Lower risk of resistance after short-course HAART compared with zidovudine/single-dose nevirapine used for prevention of HIV-1 mother-to-child transmission

Nevirapine plasma concentration is associated with virologic failure and the emergence of drug-resistant mutations among HIV patients in Kenya: A cross sectional study

This study aimed to determine the association between the plasma concentration of nevirapine (NVP) and clinical outcomes. In this cross-sectional study, sociodemographic and clinical data were collected from 233 HIV patients receiving NVP-based first-line antiretroviral therapy (ART) regimens in Nairobi, Kenya. The mean age was 41.2 (SD ± 11.9) years. Fifty-four (23.2%) patients had virological failure (>1000 copies/mL), whereas 23 (9.9%) were infected with drug-resistant HIV strains. Eleven patients had nucleoside reverse transcriptase inhibitor resistance mutations, including M184V and T215Y, whereas 22 had non-nucleoside reverse transcriptase inhibitor resistance mutations, including G190A, K103N, V106A, Y181C, A98G, and Y188L. The median NVP plasma concentration was 6180 ng/mL (IQR 4444-8843 ng/mL), with 38 (16.3%) patients having suboptimal NVP plasma levels of <3400 ng/mL. The majority 23 of the 38 (60.5%) patients with NVP Cmin < 3400 ng/mL were significantly infected with drug-resistant HIV virus (P = .001). In the multivariate analysis, the time taken to arrive at the ART clinic (β -11.1, 95% CI -21.2 to -1.1; P = .031), higher HIV viral load (β -2008, 95% CI -3370.7 to -645.3; P = .004), and the presence of HIV drug resistance mutation (β 3559, 95% CI 2580.8-4537.2; P = .0001) were associated with NVP plasma concentration. A significant proportion of patients receiving the NVP-based regimen had supra- and sub-therapeutic plasma concentrations. Higher HIV viral load and the presence of HIV drug-resistant mutations are important factors associated with NVP plasma concentrations.

Effects of cytochrome P450 2B6 and constitutive androstane receptor genetic variation on Efavirenz plasma concentrations among HIV patients in Kenya

The effects of genetic variation of cytochrome P450 2B6 (CYP2B6) and constitutive androstane receptor (CAR) on efavirenz (EFV) plasma concentration was evaluated among 312 HIV patients in Nairobi Kenya. The EFV plasma concentration at steady-state were determined using ultra-high-performance liquid chromatography with a tandem quadruple mass spectrometer (LC-MS/MS). Thirteen CYP2B6 (329G>T, 341T>C, 444 G>T/C, 15582C>T, 516G>T, 548T>G, 637T>C, 785A>G, 18492C>T, 835G>C, 1459C>T and 21563C>T) and one CAR (540C>T) single nucleotide polymorphisms (SNPs) were genotyped using real-time polymerase chain reaction. HIV drug resistance mutations were detected using an in-house genotypic assay. The EFV concentration of patients ranged from 4 ng/mL to 332697 ng/mL (median 2739.5 ng/mL, IQR 1878-4891.5 ng/mL). Overall, 22% patients had EFV concentrations beyond therapeutic range of 1000-4000 ng/mL (4.5%% < 1000 ng/mL and 31.7% > 4000 ng/mL). Five SNPs (15582C>T, 516G>T, 785A>G, 983T>C and 21563C>T) were associated with higher EFV plasma concentration while 18492C>T with lower EFV plasma concentration (p<0.05). Strong linkage disequilibrium (LD) was observed for 15582C>T, 516G>T, 785A>G, 18492C>T, 983T>C, 21563C>T, 1459C>T and CAR 540C>T. Sixteen haplotypes were observed and CTGCTTCC, CTGCTTCT, TTGCTTCT and CGACCCCT were associated with high EFV plasma concentration. In multivariate analysis, factors significantly associated with EFV plasma concentration included; the presence of skin rash (β = 1379, 95% confidence interval (CI) = 3216.9-3416.3; p < 0.039), T allele of CYP2B6 516G>T (β = 1868.9, 95% CI 3216.9-3416.3; p < 0.018), the C allele of CYP2B6 983T>C (β = 2638.3, 95% CI = 1348-3929; p < 0.0001), T allele of CYP2B6 21563C>T (β = 1737, 95% CI = 972.2-2681.9; p < 0.0001) and the presence of 5 to 7 numbers of SNPs per patient (β = 570, 95% CI = 362-778; p < 0.0001) and HIV viral load ≤1000 cells/mL (β = -4199.3, 95% CI = -7914.9 --483.6; p = 0.027). About 36.2% of the patients had EFV plasma concentrations beyond therapeutic window, posing high risk of treatment failure or toxicity. The SNPs of CYP2B6 516G>T, CYP2B6 983T>C, 21563C>T, presence of higher numbers of SNPs per patient and haplotypes CTGCTTCC, CTGCTTCT, TTGCTTCT and CGACCCCT could efficiently serves as genetic markers for EFV plasma concentration and could guide personalization of EFV based ART treatment in Kenya.

Prevalence and Factors Associated With Virological Treatment Failure Among Children and Adolescents on Antiretroviral Therapy Attending HIV/AIDS Care and Treatment Clinics in Dodoma Municipality, Central Tanzania

BACKGROUND

As the World Health Organization (WHO) and its joint partners such as USAIDS target achieving 90% sustained virological suppression among children and adolescents living with Human Immunodeficience Virus (HIV)/AIDS, it is imperative to elucidate the current prevalence and factors associated with virological treatment failure for formulation of appropriate strategies. This study was conducted determine the prevalence and factors associated with virological treatment failure among children and adolescents with HIV/AIDS on antiretroviral therapy (ART) attending HIV/AIDS care clinics in Dodoma, Central Tanzania.

METHODS

This was a cross-sectional study of children aged 1-19 years attending 3 HIV/AIDS care clinics in Dodoma (central Tanzania) from November 2018 to February 2019. Sociodemographic and clinical factors were documented, HIV viral load and CD4+ T lymphocytes were evaluated for children on ART for ≥6 months. The primary outcomes were the prevalence and factors associated with viralogic treatment failure.

RESULTS

Of 300 children enrolled, 102 (34%) had virological treatment failure. Poor adherence to ART (adjusted odds ratio [AOR] = 3.221; 95% confidence interval [CI], 1.867-5.558; P = .032), nevirapine regimen (AOR = 3.185; 95% CI, 1.473-6.886; P ≤ .001), not using cotrimoxazole prophylaxis (AOR = 25.56; 95% CI, 3.15-27.55; P = .002) and nondisclosure of HIV status to others (AOR = 7.741; 95% CI, 2.351-25.489; P = .001) were independently associated with virological treatment failure.

CONCLUSIONS

Current prevalence of virological treatment failure among children and adolescents living with HIV on ART remain high. Factors such as ART adherence, nevirapine based regimen, HIV status disclosure to those caring for the child need to be addressed to achieve sustained virological suppression.

High Viremia and Wasting Before Antiretroviral Therapy Are Associated With Pneumonia in Early-Treated HIV-Infected Kenyan Infants

BACKGROUND

Human immunodeficiency virus (HIV)-infected children are particularly susceptible to acute respiratory infections (ARIs). We determined incidence and cofactors for ARIs in HIV-infected infants receiving antiretroviral therapy (ART).

METHODS

Human immunodeficiency virus-infected infants initiated ART at ≤12 months of age and were observed monthly for 2 years in Nairobi. Acute respiratory infection rates and cofactors were determined using Andersen-Gill models, allowing for multiple events per infant.

RESULTS

Among 111 HIV-infected infants, median age at ART initiation was 4.5 months. Pre-ART median CD4% was 19%, and 29% had wasting. During 24-months follow-up while on ART, upper respiratory infection (URI) and pneumonia rates were 122.6 and 34.7 per 100 person-years (py), respectively. Infants with higher pre-ART viral load (VL) (plasma HIV ribonucleic acid [RNA] ≥7 log10 copies/mL) had 4.12-fold increased risk of pneumonia (95% confidence interval [CI], 2.17-7.80), and infants with wasting (weight-for-height z-score < -2) had 2.87-fold increased risk (95% CI, 1.56-5.28). Infants with both high pre-ART VL and wasting had a higher pneumonia rate (166.8 per 100 py) than those with only 1 of these risk factors (44.4 per 100 py) or neither (17.0 per 100 py). Infants with exposure to wood fuel had significantly higher risk of URI (hazard ratio [HR] = 1.82; 95% CI, 1.44-2.28) and pneumonia (HR = 3.31; 95% CI, 1.76-6.21).

CONCLUSIONS

In early ART-treated HIV-infected infants, higher HIV RNA and wasting before ART were independent risk factors for pneumonia. Wood fuel use was associated with URI and pneumonia. Additional data on air pollution and respiratory outcomes in HIV-infected children may help optimize interventions to improve their lung health.

Genital Shedding of Resistant Human Immunodeficiency Virus-1 Among Women Diagnosed With Treatment Failure by Clinical and Immunologic Monitoring

Detection of resistant HIV-1 in genital secretions of women failing first-line therapy was associated with a greater number of resistance mutations in plasma. While genital resistance emerged later than plasma resistance, genital shedding could increase risk for transmitted drug resistance.

Background. The accumulation of human immunodeficiency virus (HIV) resistance mutations can compromise treatment outcomes and promote transmission of drug-resistant virus. We conducted a study to determine the duration and evolution of genotypic drug resistance in the female genital tract among HIV-1-infected women failing first-line therapy.

Methods. Treatment failure was diagnosed based on World Health Organization (WHO) clinical or immunologic criteria, and second-line therapy was initiated. Stored plasma and genital samples were tested to determine the presence and timing of virologic failure and emergence of drug resistance. The median duration of genital shedding of genotypically resistant virus prior to regimen switch was estimated.

Results. Nineteen of 184 women were diagnosed with treatment failure, of whom 12 (63.2%) had confirmed virologic failure at the switch date. All 12 women with virologic failure (viral load, 5855–1 086 500 copies/mL) had dual-class resistance in plasma. Seven of the 12 (58.3%) had genital HIV-1 RNA levels high enough to amplify (673–116 494 copies/swab), all with dual-class resistance. The median time from detection of resistance in stored samples to regimen switch was 895 days (95% confidence interval [CI], 130–1414 days) for plasma and 629 days (95% CI, 341–984 days) for genital tract secretions.

Conclusions. Among women diagnosed with treatment failure using WHO clinical or immunologic criteria, over half had virologic failure confirmed in stored samples. Resistant HIV-1 RNA was shed in the genital tract at detectable levels for ≈1.7 years before failure diagnosis, with steady accumulation of mutations. These findings add urgency to the ongoing scale-up of viral load testing in resource-limited settings.

HIV-1 protease inhibitor drug resistance in Kenyan antiretroviral treatment-naive and -experienced injection drug users and non-drug users

BACKGROUND

Although injection drug use drives antiretroviral drug resistance, the prevalence of protease inhibitor (PI) resistance among Kenyan IDUs remains undetermined. We, therefore, explored PI resistance mutations and their association with viral load and CD4+ T cell counts in HIV-1 infected IDUs (ART-naive, n = 32; and -experienced, n = 47) and non-drug users (ART-naive, n = 21; and -experienced, n = 32) naive for PI treatment from coastal Kenya.

RESULTS

Only IDUs harboured major PI resistance mutations consisting of L90M, M46I and D30 N among 3 (6.4 %) ART-experienced and 1 (3.1 %) -naive individuals. Minor PI mutations including A71T, G48E, G48R, I13V, K20I, K20R, L10I, L10V, L33F, L63P, T74S, V11I, and V32L were detected among the ART-experienced (36.2 vs. 46.9 %) and -naive (43.8 vs. 66.7 %) IDUs and non-drug users, respectively. All the four IDUs possessing major mutations had high viral load while three presented with CD4+ T cell counts of <500 cells/ml. Among the ART-naive non-drug users, CD4+ T cell counts were significantly lower in carriers of minor mutations compared to non-carriers (P < 0.05).

CONCLUSION

Transmitted drug resistance may occur in IDUs underscoring the need for genotyping resistance before initiating PI treatment.

Nevirapine Resistance in Previously Nevirapine-Unexposed HIV-1-Infected Kenyan Infants Initiating Early Antiretroviral Therapy

Nevirapine (NVP) resistance occurs frequently in infants following NVP use in prevention of mother-to-child transmission (PMTCT) regimens. However, among previously NVP-unexposed infants treated with NVP-antiretroviral therapy (ART), the development and impact of NVP resistance have not been well characterized. In a prospective clinical trial providing early ART to HIV-infected infants <5 months of age in Kenya (OPH03 study), we followed NVP-unexposed infants who initiated NVP-ART for 12 months. Viral loads were assessed and resistance determined using a population-based genotypic resistance assay. Of 99 infants screened, 33 had no prior NVP exposure, 22 of whom were initiated on NVP-ART. Among 19 infants with follow-up, seven (37%) infants developed resistance: one at 3 months and six at 6 months after ART initiation. The cumulative probability of NVP resistance was 5.9% at 3 months and 43.5% at 6 months. Baseline HIV RNA levels (p=0.7) and other characteristics were not associated with developing resistance. Post-ART, higher virus levels at visits preceding the detection of resistance were significantly associated with increased detection of resistance (p=0.004). Virus levels after 6 and 12 months of ART were significantly higher in infants with resistance than those without (p=0.007, p=0.030, respectively). Among infants without previous NVP exposure, development of NVP resistance was frequent and was associated with virologic failure during the first year of ART. Earlier development of NVP resistance in infants than in adults initiating NVP-ART may be due to longer viremia following ART or inadequate NVP levels resulting from NVP lead-in dosing. The development of NVP resistance may, in part, explain the superiority of protease inhibitor-based ART in infants.

HIV type 1 drug resistance patterns among patients failing first and second line antiretroviral therapy in Nairobi, Kenya

BACKGROUND

The ever-expanding rollout of antiretroviral therapy in poor resource settings without routine virological monitoring has been accompanied with development of drug resistance that has resulted in limited treatment success.

METHODS

A cross-sectional study with one time viral load was conducted during the period between 2012 and 2013 to determine treatment failure and drug resistance mutations among adults receiving first-line (44) (3TC_d4T/AZT_NVP/EFV) and second-line (20) (3TC/AZT/LPV/r) in Nairobi, Kenya. HIV-1 pol-RT genotyping for drug resistance was performed using an in-house protocol.

RESULTS

A total of 64 patients were recruited (mean age 36.9 yrs.) during the period between 2012 and 2013 of the 44 adult patients failing first-line 24 (40.9%) had drug resistance mutations. Eight (8) patients had NRTI resistance mutations with NAMS M184V (54.2%) and K65R (8.4%) mutations being the highest followed by TAMs T215Y and K70R (12.5%). In addition, among patients failing second-line (20), six patients (30%) had NNRTI resistance; two patients on K103N and G190A mutations while V106A, Y184V, A98G, Y181C mutations per patient were also detected. However, for NRTI two patients had TAM T215Y. M184V mutation occurred in one patient.

CONCLUSIONS

The study findings showed that HIV-1 drug resistance was significantly high in the study population. The detected accumulated resistance strains show that emergence of HIV drug resistance will continue to be a big challenge and should be given more attention as the scale up of treatment in the country continues.

Does the national program of prevention of mother to child transmission of HIV (PMTCT) reach its target in Ouagadougou, Burkina Faso?

BACKGROUND

In the context of universal access to prevention, treatment, care and support, each country has to ensure that 80% of women and children in need have access to PMTCT interventions.

OBJECTIVE

To assess the PMTCT program achievement in Ouagadougou, the capital city of Burkina Faso.

METHODS

Between August and October 2008, a cross sectional study was carried out in the five health districts of the Centre Health Region. We reviewed weekly statistics from all health care centres (HCC) to compute the coverage of PMTCT program. In 38 HCC with functional PMTCT program, we extracted data of interest from HCC registers and made direct observations of PMTCT services.

RESULTS

The PMTCT program was implemented in 49% of HCC (target for the national program: 70%). Fifteen to 31% of these centers were often in shortage for PMTCT consumables. Patients' privacy was not observed in 67% of Voluntary Counselling & HIV Testing wards. Care providers were not qualified enough to deliver PMTCT services. Vitamin A supplementation was not implemented. None of the facilities offered the whole package of PMTCT program interventions. HCC providing HIV testing in labour or in postnatal ward were consistently lacking. Only 86% of antenatal care new attendants benefited from pre-test counselling; 2.4% of pretested women were HIV-positive and 39% of positive mothers received antiretroviral prophylaxis.

CONCLUSION

Coverage and quality of PMTCT programme in the Centre Health Region in Burkina Faso are still limited. Particular support is needed for training, supervision and infrastructures upgrading.

Antiretroviral drugs for prevention of mother-to-child transmission: pharmacologic considerations for a public health approach

OBJECTIVE

Efavirenz-based antiretroviral therapy is recommended for prevention of mother-to-child transmission of HIV with two programmatic options: lifelong therapy for all women or treatment until cessation of breastfeeding. However, the risk of HIV resistance emerging after discontinuing efavirenz-based antiretroviral therapy is unclear. We review present knowledge surrounding the emergence of resistance after stopping efavirenz-based antiretroviral regimens.

DESIGN

An expert review.

METHODS

A literature review was conducted to identify studies assessing risk for emergence of efavirenz-related resistance following discontinuation of efavirenz-based antiretroviral regimens containing either lamivudine and zidovudine or tenofovir disoproxil fumarate and lamivudine. Discontinuation strategies including the use of 'pharmacologic tails' are discussed in the light of what is known about the pharmacology of the drugs.

RESULTS

We found no head-to-head comparisons between zidovudine, lamivudine and efavirenz and tenofovir disoproxil fumarate, lamivudine and efavirenz. The risk for HIV resistance exists, even with a 5-7 day tail of zidovudine and lamivudine. For tenofovir disoproxil fumarate, lamivudine and efavirenz, we found no clinical data to inform a recommendation for a tail.

CONCLUSION

In order to prevent emergence of resistance, a tail of at least 2 weeks in duration may be required when discontinuing efavirenz in a regimen containing zidovudine and lamivudine. Studies are needed to characterize the risk of resistance among women who discontinue tenofovir disoproxil fumarate, lamivudine and efavirenz.

Antiretroviral interventions for preventing breast milk transmission of HIV

BACKGROUND

An estimated 260,000 children under the age of 15 years acquired HIV infection in 2012. As much as 42% of mother-to-child transmission is related to breastfeeding. Antiretroviral prophylaxis for mothers or infants has the potential to prevent mother-to-child transmission of HIV through breast milk.

OBJECTIVES

To determine which antiretroviral prophylactic regimens are efficacious and safe for reducing mother-to-child transmission of HIV through breastfeeding and thereby avert child morbidity and mortality.

SEARCH METHODS

Using Cochrane Collaboration search methods in conjunction with appropriate search terms, we identified relevant studies from January 1, 1994 to January 14, 2014 by searching databases including Cochrane CENTRAL, EMBASE and PubMed, LILACS, and Web of Science/Web of Social Science.

SELECTION CRITERIA

Randomized controlled trials in which HIV-infected mothers breastfed their infants, and in which the mothers used antiretroviral prophylaxis while breastfeeding their children or their children received antiretroviral prophylaxis for at least four weeks while breastfeeding, were included.

DATA COLLECTION AND ANALYSIS

Abstracts of all trials identified were examined independently by two authors. We identified 15,922 references and examined 81 in detail. Data were abstracted independently using a standardized form.

MAIN RESULTS

Seven RCTs were included in the review.One trial compared triple antiretroviral prophylaxis during pregnancy and breastfeeding with short antiretroviral prophylaxis to given to the mother to prevent mother-to-child transmission of HIV. At 12 months, the risks of HIV transmission, and of HIV transmission or death, were lower, but there was no difference in infant mortality alone in the triple arm versus the short arm. Using the GRADE methodology, evidence quality for outcomes in this trial was generally low to moderate.One trial compared six months of breastfeeding using zidovudine, lamivudine, and lopinavir/ritonavir versus zidovudine, lamivudine, and abacavir from 26-34 weeks gestation. At six months, there was no difference in risk of infant HIV infection, infant death, or infant HIV infection or death between the two groups. Evidence quality for outcomes in this trial was generally very low to low.One trial of single dose nevirapine versus six weeks of infant zidovudine found the risk of HIV infection at 12 weeks to be greater in the zidovudine arm than in the single dose nevirapine arm. Evidence quality for outcomes in this trial was generally very low.One multi-country trial compared single dose nevirapine and six weeks of infant nevirapine. After 12 months, infants in the extended nevirapine group had a lower risk of infant mortality compared with the control. There was no difference in the risk of HIV infection or death or in HIV transmission alone in the extended nevirapine group compared with the control. Evidence quality for outcomes in this trial was generally low to moderate.One trial compared single dose nevirapine plus one week zidovudine; the control regimen plus nevirapine up to 14 weeks; or the control regimen with dual prophylaxis up to 14 weeks. At 24 months, the extended nevirapine regimen group had a lower risk of HIV transmission and of HIV transmission or death vs. the control. There was no difference in infant mortality alone. Compared with controls, the dual prophylaxis group had a lower risk of HIV transmission and of HIV transmission or death, but no difference in infant mortality alone. There was no difference in these outcomes between the two intervention arms. Evidence quality for outcomes in this trial was generally moderate to high.One trial compared six weeks of nevirapine with six months of nevirapine. Among infants of mothers not using highly active antiretroviral therapy, there was no difference in risk of HIV infection among the six month nevirapine group versus the six week nevirapine group. Evidence quality for outcomes in this trial was generally low to moderate.One trial compared a maternal triple-drug antiretroviral regimen, infant nevirapine, or neither intervention. Infants in the maternal prophylaxis arm were at lower risk for HIV, and HIV infection or death when compared with the control group. There was no difference in the risk of infant mortality alone. Infants with extended prophylaxis had a lower risk of HIV infection and of HIV infection or death versus the control group infants. There was no difference in the risk of infant mortality alone in the extended infant nevirapine group versus the control. There was no difference in HIV infection, infant mortality, and HIV infection or death between the maternal and extended infant prophylaxis groups. Evidence quality for outcomes in this trial was generally low to moderate.

AUTHORS' CONCLUSIONS

Antiretroviral prophylaxis, whether used by the HIV-infected mother or the HIV-exposed infant while breastfeeding, is efficacious in preventing mother-to-child transmission of HIV. Further research is needed regarding maternal resistance and response to subsequent antiretroviral therapy after maternal prophylaxis. An ongoing trial (IMPAACT 1077BF) compares the efficacy and safety of maternal triple antiretroviral prophylaxis versus daily infant nevirapine for prevention of mother-to-child transmission through breastfeeding.

No clinically significant drug-resistance mutations in HIV-1 subtype C-infected women after discontinuation of NRTI-based or PI-based HAART for PMTCT in Botswana

Risk of developing drug resistance after stopping antiretroviral regimens to prevent mother-to-child HIV-1 transmission is unknown. The Mma Bana Study randomized treatment-naive pregnant women with CD4 ≥200 cells per cubic millimeter to receive either abacavir/zidovudine/lamivudine [triple nucleoside reverse transcriptase inhibitor (NRTI) arm] or lopinavir/ritonavir/zidovudine/lamivudine [protease inhibitor (PI) arm]. Drugs were discontinued after 6 months of breastfeeding. One month after discontinuation, 29 NRTI arm samples and 25 PI arm samples were successfully genotyped. No clinically significant antiretroviral resistance mutations were detected. Eight minor resistance mutations were found among 11 (20%) women (3 from NRTI arm and 8 from PI arm), occurring at similar frequencies to those reported in HIV-1 subtype C treatment-naive cohorts.

Long-term virologic response and genotypic resistance mutations in HIV-1 infected Kenyan children on combination antiretroviral therapy

BACKGROUND

HIV-infected children may require the use of combination antiretroviral treatment (cART) into adulthood. However, regimens are limited to first line and second line in many African settings. Therefore, understanding the long-term rate of virologic failure and drug resistance during prolonged antiretroviral treatment is important for establishing treatment strategies in African pediatric cohorts.

METHODS

Children aged 18 months to 12 years initiated first-line cART and were followed every 1-3 months, for up to 5.5 years. Treatment was switched to second-line cART based on clinical and immunologic criteria according to national guidelines. Virologic failure was determined retrospectively as defined by ≥2 viral loads >5000 copies per milliliter. Drug resistance was assessed during viral failure by population-based sequencing.

RESULTS

Among 100 children on first-line cART followed for a median of 49 months, 34% children experienced virologic failure. Twenty-three (68%) of the 34 children with viral failure had detectable resistance mutations, of whom 14 (61%) had multiclass resistance. Fourteen (14%) children were switched to second-line regimens and followed for a median of 28 months. Retrospective analysis revealed that virologic failure had occurred at a median of 12 months before switching to second line. During prolonged first-line treatment in the presence of viral failure, additional resistance mutations accumulated; however, only 1 (7%) of 14 children had persistent viremia during second-line treatment.

DISCUSSION

Virologic suppression was maintained on first-line cART in two-thirds of HIV-infected children for up to 5 years. Switch to second line based on clinical/immunologic criteria occurred ∼1 year after viral failure, but the delay did not consistently compromise second-line treatment.

Impact of antiretroviral drugs in pregnant women and their children in Africa: HIV resistance and treatment outcomes

The global community has committed itself to eliminating new pediatric HIV infections by 2015 and improving maternal, newborn, and child health and survival in the context of HIV. Such objectives require regimens to prevent mother-to-child transmission (pMTCT) which, while being highly efficacious, protect the efficacy of future first-line antiretroviral therapy (ART). Major obstacles to eliminating vertical transmissions globally include low rates of adherence to ART and non-completion of the 'pMTCT cascade' due to programmatic and structural challenges faced by healthcare systems in low-income countries. Providing all pregnant women with lifelong ART regardless of CD4 count/disease stage (Option B+) could be the most effective option to prevent both HIV transmission and resistance, assuming adherence is successfully maintained. This strategy is more likely to achieve sustained undetectable HIV viremia, does not involve ART interruptions, is simpler to implement, and is cost-effective. Where Option B+ is not available, options A (short course zidovudine with single-dose nevirapine and an ARV "tail") and B (combination ART during pregnancy and breastfeeding, with ART cessation after weaning in women not qualifying for ART for their own health) are also efficacious, highly cost-effective and associated with infrequent resistance selection if taken properly.

Economic evaluation of 3-drug antiretroviral regimens for the prevention of mother-to-child HIV transmission in Thailand

The current program for prevention of mother-to-child HIV transmission in Thailand recommends a 2-drugs regimen for HIV-infected pregnant women with a CD4 count >200 cells/mm(3). This study assesses the value for money of 3 antiretroviral drugs compared with zidovudine (AZT)+single-dose nevirapine (sd-NVP). A decision tree was constructed to predict costs and outcomes using the governmental perspective for assessing cost-effectiveness of 3-drug regimens: (1) AZT, lamivudine, and efavirenz and (2) AZT, 3TC, and lopinavir/ritonavir, in comparison with the current protocol, AZT+sd-NVP. The 3-drug antiretroviral regimens yield lower costs and better health outcomes compared with AZT+sd-NVP. Although these 3-drug regimens offer higher program costs and health care costs for premature birth, they save money significantly in regard to pediatric HIV treatment and treatment costs for drug resistance in mothers. The 3-drug regimens are cost-saving interventions. The findings from this study were used to support a policy change in the national recommendation.

Clinical and genetic determinants of plasma nevirapine exposure following an intrapartum dose to prevent mother-to-child HIV transmission

OBJECTIVE

Nevirapine is metabolized by cytochrome P450 (CYP) 2B6 and CYP3A4. We characterized relationships between clinical parameters, human genetics, pharmacokinetics, and human immunodeficiency virus type 1 (HIV-1) drug resistance mutations in pregnant women following single-dose intrapartum nevirapine.

METHODS

In AIDS Clinical Trials Group study A5207, women received nevirapine at onset of labor and were randomly assigned to receive lamivudine/zidovudine, emtricitabine/tenofovir, or lopinavir/ritonavir for 7 or 21 days. Plasma nevirapine level was quantified on postpartum day 1 and on weeks 1, 3, and 5. We assayed 214 polymorphisms in CYP2B6 and other genes and evaluated associations with pharmacokinetic parameters, including elimination constant, time to protein-adjusted 50% inhibitory concentration (IC50), and week 5 nevirapine level below the quantification limit.

RESULTS

Among 301 women with evaluable pharmacokinetic and genotype data, lower body mass index and random assignment to receive lopinavir/ritonavir were associated with more rapid nevirapine elimination. Among those of African ancestry, longer time to IC50 was associated with CYP2B6 983T → C (P = .004) but not with CYP2B6 516G → T (P = .8). Among Indians, slower nevirapine elimination was associated with CYP2B6 516G → T (P = .04). Emergent resistance was infrequent and not associated with pharmacokinetics or CYP2B6 genotype.

CONCLUSIONS

The effects on plasma drug exposure following single-dose nevirapine may be greater for CYP2B6 983T → C than for 516G → T and are less pronounced than at steady state.

Antiretroviral treatment interruptions predict female genital shedding of genotypically resistant HIV-1 RNA

OBJECTIVES

Resistant viruses may emerge in the female genital tract during antiretroviral therapy (ART). Our objective was to identify predictors of drug-resistant HIV-1 RNA in genital secretions after initiation of nonnucleoside reverse transcriptase inhibitor-based therapy.

DESIGN

We conducted a prospective cohort study with periodic evaluation of plasma and genital swab samples for HIV-1 RNA levels and antiretroviral resistance mutations.

METHODS

First-line ART was initiated in 102 women. Plasma and genital HIV-1 RNA levels were measured at months 0, 3, 6, and 12. Genotypic resistance testing was performed for samples from all participants with RNA >1000 copies per milliliter at month 6 or 12. Cox regression analysis was used to identify factors associated with incident genital tract resistance.

RESULTS

Detectable genital tract resistance developed in 5 women, all with detectable plasma resistance (estimated incidence, 5.5/100 person-years of observation). Treatment interruption >48 hours, adherence by pill count, adherence by visual analog scale, and baseline plasma viral load were associated with incident genital tract resistance. In multivariate analysis, only treatment interruption was associated with risk of detectable genital tract resistance (adjusted hazard ratio: 14.2; 95% confidence interval: 1.3 to 158.4).

CONCLUSIONS

Treatment interruption >48 hours during nonnucleoside reverse transcriptase inhibitor-based therapy led to a significantly increased risk of detecting genotypically resistant HIV-1 RNA in female genital tract secretions. Patient- and program-level interventions to prevent treatment interruptions could reduce the risk of shedding-resistant HIV-1 during ART.

Low-frequency nevirapine resistance at multiple sites may predict treatment failure in infants on nevirapine-based treatment

BACKGROUND

Resistance commonly arises in infants exposed to single-dose nevirapine (sdNVP) for prevention of mother to child transmission. Although K103N and Y181C are common following sdNVP, multiple other mutations also confer NVP resistance. It remains unclear whether specific NVP resistance mutations or combinations of mutations predict virologic failure in infants when present at low frequencies before NVP-based treatment.

METHODS

Twenty sdNVP-exposed infants who were subsequently treated with NVP-based highly active antiretroviral therapy were examined. Pretreatment plasma samples were tested for the presence of NVP resistance mutations by allele-specific polymerase chain reaction for K103N and Y181C and ultradeep pyrosequencing (UDPS) for all primary NVP mutations. Viral levels were determined every 3 months for up to 24 months on NVP-highly active antiretroviral therapy. Cox proportional hazard models were used to determine correlates of viral failure.

RESULTS

The NVP resistance mutations K103N or Y181C were detected in pretreatment plasma samples in 6 infants by allele-specific polymerase chain reaction. NVP resistance at these or other sites was detectable by UDPS in 10 of 20 infants tested. Virologic failure occurred in 50% of infants with any NVP resistance mutations detected, whereas only 20% of infants without resistance experienced viral failure, but the difference was not significant (P = 0.19). An increase in the number of NVP resistance mutations detectable by UDPS in an infant was significantly associated with an increased risk of virologic failure [HR = 1.79 (95% confidence interval: 1.07 to 2.99), P = 0.027].

CONCLUSIONS

Low frequencies of multiple NVP resistance mutations, in addition to K103N and Y181C, present in infants before NVP-based treatment may predict treatment outcome.

Effects of short-course zidovudine on the selection of nevirapine-resistant HIV-1 in women taking single-dose nevirapine

Single-dose nevirapine (sdNVP) given to prevent mother-to-child-transmission of HIV-1 selects NVP-resistance. Short-course zidovudine (ZDV) was hypothesized to lower rates of NVP-resistance. HIV-1 infected pregnant women administered sdNVP with or without short-course ZDV were assessed for HIV-1 mutations (K103N, Y181C, G190A, and V106M) prior to delivery and postpartum. Postpartum NVP-resistance was lower among 31 taking ZDV+sdNVP compared to 33 taking only sdNVP (35.5% vs. 72.7%; χ2 P = .003). NVP mutants decayed to <2% in 24/35 (68.6%) at a median 6 months postpartum, with no differences based on ZDV use (logrank P = .99). Short-course ZDV was associated with reduced NVP-resistance mutations among women taking sdNVP.

Acceptability and feasibility of integration of HIV care services into antenatal clinics in rural Kenya: a qualitative provider interview study

The aim of this study was to explore the perspectives of healthcare providers on the advantages and disadvantages of integrating HIV care services, including highly active antiretroviral therapy (HAART), into antenatal care (ANC) clinics in rural Kenya. We conducted a qualitative study using in-depth interviews and thematic analysis; 36 healthcare providers from six health centres in Nyanza Province, Kenya participated. Effects on service providers included increased workload due to the incorporation of specialised HIV services into ANC clinics. Providers observed that integration results in decreased patient time spent at the health facility, increased efficiency and closer provider-patient relationships; all leading to increased patient satisfaction. Providers also said that women would be more likely to receive HAART and adhere to their treatment as a result of improved confidentiality and decreased stigma. However, a minority of providers noted that integration could result in longer appointment times for HIV-positive women at ANC clinics leading to inadvertent disclosure. Integration could lead to strengthened ANC, postpartum care, prevention of mother-to-child transmission and HIV care for women and their families. However, integration efforts need to take into account potential negative effects on ANC provider workload, disclosure and the quality of care.

Emergence and persistence of minor drug-resistant HIV-1 variants in Ugandan women after nevirapine single-dose prophylaxis

Background

Nevirapine (NVP) single-dose is still a widely used antiretroviral prophylaxis for the prevention of vertical HIV-1 transmission in resource-limited settings. However, the main disadvantage of the Non-nucleoside Reverse Transcriptase Inhibitor (NNRTI) NVP is the rapid selection of NVP-resistant virus with negative implications for subsequent NNRTI-based long-term antiretroviral therapy (ART). Here, we analysed the emergence of drug-resistant HIV-1 including minor variants in the early phase after NVP single-dose prophylaxis and the persistence of drug-resistant virus over time.

Methods and Findings

NVP-resistant HIV-1 harbouring the K103N and/or Y181C resistance mutations in the HIV-1 reverse transcriptase gene was measured from 1 week up to 18 months after NVP single-dose prophylaxis in 29 Ugandan women using allele-specific PCR assays capable of detecting drug-resistant variants representing less than 1% of the whole viral population. In total, drug-resistant HIV-1 was identified in 18/29 (62%) women; rates increased from 18% to 38% and 44% at week 1, 2, 6, respectively, and decreased to 18%, 25%, 13% and 4% at month 3, 6, 12 and 18, respectively. The proportion of NVP-resistant virus of the total viral population was significantly higher in women infected with subtype D (median 40.5%) as compared to subtype A (median 1.3%; p = 0.032, Mann-Whitney U test). 33% of resistant virus was not detectable at week 2 but was for the first time measurable 6–12 weeks after NVP single-dose prophylaxis. Three (10%) women harboured resistant virus in proportions >10% still at month 6.

Conclusions

Current WHO guidelines recommend an additional postnatal intake of AZT and 3TC for one week to avoid NVP resistance formation. Our findings indicate that a 1-week medication might be too short to impede the emergence of NVP resistance in a substantial proportion of women. Furthermore, subsequent NNRTI-based ART should not be started earlier than 12 months after NVP single-dose prophylaxis.

Prevention of vertical transmission of HIV-1 in resource-limited settings

One of the most exciting areas of HIV research is that of prevention of vertical transmission from mother to child, since it accounts for 90% of childhood HIV infections, and therefore prevention in this context has an enormous potential impact on the spread of HIV among children. Focused research has yielded highly successful strategies for reducing infant infection rates, particularly in the developed world, and much work is underway to implement appropriate strategies in resource-limited settings, although this is not without challenges. Although transmission rates in some settings have been reduced to approximately 1%, scale-up and widespread implementation and application of strategic interventions for prevention of mother-to-child transmission of HIV during pregnancy, delivery and breastfeeding are needed in the developing world.

Advances in prevention of mother-to-child HIV transmission: the international perspectives

We have sufficient knowledge and unprecedented access to global resources to dramatically reduce the transmission of HIV-1 from mother to children worldwide. Most transmission occurs during delivery and after birth through breastfeeding. For this reason, efforts to interrupt transmission have focused on peripartum period and safe infant feeding. This includes the use of antiretroviral therapy, elective cesarean section, avoidance of breastfeeding, and exclusive breastfeeding. This review summarizes recent studies and new international development on the prevention of mother-to-child HIV transmission. Prevention of mother-to-child transmission of HIV should now be integrated as part of basic maternal and child health services.

Antiretroviral adherence and development of drug resistance are the strongest predictors of genital HIV-1 shedding among women initiating treatment

Persistent genital human immunodeficiency virus type 1 (HIV-1) shedding among women receiving antiretroviral therapy (ART) may present a transmission risk. We investigated the associations between genital HIV-1 suppression after ART initiation and adherence, resistance, pretreatment CD4 cell count, and hormonal contraceptive use. First-line ART was initiated in 102 women. Plasma and genital HIV-1 RNA levels were measured at months 0, 3, and 6. Adherence was a strong and consistent predictor of genital HIV-1 suppression (P < .001), whereas genotypic resistance was associated with higher vaginal HIV-1 RNA level at month 6 (P = .04). These results emphasize the importance of adherence to optimize the potential benefits of ART for reducing HIV-1 transmission risk.

Minority variants of drug-resistant HIV

Minor drug-resistant variants exist in every patient infected with human immunodeficiency virus (HIV). Because these minority variants are usually present at very low levels, they cannot be detected and quantified using conventional genotypic and phenotypic tests. Recently, several assays have been developed to characterize these low-abundance drug-resistant variants in the large, genetically complex population that is present in every HIV-infected individual. The most important issue is what results generated by these assays can predict clinical or treatment outcomes and might guide the management of patients in clinical practice. Cutoff values for the detection of these low-abundance viral variants that predict an increased risk of treatment failure should be determined. These thresholds may be specific for each mutation and treatment regimen. In this review, we summarize the attributes and limitations of the currently available detection assays and review the existing information about both acquired and transmitted drug-resistant minority variants.

Resistance considerations in sequencing of antiretroviral therapy in low-middle income countries with currently available options

PURPOSE OF REVIEW

Access to antiretroviral therapy (ART) has been scaled-up in low-middle income countries (LMICs), where the majority of the world's HIV-1-infected population is living. Concerns towards the emergence and spread of HIV-1 drug resistance exist, given the lack of virological monitoring which may give rise to accumulation of resistance as well as the use of suboptimal ART in pregnant women with the aim to reduce perinatal transmission. Knowledge of the prevalence of transmitted and emerging drug resistance as well as its specific patterns is of help in guiding the selection of appropriate ART types and sequencing strategies.

RECENT FINDINGS

Whereas transmitted drug resistance in LMIC is still limited, resistance in pregnant women as a consequence of suboptimal ART for the prevention of vertical transmission is frequent and dependent on viral subtype and load. Accumulation of drug resistance during first-line ART depends on the frequency of monitoring, whereas mutational patterns are influenced by type of ART and, partly, viral subtype.

SUMMARY

Optimized ART for prevention of mother-to-child transmission and closer monitoring of ART programs with the inclusion of viral load may help reducing unnecessary development of HIV drug resistance in LMIC and preserve the limited available treatment options.

Use of antiretrovirals during pregnancy and breastfeeding in low-income and middle-income countries

PURPOSE OF REVIEW

The purpose of the study was to review recent evidence on the use of antiretrovirals during pregnancy and breastfeeding in low-income and middle-income settings.

RECENT FINDINGS

Access to antiretroviral prophylaxis strategies for HIV-infected pregnant women has increased globally, but two-thirds of women in need still do not receive even the simplest regimen for the prevention of mother-to-child transmission of HIV, and most pregnant women in need of antiretroviral treatment do not receive it. The use of combination antiretroviral treatment in pregnancy in low-resource settings is safe and effective, and increasing evidence supports starting ongoing antiretroviral treatment at a CD4 cell count below 350/microl in pregnant women. The use of appropriate short-course antiretroviral prophylactic regimens is effective for prevention of mother-to-child transmission of HIV in women with higher CD4 cell counts. New data on the use of antiretroviral prophylaxis to prevent transmission through breastfeeding demonstrate that both maternal antiretroviral treatment and extended infant prophylaxis are effective.

SUMMARY

Antiretroviral use in pregnancy can benefit mothers in need of treatment and reduce the risk of mother-to-child transmission. Emerging evidence of the effectiveness of antiretroviral prophylaxis in preventing transmission through breastfeeding is encouraging and likely to influence practice in the future.

Antiretroviral strategies to prevent mother-to-child transmission of HIV: striking a balance between efficacy, feasibility, and resistance

Dara Lehman and colleagues discuss a randomized trial that found that adding up to a week of twice-daily zidovudine+lamivudine to single-dose nevirapine reduces the risk of resistance in mothers and infants.