM-2s, and 21 (20.4%) mixed TAMs by S2. In contrast, in the 87 patients failing TDF, drug resistance mutations at S2 included K65R in 56 (64.4%), TAM-1s in 1 (1.1%), and TAM-2s in 25 patients (28.7%). Interestingly, 30.4% of patients with K65R in our study developed TAMs. These were exclusively K219E ± D67N and were not predicted to confer a resistance cost to future AZT-containing regimens.

Implication of First-Line Antiretroviral Therapy Choice on Second-Line Options.

BACKGROUND: Although there are a number of studies comparing the currently recommended preferred and alternative first-line (1L) antiretroviral therapy (ART) regimens on clinical outcomes, there are limited data examining the impact of 1L regimen choice and duration of virologic failure (VF) on accumulation of drug resistance mutations (DRM). The patterns of DRM from patients failing zidovudine (AZT)-containing versus tenofovir (TDF)-containing ART were assessed to evaluate the predicted susceptibility to second-line (2L) nucleoside reverse-transcriptase inhibitor (NRTI) backbone options in the context of an ongoing programmatic setting that uses viral load (VL) monitoring. METHODS: Paired samples from Nigerian ART patients who experienced VF and switched to 2L ART were retrospectively identified. For each sample, the human immunodeficiency virus (HIV)-1 polymerase gene was sequenced at 2 time points, and DRM was analyzed using Stanford University's HIVdb program. RESULTS: Sequences were generated for 191 patients. At time of 2L switch, 28.2% of patients on AZT-containing regimens developed resistance to TDF, whereas only 6.8% of patients on TDF-containing 1L had mutations compromising susceptibility to AZT. In a stratified evaluation, patients with 0-6 months between tested VL samples had no difference in proportion compromised to 2L, whereas those with >6 months between samples had a statistically significant difference in proportion with compromised 2L NRTI. In multivariate analyses, patients on 1L AZT had 9.90 times higher odds of having a compromised 2L NRTI option than patients on 1L TDF. CONCLUSIONS: In the context of constrained resources, where VL monitoring is limited, we present further evidence to support use of TDF as the preferred 1L NRTI because it allows for preservation of the recommended 2L NRTI option.

Patterns of Adherence and Loss to Follow-Up in Pediatric Patients on ART in Nigeria.

INTRODUCTION: High levels of adherence to antiretroviral therapy (ART) and retention in treatment programs are required for successful virologic suppression and treatment outcomes. While there have been numerous studies focusing on adherence and loss to follow-up (LTFU) in adults, studies in children and young adolescents are limited. For this study, we examined patterns of adherence and LTFU in HIV-infected pediatric patients receiving ART in PEPFAR-funded sites in Nigeria. METHODS: We conducted a retrospective observational study utilizing data that had been collected during the course of care in a large pediatric ART program in Nigeria. RESULTS: A total of 3,513 children ages 0-14.9 years enrolled at 31 different sites between June 2005 and March 2011 were included in the study. Of the enrolled patients, 1,987 (56%) were LTFU by the end of the study period. LTFU was highest in those ages<2 years and those≥13 years (versus aged 2-12.9 years). Year of ART initiation was a strong predictor of LTFU across all age groups. For those patients retained to 12 months, less than half showed optimal adherence (≥95%). While there were no differences in adherence rates at month 12 by age group, those aged 10 years and older did have declining adherence starting at 18 months. DISCUSSION: Adherence is critical for optimal ART patient outcomes. We found both low adherence and high LTFU rates in our study cohort. Additional studies focused on barriers to adherence and development of age-specific intervention programs are critical to improving overall pediatric outcomes.

Tuberculosis Incidence and Risk Factors Among Human Immunodeficiency Virus (HIV)-Infected Adults Receiving Antiretroviral Therapy in a Large HIV Program in Nigeria.

Background. Despite the benefits of antiretroviral therapy (ART), tuberculosis (TB) is the leading cause of mortality among human immunodeficiency virus (HIV)-infected persons in Africa. Nigeria bears the highest TB burden in Africa and second highest HIV burden globally. This long-term multicenter study aimed to determine the incidence rate and predictors of TB in adults in the Harvard/AIDS Prevention Initiative in Nigeria (APIN) and President's Emergency Plan for AIDS Relief (PEPFAR) Nigeria ART program. Methods. This retrospective evaluation used data collected from 2004 to 2012 through the Harvard/APIN PEPFAR program. Risk factors for incident TB were determined using multivariate Cox proportional hazards regression with time-dependent covariates. Results. Of 50 320 adults enrolled from 2005 to 2010, 11 092 (22%) had laboratory-confirmed active TB disease at ART initiation, and 2021 (4%) developed active TB after commencing ART. During 78 228 total person-years (PY) of follow-up, the TB incidence rate was 25.8 cases per 1000 PY (95% confidence interval [CI], 24.7-27.0) overall, and it decreased significantly both with duration on ART and calendar year. Risk factors at ART initiation for incident TB included the following: earlier ART enrollment year, tenofovir-containing initial ART regimen, and World Health Organization clinical stage above 1. Time-updated risk factors included the following: low body mass index, low CD4(+) cell count, unsuppressed viral load, anemia, and ART adherence below 80%. Conclusions. The rate of incident TB decreased with longer duration on ART and over the program years. The strongest TB risk factors were time-updated clinical markers, reinforcing the importance of consistent clinical and laboratory monitoring of ART patients in prompt diagnosis and treatment of TB and other coinfections.

Loss to Follow-Up within the Prevention of Mother-to-Child Transmission Care Cascade in a Large ART Program in Nigeria.

BACKGROUND: The 2013 WHO guidelines incorporated simplified and more effective antiretroviral regimens for the purposes of preventing mother-to-child transmission of HIV. With ideal implementation of these recommendations, perinatal HIV transmission could be reduced to less than 2%. However, loss to follow-up (LTFU) has the potential to erode the success of programs and a number of studies report high rates of LTFU within the prevention of mother-to-child transmission (PMTCT) care cascade. We evaluated the timing and magnitude of LTFU in a large programmatic PMTCT cohort in Nigeria in order to focus future efforts to reduce loss in this high burden setting. METHODS: From 2004-2014, the APIN/Harvard PEPFAR program supported antenatal HIV screening for nearly one million pregnant women and provided PMTCT care to over 30,000 women. The care cascade for women enrolling in the PMTCT program includes antenatal, delivery, and infant follow-up services through 12-18 months of life. In this retrospective cohort analysis, we examined data collected between 2004-2014 from 31 clinical sites in Nigeria and assessed the numbers of mothers and infants enrolled and LTFU at various points along the care cascade. RESULTS: Among 31,504 women (median age 30, IQR: 27-34) entering PMTCT care during the antenatal period, 20,679 (66%) completed the entire cascade of services including antenatal, delivery, and at least one infant follow-up visit. The median gestational age at presentation for antenatal care services was 23 weeks (IQR: 17-29). The median infant age at last follow-up visit was 12 months (IQR: 5-18). The greatest loss in the PMTCT care cascade occurred prior to delivery care (21%), with a further 16% lost prior to first infant visit. Of the 38,223 women who entered at any point along the PMTCT cascade, an HIV DNA PCR was available for 20,202 (53%) of their infants. Among infants for whom DNA PCR results were available, the rate of HIV transmission for infants whose mothers received any antenatal and/or delivery care was 2.8% versus 20.0% if their mother received none. CONCLUSION: In this large cohort analysis, the proportion of women LTFU in the PMTCT care cascade was lower than that reported in previous cohort analyses. Nevertheless, this proportion remains unacceptably high and inhibits the program from maximally achieving the goals of PMTCT care. We also provide the largest analysis to date on rates of perinatal HIV transmission, with low rates among women receiving NNRTI- or PI-based regimens, approaching that reported in clinical trials. However, among mothers who received any antenatal care, infant outcomes were unknown for 48%, and women presented later in pregnancy than that recommended by current guidelines. Implementation research to evaluate ways to improve integration of services, particularly transitions from antenatal to delivery and pediatric care, are critically needed to reduce LTFU within PMTCT programs and achieve the ultimate goal of eliminating pediatric HIV infection.

Time-Dependent Predictors of Loss to Follow-Up in a Large HIV Treatment Cohort in Nigeria.

BACKGROUND: Most evaluations of loss to follow-up (LTFU) in human immunodeficiency virus (HIV) treatment programs focus on baseline predictors, prior to antiretroviral therapy (ART) initiation. As risk of LTFU is a continuous issue, the aim of this evaluation was to augment existing information with further examination of time-dependent predictors of loss. METHODS: This was a retrospective evaluation of data collected between 2004 and 2012 by the Harvard School of Public Health and the AIDS Prevention Initiative in Nigeria as part of PEPFAR-funded program in Nigeria. We used multivariate modeling methods to examine associations between CD4(+) cell counts, viral load, and early adherence patterns with LTFU, defined as no refills collected for at least 2 months since the last scheduled appointment. RESULTS: Of 51 953 patients initiated on ART between 2004 and 2011, 14 626 (28%) were LTFU by 2012. Factors associated with increased risk for LTFU were young age, having nonincome-generating occupations or no education, being unmarried, World Health Organization (WHO) stage, having a detectable viral load, and lower CD4(+) cell counts. In a subset analysis, adherence patterns during the first 3 months of ART were associated with risk of LTFU by month 12. CONCLUSIONS: In settings with limited resources, early adherence patterns, as well as CD4(+) cell counts and unsuppressed viral load, at any time point in treatment are predictive of loss and serve as effective markers for developing targeted interventions to reduce rates of attrition.

Sputum smear concentration may misidentify acid-fast bacilli as Mycobacterium tuberculosis in HIV-infected patients.

BACKGROUND: Tuberculosis (TB) diagnosis in most resource-limited settings still depends on smear microscopy for identification of acid-fast bacilli (AFB). However, recently developed molecular diagnostics that test for the presence of Mycobacterium tuberculosis (Mtb) DNA have been shown to be superior for confirmation of TB diagnosis. METHODS: At regular clinical visits over a 12-month period, we collected sputa from HIV-infected patients presenting with signs or symptoms of TB at 2 Nigerian clinics. Sputa were stained for AFB and tested using the Genotype MTBDRplus to confirm the presence of Mtb. Other species were identified using 16S rRNA sequence. RESULTS: In 56% (233/415) of AFB-positive patients, Mtb was confirmed. The patients on antiretroviral therapy were less likely than those not on antiretroviral therapy to be infected with Mtb [odds ratio (OR) = 0.25, P = 0.003]. In a multivariate logistic regression model using clinical features and diagnostic results, abnormal respiratory findings on auscultation (OR = 3.28, P = 0.03) and a direct sputum smear grade >3/100 (OR = 6.4, 4.6, P < 0.02) were significant predictors of Mtb infection. Concentrated sputum smear was predictive of Mtb infection only at the highest grades (2+, 3+). Interestingly, among 65 samples that could not be confirmed for Mtb, 32 (49%) were found to contain other, possibly novel, actinomycetes, including atypical Mycobacteria, Rhodococcus spp, Nocardia spp, and Corynebacterium spp. CONCLUSIONS: We conclude that concentrated sputum smears may misidentify other bacteria as Mtb in HIV-infected patients. The use of molecular diagnostics could reduce unnecessary or inappropriate treatment and improve identification of pathogens in resource-limited settings with high HIV burden.

Accumulation of protease mutations among patients failing second-line antiretroviral therapy and response to salvage therapy in Nigeria.

BACKGROUND: To date, antiretroviral therapy (ART) guidelines and programs in resource-limited settings (RLS) have focused on 1(st)- and 2(nd)-line (2 L) therapy. As programs approach a decade of implementation, policy regarding access to 3(rd)-line (3 L) ART is needed. We aimed to examine the impact of maintaining patients on failing 2 L ART on the accumulation of protease (PR) mutations. METHODS AND FINDINGS: From 2004-2011, the Harvard/APIN PEPFAR Program provided ART to >100,000 people in Nigeria. Genotypic resistance testing was performed on a subset of patients experiencing 2 L failure, defined as 2 consecutive viral loads (VL)>1000 copies/mL after ≥6 months on 2 L. Of 6714 patients who received protease inhibitor (PI)-based ART, 673 (10.0%) met virologic failure criteria. Genotypes were performed on 61 samples. Patients on non-suppressive 2 L therapy for <12 months prior to genotyping had a median of 2 (IQR: 0-5) International AIDS Society (IAS) PR mutations compared with 5 (IQR: 0-6) among patients failing for >24 months. Patients developed a median of 0.6 (IQR: 0-1.4) IAS PR mutations per 6 months on failing 2 L therapy. In 38% of failing patients no PR mutations were present. For patients failing >24 months, high- or intermediate-level resistance to lopinavir and atazanavir was present in 63%, with 5% to darunavir. CONCLUSIONS: This is the first report assessing the impact of duration of non-suppressive 2 L therapy on the accumulation of PR resistance in a RLS. This information provides insight into the resistance cost of failing to switch non-suppressive 2 L regimens and highlights the issue of 3 L access.