Slower clearance of nevirapine resistant virus in infants failing extended nevirapine prophylaxis for prevention of mother-to-child HIV transmission

Resistance Mutation Patterns among HIV-1-Infected Children and Features of the Program for Prevention of Mother-to-Child Transmission in Vietnam's Central Highlands and Southern Regions, 2017-2021

The Vietnam Ministry of Health (MOH) has intensified efforts in its aim to eliminate AIDS by 2030. Expanding the program for prevention of mother-to-child transmission (PMTCT) is a significant step towards achieving this goal. However, there are still HIV-exposed children who do not have access to PMTCT services, and some who have participated in the program but still contracted HIV. This study focused on assessing the prevalence and profile of HIV mutations among children under 18 months of age who had recently tested positive for HIV, while gaining insights into the implementation of early infant diagnostic (EID) tests. Between 2017 and 2021, 3.43% of 5854 collected dry blood spot (DBS) specimens from Vietnam's Central and Southern regions showed positive EID results. This study identified a high prevalence of resistance mutations in children, totaling 62.9% (95% CI: 53.5-72.3). The highest prevalence of mutations was observed for NNRTIs, with 57.1% (95% CI: 47.5-66.8). Common mutations included Y181C and K103N (NNRTI resistance), M184I/V (NRTI resistance), and no major mutations for PI. The percentage of children with any resistance mutation was significantly higher among those who received PMTCT interventions (69.2%; 95% CI: 50.5-92.6%) compared with those without PMTCT (45.0%; 95% CI: 26.7-71.1%) with χ2 = 6.06, p = 0.0138, and OR = 2.75 (95% CI: 1.13-6.74). Mutation profiles revealed that polymorphic mutations could be present regardless of whether PMTCT interventions were implemented or not. However, non-polymorphic drug resistance mutations were predominantly observed in children who received PMTCT measures. Regarding PMTCT program characteristics, this study highlights the issue of late access to HIV testing for both mothers and their infected children. Statistical differences were observed between PMTCT and non-PMTCT children. The proportion of late detection of HIV infection and breastfeeding rates were significantly higher among non-PMTCT children (p < 0.05). Comparative analysis between children with low viral load (≤200 copies/mL) and high viral load (>200 copies/mL) showed significant differences between the mothers' current ART regimens (p = 0.029) and the ARV prophylaxis regimen for children (p = 0.016). These findings emphasize the need for comprehensive surveillance to assess the effectiveness of the PMTCT program, including potential transmission of HIV drug-resistance mutations from mothers to children in Vietnam.

Maternal HIV drug resistance is associated with vertical transmission and is prevalent in infected infants

BACKGROUND

We aimed to assess if maternal HIV drug resistance is associated with an increased risk of HIV vertical transmission and to describe the dynamics of drug resistance in HIV-infected infants.

METHODS

A case-control study of PROMISE study participants. "Cases" were mother-infant pairs with HIV vertical transmission during pregnancy or breastfeeding and "controls" were mother-infant pairs without transmission matched 1:3 by delivery date and clinical site. Genotypic HIV drug resistance analyses were performed on mothers' and their infants' plasma at or near the time of infant HIV diagnosis. Longitudinal analysis of genotypic resistance was assessed in available specimens from infants, from diagnosis and beyond, including ART initiation and last study visits.

RESULTS

Our analyses included 85 cases and 255 matched controls. Maternal HIV drug resistance, adjusted for plasma HIV RNA load at infant HIV diagnosis, enrollment CD4 count, and antepartum regimens, was not associated with in utero/peripartum HIV transmission. In contrast, both maternal plasma HIV RNA load and HIV drug resistance were independent risk factors associated with vertical transmission during breastfeeding. Furthermore, HIV drug resistance was selected across infected infants during infancy.

CONCLUSIONS

Maternal HIV drug resistance and maternal viral load were independent risk factors for vertical transmission during breastfeeding, suggesting that nevirapine alone may be insufficient infant prophylaxis against drug-resistant variants in maternal breast milk. These findings support efforts to achieve suppression of HIV replication during pregnancy and suggest that breastfeeding infants may benefit from prophylaxis with a greater barrier to drug resistance than nevirapine alone.

Human Immunodeficiency Virus Antiretroviral Resistance and Transmission in Mother-Infant Pairs Enrolled in a Large Perinatal Study

Background

The presence of antiretroviral drug-associated resistance mutations (DRMs) may be particularly problematic in human immunodeficiency virus (HIV)-infected pregnant women as it can lead to mother-to-child transmission (MTCT) of resistant HIV strains. This study evaluated the prevalence and the effect of antiretroviral DRMs in previously untreated mother-infant pairs.

Methods

A case-control design of 1:4 (1 transmitter to 4 nontransmitters) was utilized to evaluate DRMs as a predictor of HIV MTCT in specimens obtained from mother-infant pairs. ViroSeq HIV-1 genotyping was performed on mother-infant specimens to assess for clinically relevant DRMs.

Results

One hundred forty infants acquired HIV infection; of these, 123 mother-infant pairs (88%) had specimens successfully amplified using ViroSeq and assessed for drug resistance genotyping. Additionally, 483 of 560 (86%) women who did not transmit HIV to infants also had samples evaluated for DRMs. Sixty-three of 606 (10%) women had clinically relevant DRMs; 12 (2%) had DRMs against >1 drug class. Among 123 HIV-infected infants, 13 (11%) had clinically relevant DRMs, with 3 (2%) harboring DRMs against >1 drug class. In univariate and multivariate analyses, DRMs in mothers were not associated with increased HIV MTCT (adjusted odds ratio, 0.8 [95% confidence interval, .4-1.5]). Presence of DRMs in transmitting mothers was strongly associated with DRM presence in their infants (P < .001).

Conclusions

Preexisting DRMs were common in untreated HIV-infected pregnant women, but did not increase the risk of HIV MTCT. However, if women with DRMs are not virologically suppressed, they may transmit resistant mutations, thus complicating infant management.

Switching to Efavirenz Versus Remaining on Ritonavir-boosted Lopinavir in Human Immunodeficiency Virus-infected Children Exposed to Nevirapine: Long-term Outcomes of a Randomized Trial

Background

We previously demonstrated the noninferiority of switching to efavirenz (EFV) versus remaining on ritonavir-boosted lopinavir (LPV/r) for virologic control in children infected with human immunodeficiency virus (HIV) and exposed to nevirapine (NVP) for prevention of mother-to-child transmission. Here we assess outcomes up to 4 years post-randomization.

Methods

From 2010-2013, 298 NVP-exposed HIV-infected children ≥3 years of age were randomized to switch to EFV or remain on LPV/r in Johannesburg, South Africa (Clinicaltrials.gov NCT01146873). After trial completion, participants were invited to enroll into observational follow-up. We compared HIV RNA levels, CD4 counts and percentages, lipids, and growth across groups through four years post-randomization.

Results

HIV RNA levels 51-1000 copies/mL were less frequently observed in the EFV group than the LPV/r group (odds ratio [OR] 0.67, 95% confidence interval [CI]: 0.51-0.88, P = .004), as was HIV RNA >1000 copies/mL (OR 0.52 95% CI: 0.28-0.98, P = .04). The probability of confirmed HIV RNA >1000 copies/mL by 48 months was 0.07 and 0.12 in the EFV and LPV/r groups, respectively (P = .21). Children randomized to EFV had a reduced risk of elevated total cholesterol (OR 0.45 95% CI: 0.27-0.75, P = .002) and a reduced risk of abnormal triglycerides (OR 0.42, 95% CI 0.29-0.62, P < .001).

Conclusions

Our results indicate that the benefits of switching virologically suppressed NVP-exposed HIV-infected children ≥3 years of age from LPV/r to EFV are sustained long-term. This approach has several advantages, including improved palatability, reduced metabolic toxicity, simplified cotreatment for tuberculosis, and preservation of second line options.

Clinical Trials Registration

NCT01146873.

Treatment Outcomes and Resistance Patterns of Children and Adolescents on Second-Line Antiretroviral Therapy in Asia

BACKGROUND

Data on pediatric treatment outcomes and drug resistance while on second-line antiretroviral therapy (ART) are needed to guide HIV care in resource-limited countries.

METHODS

HIV-infected children <18 years who were switched or switching to second-line ART after first-line failure were enrolled from 8 sites in Indonesia, Thailand, and Vietnam. Genotyping was performed at virologic failure (VF; HIV-RNA >1000 copies/mL). Cox proportional hazards regression was used to evaluate factors predicting VF.

RESULTS

Of 277 children, 41% were female. At second-line switch, age was 7.5 (5.3-10.3) years, CD4 count was 300 (146-562) cells per cubic millimeter, and percentage was 13 (7-20%); HIV-RNA was 5.0 (4.4-5.5) log10 copies per milliliter. Second-line regimens contained lamivudine (90%), tenofovir (43%), zidovudine or abacavir (30%), lopinavir (LPV/r; 91%), and atazanavir (ATV; 7%). After 3.3 (1.8-5.3) years on second-line ART, CD4 was 763 (556-1060) cells per cubic millimeter and 26% (20-31%). VF occurred in 73 (27%), with an incidence of 7.25 per 100 person-years (95% confidence interval [CI]: 5.77 to 9.12). Resistance mutations in 50 of 73 children with available genotyping at first VF included M184V (56%), ≥1 thymidine analogue mutation (TAM; 40%), ≥4 TAMs (10%), Q151M (4%), any major LPV mutation (8%), ≥6 LPV mutations (2%), and any major ATV mutation (4%). Associations with VF included age >11 years (hazard ratio [HR] 4.06; 95% CI: 2.15 to 7.66) and HIV-RNA >5.0 log10 copies per milliliter (HR 2.42; 95% CI: 1.27 to 4.59) at switch and were seen more commonly in children from Vietnam (HR 2.79; 95% CI: 1.55 to 5.02).

CONCLUSIONS

One-fourth of children developed VF while on second-line ART. However, few developed major mutations to protease inhibitors.

Persistence of HIV drug resistance among South African children given nevirapine to prevent mother-to-child-transmission

OBJECTIVES

We set out to examine the prevalence and persistence of mutations conferring high-level nonnucleoside reverse transcriptase (NNRTI)-resistance in a cohort of HIV-infected children who had failed prophylaxis to prevent mother-to-child-transmission (PMTCT).

DESIGN

A prospective observational cohort study at the Pediatric HIV Clinic at Kalafong Provincial Tertiary Hospital in Pretoria, South Africa.

METHODS

Children referred for initiation of antiretroviral therapy (ART) were enrolled from July 2010 through February 2013. HIV drug resistance testing was performed using the oligonucleotide ligation assay (OLA) on dried blood spots (DBS) collected at enrolment and monthly follow-up visits for 2 years.

RESULTS

South African children who failed HIV-prophylaxis had a high prevalence of NNRTI-resistant HIV (46/88; 52%). Among children with NNRTI-resistance, the frequency of the predominant resistant variant in each child's HIV-quasispecies was high (median 96%) at study entry (median age 7.5 months), and in 26 out of 27 followed a median of 13 months persisted at a high frequency (median 89%).

CONCLUSION

Our finding that infants who fail HIV-prophylaxis frequently have long-lived NNRTI-resistant HIV suggests that resistance will likely persist through 36 months of age, when children qualify for NNRTI-based ART. These children may benefit from HIV drug resistance testing to guide selection of their treatment.

Development of a Qualitative Quantitative Polymerase Chain Reaction Test to Identify Patients Failing First-Line Therapy to Non-Nucleotide Reverse Transcriptase Inhibitor

Antiretroviral therapy (ART) can be compromised by selection of drug resistance strains, which can be promoted by lack of adherence during therapy and drug tolerance, and some of these drug-resistant strains can persist for years as minority populations. The K103N drug resistance mutation is selected by the use of non-nucleotide reverse transcriptase inhibitors, including nevirapine or efavirenz (EFV), used in low-income countries. Here we describe the use of a less expensive qualitative point mutation polymerase chain reaction (PMqPCR_K103N) targeting K103N mutation. To validate the use of this methodology, we tested previously sequenced samples from patients treated with highly active ART with viral loads above 2,000 copies/ml and compared the results of our assay with Illumina deep sequencing. Due to its low cost and high specificity, this test is particularly suitable for low-income countries to screen for pretreatment resistance in patients either initiating ART or failing first-line regimens containing EFV.

Efficacy of Six-Week Extended-Dose Nevirapine Varies by Infant Birth Weight with Greatest Relative Efficacy in Low Birth Weight Infants

Latest World Health Organization guidelines recommend weight-based nevirapine prophylaxis for all HIV-exposed infants in resource-limited settings, yet low birth weight (LBW) infants (< 2500 g) have been understudied. Using data from the NIH-funded India six-week extended-dose nevirapine (SWEN) study, a randomized clinical trial of SWEN versus single-dose nevirapine (SD) for prevention of breast-milk HIV-1 transmission, we examined the relative impact of SWEN among 737 mother-infant pairs stratified by infant birth weight. Birth weight groups were defined as very LBW (VLBW) ≤ 2000 g, moderate LBW (MLBW) >2000 g and ≤ 2500 g, and normal birth weight (NBW) > 2500 g. Outcomes were HIV-1 infection, HIV-1 infection or death by 12 months, and severe adverse events (SAEs). The Kaplan-Meier method was used to estimate probability of efficacy outcomes in birth weight groups, and differential effects of SWEN by birth weight group were examined using Cox proportional hazards models adjusting for independent risk factors for HIV maternal-to-child transmission and significant covariates. Among 50 VLBW, 249 MLBW, and 433 NBW infants, 50% were randomized to SWEN; median gestational age was 36, 38 and 38 weeks, respectively; and there was no difference in breastfeeding duration (p = 0.99). Compared to SD: SWEN-treated VLBW had lower estimates of HIV-1 infection (13% vs. 38%, p = 0.004) and HIV-1 infection or death (13% vs. 41%, p = 0.002); SWEN-treated MLBW had lower estimated HIV-1 infection (13% vs. 17%, p = 0.042); and efficacy endpoints were similar by treatment arm in NBW. In multivariate analysis, SWEN was associated with reduced risk of HIV-1 infection or death by 83% (p = 0.03) in VLBW versus 45% (p = 0.05) in MLBW. SAE frequency was similar by treatment arm in VLBW (68% vs. 76%, p = 0.53) and MLBW (37% vs. 36%, p = 0.93). SWEN may safely increase HIV-free survival among HIV-exposed LBW infants with greatest protective advantage among infants ≤ 2000 g.

Early short-term treatment with neutralizing human monoclonal antibodies halts SHIV infection in infant macaques

Prevention of mother to child transmission (MTCT) of HIV remains a major objective where antenatal care is not readily accessible. We tested anti-HIV-1 human neutralizing monoclonal antibodies (NmAb) as post-exposure therapy in an infant macaque model for intrapartum MTCT. One-month-old rhesus macaques were inoculated orally with SHIV_SF162P3. On days 1, 4, 7, and 10 after virus exposure, we injected animals subcutaneously with NmAbs and quantified systemic distribution of NmAbs in multiple tissues within 24 h following administration. Replicating virus was found in multiple tissues by day 1 in animals without treatment. All NmAb-treated macaques were free of virus in blood and tissues at 6 months post-exposure. We detected no anti-SHIV T cell responses in blood or tissues at necropsy, and no virus emerged following CD8⁺ T cell depletion. These results suggest early passive immunotherapy can eliminate early viral foci and thereby prevent the establishment of viral reservoirs.

Genetic Analyses of HIV-1 Strains Transmitted from Mother to Child in Northern Vietnam

We previously reported mother-to-child transmission of HIV-1 in nine (6.7%) of 135 children on nevirapine prophylaxis in Vietnam. In the current study, we investigated the appearance and profile of antiretroviral drug (ARV) resistance mutations, the predicted coreceptor usage, and the genetic diversity of HIV-1 strains isolated from the eight pairs of HIV-1-infected mothers and their children, who were followed up to 12 months after birth. Portions of the pol and env C2V3 regions of the HIV-1 strains were analyzed genetically. HIV-1 CRF01_AE RNA was detected in four (50%) children at delivery. Y181C, a nevirapine resistance mutation, appeared in two (25%) children 1 and 3 months after birth, respectively. No ARV resistance mutation was detected in the mothers, though three mothers were on ARV prophylaxis. Five mothers and their children harbored CCR5-tropic (R5) viruses. Two mothers harbored both R5 and CXCR4-tropic (X4) viruses, but their children harbored only R5 viruses even though the X4 viruses were dominant in the mothers. In the remaining one mother, HIV-1 RNA was not amplified and her child harbored both R5 and X4 viruses at birth, but only X4 virus 12 months after delivery. The infants' viruses were more homogeneous than their mothers' viruses (mean distance: 0.5% vs. 1.1%, respectively). This is the first molecular epidemiological study of vertical HIV-1 infections in Vietnam. These findings may provide useful knowledge for the prevention of mother-to-child transmission of HIV-1 and the antiretroviral treatment of children in Vietnam.

Improving early infant HIV diagnosis in Kenya: study protocol of a cluster-randomized efficacy trial of the HITSystem

Background

Early infant diagnosis among human immunodeficiency virus (HIV)-exposed infants is a critical component of prevention of mother-to-child transmission programs. Barriers to early infant diagnosis include poor uptake, low retention at designated re-testing intervals, delayed test results, passive systems of communication, and poor linkage to treatment. This study will evaluate the HIV Infant Tracking System (HITSystem), an eHealth intervention that streamlines communication and accountability between the key early infant diagnosis stakeholders: HIV+ mothers and their HIV-exposed infants, healthcare providers, and central laboratory personnel. It is hypothesized that the HITSystem will significantly improve early infant diagnosis retention at 9 and 18 months postnatal and the timely provision of services.

Methods/design

Using a phased cluster-randomized controlled trial design, we will evaluate the impact of the HITSystem on eight primary benchmarks in the 18-month long cascade of care for early infant diagnosis. Study sites are six government hospitals in Kenya matched on geographic region, resource level, and patient volume. Early infant diagnosis outcomes of mother-infant dyads (n = 120 per site) at intervention hospitals (n = 3) where the HITSystem is deployed at baseline will be compared to the matched control sites providing standard care. After allowing for sufficient time for enrollment and 18-month follow-up of dyads, the HITSystem will be deployed at the control sites in the end of Year 3. Primary outcomes are retention among mother-infant dyads, initiation of antiretroviral therapy among HIV-infected infants, and the proportion of services delivered within the optimal time window indicated by national and study guidelines. Satisfaction interviews with participants and providers will inform intervention improvements. Cost-effectiveness analyses will be conducted to inform the sustainability of the HITSystem. Hypothesized outcomes include significantly higher retention throughout the 18-month early infant diagnosis process, significantly more services provided on-time at intervention sites, and a potential savings to the healthcare system.

Discussion

This study will evaluate the public health impact of the HITSystem to improve critical early infant diagnosis outcomes in low-resource settings. Cost-effectiveness analyses will inform the feasibility of scale-up in other settings.

Trial registration

ClinicalTrials.gov: NCT02072603

Safety and effectiveness of combination antiretroviral therapy during the first year of treatment in HIV-1 infected Rwandan children: a prospective study

Background

With increased availability of paediatric combination antiretroviral therapy (cART) in resource limited settings, cART outcomes and factors associated with outcomes should be assessed.

Methods

HIV-infected children <15 years of age, initiating cART in Kigali, Rwanda, were followed for 18 months. Prospective clinical and laboratory assessments included weight-for-age (WAZ) and height-for-age (HAZ) z-scores, complete blood cell count, liver transaminases, creatinine and lipid profiles, CD4 T-cell count/percent, and plasma HIV-1 RNA concentration. Clinical success was defined as WAZ and WAZ >−2, immunological success as CD4 cells ≥500/mm³ and ≥25% for respectively children over 5 years and under 5 years, and virological success as a plasma HIV-1 RNA concentration <40 copies/mL.

Results

Between March 2008 and December 2009, 123 HIV-infected children were included. The median (interquartile (IQR) age at cART initiation was 7.4 (3.2, 11.5) years; 40% were <5 years and 54% were female. Mean (95% confidence interval (95%CI)) HAZ and WAZ at baseline were −2.01 (−2.23, −1.80) and −1.73 (−1.95, −1.50) respectively and rose to −1.75 (−1.98, −1.51) and −1.17 (−1.38, −0.96) after 12 months of cART. The median (IQR) CD4 T-cell values for children <5 and ≥5 years of age were 20% (13, 28) and 337 (236, 484) cells/mm³respectively, and increased to 36% (28, 41) and 620 (375, 880) cells/mm³. After 12 months of cART, 24% of children had a detectable viral load, including 16% with virological failure (HIV-RNA>1000 c/mL). Older age at cART initiation, poor adherence, and exposure to antiretrovirals around birth were associated with virological failure. A third (33%) of children had side effects (by self-report or clinical assessment), but only 9% experienced a severe side effect requiring a cART regimen change.

Conclusions

cART in Rwandan HIV-infected children was successful but success might be improved further by initiating cART as early as possible, optimizing adherence and optimizing management of side effects.

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.

If you text them, they will come: using the HIV infant tracking system to improve early infant diagnosis quality and retention in Kenya

OBJECTIVE

The objective of this study is to evaluate the impact of the HIV Infant Tracking System (HITSystem) for quality improvement of early infant diagnosis (EID) of HIV services.

DESIGN AND SETTING

This observational pilot study compared 12 months of historical preintervention EID outcomes at one urban and one peri-urban government hospital in Kenya to 12 months of intervention data to assess retention and time throughout the EID cascade of care.

PARTICIPANTS

Mother-infant pairs enrolled in EID at participating hospitals before (n = 320) and during (n = 523) the HITSystem pilot were eligible to participate.

INTERVENTION

The HITSystem utilizes Internet-based coordination of the multistep PCR cycle, automated alerts to trigger prompt action from providers and laboratory technicians, and text messaging to notify mothers when results are ready or additional action is needed.

MAIN OUTCOME MEASURES

The main outcome measures were retention throughout EID services, meeting time-sensitive targets and improving results turn-around time, and increasing early antiretroviral therapy (ART) initiation among HIV-infected infants.

RESULTS

The HITSystem was associated with an increase in the proportion of HIV-exposed infants retained in EID care at 9 months postnatal (45.1-93.0% urban; 43.2-94.1% peri-urban), a decrease in turn-around times between sample collection, PCR results and notification of mothers in both settings, and a significant increase in the proportion of HIV-infected infants started on antiretroviral therapy at each hospital(14 vs. 100% urban; 64 vs. 100% peri-urban).

CONCLUSION

The HITSystem maximizes the use of easily accessible technology to improve the quality and efficiency of EID services in resource-limited settings.

Antiretroviral drug regimens to prevent mother-to-child transmission of HIV: a review of scientific, program, and policy advances for sub-Saharan Africa

Considerable advances have been made in the effort to prevent mother-to-child HIV transmission (PMTCT) in sub-Saharan Africa. Clinical trials have demonstrated the efficacy of antiretroviral regimens to interrupt HIV transmission through the antenatal, intrapartum, and postnatal periods. Scientific discoveries have been rapidly translated into health policy, bolstered by substantial investment in health infrastructure capable of delivering increasingly complex services. A new scientific agenda is also emerging, one that is focused on the challenges of effective and sustainable program implementation. Finally, global campaigns to "virtually eliminate" pediatric HIV and dramatically reduce HIV-related maternal mortality have mobilized new resources and renewed political will. Each of these developments marks a major step in regional PMTCT efforts; their convergence signals a time of rapid progress in the field, characterized by an increased interdependency between clinical research, program implementation, and policy. In this review, we take stock of recent advances across each of these areas, highlighting the challenges--and opportunities--of improving health services for HIV-infected mothers and their children across the region.

What is needed to eliminate new pediatric HIV infections: the contribution of model-based analyses

PURPOSE OF REVIEW

Computer simulation models can identify key clinical, operational, and economic interventions that will be needed to achieve the elimination of new pediatric HIV infections. In this review, we summarize recent findings from model-based analyses of strategies for prevention of mother-to-child HIV transmission (MTCT).

RECENT FINDINGS

In order to achieve elimination of MTCT (eMTCT), model-based studies suggest that scale-up of services will be needed in several domains: uptake of services and retention in care (the PMTCT 'cascade'), interventions to prevent HIV infections in women and reduce unintended pregnancies (the 'four-pronged approach'), efforts to support medication adherence through long periods of pregnancy and breastfeeding, and strategies to make breastfeeding safer and/or shorter. Models also project the economic resources that will be needed to achieve these goals in the most efficient ways to allocate limited resources for eMTCT. Results suggest that currently recommended PMTCT regimens (WHO Option A, Option B, and Option B+) will be cost-effective in most settings.

SUMMARY

Model-based results can guide future implementation science, by highlighting areas in which additional data are needed to make informed decisions and by outlining critical interventions that will be necessary in order to eliminate new pediatric HIV infections.

Evolving uses of oral reverse transcriptase inhibitors in the HIV-1 epidemic: from treatment to prevention

The HIV epidemic continues unabated, with no highly effective vaccine and no cure. Each new infection has significant economic, social and human costs and prevention efforts are now as great a priority as global antiretroviral therapy (ART) scale up. Reverse transcriptase inhibitors, the first licensed class of ART, have been at the forefront of treatment and prevention of mother to child transmission over the past two decades. Now, their use in adult prevention is being extensively investigated. We describe two approaches: treatment as prevention (TasP) - the use of combination ART (2NRTI and 1NNRTI) following HIV diagnosis to limit transmission and pre-exposure prophylaxis (PrEP) –the use of single or dual oral agents prior to sexual exposure. Prevention of mother-to-child transmission using NRTI has been highly successful, though does not involve sustained use of NRTI to limit transmission. Despite theoretical and preliminary support for TasP and PrEP, data thus far indicate that adherence, retention in care and late diagnosis are the major barriers to their successful, sustained implementation. Future advances in drug technologies will be needed to overcome the issue of drug adherence, through development of drugs that involve both less frequent dosing as well as reduced toxicity, possibly through specific targeting of infected cells.

Impact of maternal and infant antiretroviral drug regimens on drug resistance in HIV-infected breastfeeding infants

BACKGROUND

The HIV Prevention Trials Network (HPTN) 046 trial evaluated the efficacy of extended infant nevirapine (NVP) administration for prevention of HIV transmission through breastfeeding. Infants received daily NVP up to 6 weeks of age. HIV-uninfected infants (the intent-to-treat group) received daily NVP or placebo up to 6 months of age. We analyzed emergence of NVP resistance in infants who acquired HIV infection despite prophylaxis.

METHODS

HIV genotyping was performed using the ViroSeq HIV Genotyping System. Medians and proportions were used to summarize data. Two-sided Fisher exact tests were used to evaluate associations between categorical variables.

RESULTS

NVP resistance was detected in 12 (92.3%) of 13 infants who were HIV-infected by 6 weeks and in 7 (28%) of 25 infants who were HIV-uninfected at 6 weeks and HIV-infected at 6 months of age (6/8 = 75% in the NVP arm, 1/17 = 5.9% in the placebo arm, P = 0.001). Among those 25 infants, 4 had mothers who initiated an antiretroviral treatment regimen by 6 months postpartum. In all 4 cases, the treatment regimen included a non-nucleoside reverse transcriptase inhibitor (NVP or efavirenz). NVP resistance was detected in all 4 of those infants by 6 months of age (4/4 = 100%). In contrast, only 3 (14.2%) of the remaining 21 HIV-infected infants whose mothers did not initiate antiretroviral treatment developed NVP resistance (P = 0.003).

CONCLUSIONS

Extended NVP prophylaxis significantly increased the risk of NVP resistance in infants who acquired HIV infection after 6 weeks of age. Treatment of maternal HIV infection was also associated with emergence of NVP resistance in HIV-infected, breastfed infants.

Cost-effectiveness of World Health Organization 2010 guidelines for prevention of mother-to-child HIV transmission in Zimbabwe

BACKGROUND

In 2010, the World Health Organization (WHO) released revised guidelines for prevention of mother-to-child human immunodeficiency virus (HIV) transmission (PMTCT). We projected clinical impacts, costs, and cost-effectiveness of WHO-recommended PMTCT strategies in Zimbabwe.

METHODS

We used Zimbabwean data in a validated computer model to simulate a cohort of pregnant, HIV-infected women (mean age, 24 years; mean CD4 count, 451 cells/µL; subsequent 18 months of breastfeeding). We simulated guideline-concordant care for 4 PMTCT regimens: single-dose nevirapine (sdNVP); WHO-recommended Option A, WHO-recommended Option B, and Option B+ (lifelong maternal 3-drug antiretroviral therapy regardless of CD4). Outcomes included maternal and infant life expectancy (LE) and lifetime healthcare costs (2008 US dollars [USD]). Incremental cost-effectiveness ratios (ICERs, in USD per year of life saved [YLS]) were calculated from combined (maternal + infant) discounted costs and LE.

RESULTS

Replacing sdNVP with Option A increased combined maternal and infant LE from 36.97 to 37.89 years and would reduce lifetime costs from $5760 to $5710 per mother-infant pair. Compared with Option A, Option B further improved LE (38.32 years), and saved money within 4 years after delivery ($5630 per mother-infant pair). Option B+ (LE, 39.04 years; lifetime cost, $6620 per mother-infant pair) improved maternal and infant health, with an ICER of $1370 per YLS compared with Option B.

CONCLUSIONS

Replacing sdNVP with Option A or Option B will improve maternal and infant outcomes and save money; Option B increases health benefits and decreases costs compared with Option A. Option B+ further improves maternal outcomes, with an ICER (compared with Option B) similar to many current HIV-related healthcare interventions.

Use of dried-blood-spot samples and in-house assays to identify antiretroviral drug resistance in HIV-infected children in resource-constrained settings

Monitoring HIV drug resistance is an important component of the World Health Organization's global HIV program. HIV drug resistance testing is optimal with commercially available clinically validated test kits using plasma; however, that type of testing may not be feasible or affordable in resource-constrained settings. HIV genotyping from dried blood spots (DBS) with noncommercial (in-house) assays may facilitate the capture of HIV drug resistance outcomes in resource-constrained settings but has had varying rates of success. With in-house assays for HIV reverse transcriptase, we evaluated the yield of genotyping DBS samples collected from HIV-infected children who were enrolled in two clinical trials conducted in sub-Saharan Africa (median HIV viral load, 5.88 log(10) HIV RNA copies/ml; range, 4.04 to 6.99). Overall, HIV genotypes were obtained for 94 (89.5%) of 105 samples tested (95% and 84% from clinical trials #1 and #2, respectively); however, successful analysis of 15 (16.1%) of the 94 samples required repeat testing using a different set of primers on previously synthesized cDNA. The yield of genotyping was lower on the DBS that were stored suboptimally from clinical trial #2 (56% versus 88% for optimally stored). Concordance with plasma genotypes derived using a clinically validated, commercial kit-based assay (ViroSeq HIV-1 genotyping system) was also assessed in a subset of children with paired testing. For 34 samples with paired DBS and plasma genotypes, there was 100% concordance for major drug resistance mutations. DBS genotyping using in-house assays provides an alternative for antiretroviral drug resistance testing in children in resource-constrained regions but may require region-specific optimization before widespread use.

Initiation of antiretroviral treatment in women after delivery can induce multiclass drug resistance in breastfeeding HIV-infected infants

BACKGROUND

The World Health Organization currently recommends initiation of highly active antiretroviral therapy (HAART) for human immunodeficiency virus (HIV)-infected lactating women with CD4+ cell counts <350 cells/μL or stage 3 or 4 disease. We analyzed antiretroviral drug resistance in HIV-infected infants in the Post Exposure Prophylaxis of Infants trial whose mothers initiated HAART postpartum (with a regimen of nevirapine [NVP], stavudine, and lamivudine). Infants in the trial received single-dose NVP and a week of zidovudine (ZDV) at birth; some infants also received extended daily NVP prophylaxis, with or without extended ZDV prophylaxis.

METHODS

We analyzed drug resistance in plasma samples collected from all HIV-infected infants whose mothers started HAART in the first postpartum year. Resistance testing was performed using the first plasma sample collected within 6 months after maternal HAART initiation. Categorical variables were compared by exact or trend tests; continuous variables were compared using rank-sum tests.

RESULTS

Multiclass resistance (MCR) was detected in HIV from 11 (29.7%) of 37 infants. Infants were more likely to develop MCR infection if their mothers initiated HAART earlier in the postpartum period (by 14 weeks vs after 14 weeks and up to 6 months vs after 6 months, P = .0009), or if the mother was exclusively breastfeeding at the time of HAART initiation (exclusive breastfeeding vs mixed feeding vs no breastfeeding, P = .003).

CONCLUSIONS

Postpartum maternal HAART initiation was associated with acquisition of MCR in HIV-infected breastfeeding infants. The risk was higher among infants whose mothers initiated HAART closer to the time of delivery or were still exclusively breastfeeding when they first reported HAART use.

Early infant HIV-1 diagnosis programs in resource-limited settings: opportunities for improved outcomes and more cost-effective interventions

Early infant diagnosis (EID) of HIV-1 infection confers substantial benefits to HIV-infected and HIV-uninfected infants, to their families, and to programs providing prevention of mother-to-child transmission (PMTCT) services, but has been challenging to implement in resource-limited settings. In order to correctly inform parents/caregivers of infant infection status and link HIV-infected infants to care and treatment, a 'cascade' of events must successfully occur. A frequently cited barrier to expansion of EID programs is the cost of the required laboratory assays. However, substantial implementation barriers, as well as personnel and infrastructure requirements, exist at each step in the cascade. In this update, we review challenges to uptake at each step in the EID cascade, highlighting that even with the highest reported levels of uptake, nearly half of HIV-infected infants may not complete the cascade successfully. We next synthesize the available literature about the costs and cost effectiveness of EID programs; identify areas for future research; and place these findings within the context of the benefits and challenges to EID implementation in resource-limited settings.

Analysis of nevirapine resistance in HIV-infected infants who received extended nevirapine or nevirapine/zidovudine prophylaxis

BACKGROUND

In the Post Exposure Prophylaxis of Infants (PEPI)-Malawi trial, infants received up to 14 weeks of extended nevirapine (NVP) or extended NVP with zidovudine (NVP + ZDV) to prevent postnatal HIV transmission. We examined emergence and persistence of NVP resistance in HIV-infected infants who received these regimens prior to HIV diagnosis.

METHODS

Infant plasma samples collected at 14 weeks of age were tested using the ViroSeq HIV Genotyping System and a sensitive point mutation assay, LigAmp (for K103N and Y181C). Samples collected at 6 and 12 months of age were analyzed using LigAmp.

RESULTS

At 14 weeks of age, NVP resistance was detected in samples from 82 (75.9%) of 108 HIV-infected infants. Although the frequency of NVP resistance detected by ViroSeq was lower in the extended NVP + ZDV arm than in the extended NVP arm, the difference was not statistically significant (38/55 = 69.1% vs. 44/53 = 83.0%, P = 0.12). Similar results were obtained using LigAmp. Using LigAmp, the proportion of infants who still had detectable NVP resistance at 6 and 12 months was similar among infants in the two study arms (at 6 months: 17/20 = 85.0% for extended NVP vs. 21/26 = 80.8% for extended NVP + ZDV, P = 1.00; at 12 months: 9/16 = 56.3% for extended NVP vs.10/13 = 76.9% for extended NVP + ZDV, P = 0.43).

CONCLUSION

Infants exposed to extended NVP or extended NVP + ZDV had high rates of NVP resistance at 14 weeks of age, and resistant variants frequently persisted for 6-12 months. Frequency and persistence of NVP resistance did not differ significantly among infants who received extended NVP only vs. extended NVP + ZDV prophylaxis.