HIV-1 Drug Resistance by Ultra-Deep Sequencing Following Short Course Zidovudine, Single-Dose Nevirapine, and Single-Dose Tenofovir with Emtricitabine for Prevention of Mother-to-Child Transmission

HIV Drug Resistance in Children and Adolescents: Always a Challenge?

Purpose of Review

With the expanded roll-out of antiretrovirals for treatment and prevention of HIV during the last decade, the emergence of HIV drug resistance (HIVDR) has become a growing challenge. This review provides an overview of the epidemiology and trajectory of HIVDR globally with an emphasis on pediatric and adolescent populations.

Recent Findings

HIVDR is associated with suboptimal virologic suppression and treatment failure, leading to an increased risk of HIV transmission to uninfected people and increased morbidity and mortality among people living with HIV. High rates of HIVDR to non-nucleoside reverse transcriptase inhibitors globally are expected to decline with the introduction of the integrase strand transfer inhibitors and long-acting combination regimens, while challenge remains for HIVDR to other classes of antiretroviral drugs.

Summary

We highlight several solutions including increased HIV viral load monitoring, expanded HIVDR surveillance, and adopting antiretroviral regimens with a high-resistance barrier to decrease HIVDR. Implementation studies and programmatic changes are needed to determine the best approach to prevent and combat the development of HIVDR.

Drug resistance patterns in HIV patients with virologic failure in Iran

We reviewed the medical charts of 1,700 patients diagnosed with HIV who referred to a central HIV clinic in Tehran between 2004 and 2017. Participants who had a viral load of > 200 copies/mL after six months or more on antiretroviral therapy (ART) were grouped as virologic failure (VF). We assessed the demographic characteristics, diagnosis date, first ART regimen, and resistance to various ART drugs. Out of 1,700 patients, 72 (4.2%) had a treatment failure. Among those with treatment failure, 51.3% were on zidovudine + lamivudine + efavirenz, 13.9% were on tenofovir + lamivudine + lopinavir/ritonavir, and 12.5% were on tenofovir + emtricitabine + efavirenz. In patients with treatment failure, the highest resistance was to nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs) combination (44.4%). In these patients, resistance to tenofovir (one of the NRTIs) was 29.1%. The highest treatment failure was observed among patients treated with nevirapine (NVP) and efavirenz (EFV)-based regimen. Our findings suggest that protease inhibitors should be considered as first-line drugs in ART regimens in VF patients in Iran.

Drug resistance from preferred antiretroviral regimens for HIV infection in South Africa: A modeling study

BACKGROUND

Tenofovir-containing regimens comprise the preferred first-line antiretroviral therapy (ART) in many countries including South Africa, where utilization of second-line regimens is limited. Considerable HIV drug resistance has occurred among persons failing tenofovir-containing first-line ART. We evaluated drug resistance at the population level using mathematical modeling.

SETTING

Heterosexual HIV epidemic in KwaZulu-Natal, South Africa.

METHODS

We constructed a stochastic individual-based model and simulated scenarios of ART implementation, either CD4-based (threshold < 500 cells/mL) or Fast-track (81% coverage by 2020), with consideration of major drug-associated mutations (M184V, K65R and non-nucleoside reverse transcriptase inhibitor (NNRTI)). Using base case and uncertainty analyses, we assessed (majority) drug resistance levels.

RESULTS

By 2030, the median total resistance (proportion of HIV-infected persons with drug resistance) is predicted to reach 31.4% (interquartile range (IQR): 16.5%-50.2%) with CD4-based ART, decreasing to 14.5% (IQR: 7.7%-25.8%) with Fast-track implementation. In both scenarios, we find comparably high prevalence (~80%) of acquired NNRTI-associated, M184V and K65R mutations. Over 48% of individuals with acquired resistance harbor dual, 44% triple and 7% just single drug mutations. Drug-resistant HIV is predicted to comprise 40% (IQR: 27%-50%) of incident infections, while 70% of prevalent transmitted resistance is NNRTI-associated. At 2018, the projected total resistance is 15% (IQR: 7.5%-25%), with 18% (IQR: 13%-24%) of incident infections from transmitted drug-resistant HIV.

CONCLUSIONS

WHO-recommended preferred first-line ART could lead to substantial drug resistance. Effective surveillance of HIV drug resistance and utilization of second-line as well as alternative first-line regimens is crucial.

What is new in perinatal HIV prevention?

PURPOSE OF REVIEW

The purpose of this review is to describe recent clinical trial, laboratory and observational findings that highlight both the progress that can be achieved in elimination of new pediatric infections in international clinical trial settings among HIV-infected breastfeeding women while also describing recent safety concerns related to currently used antiretroviral regimens. The article will also address the ongoing adherence challenges for HIV-infected mothers in taking their antiretroviral drugs. This information is timely and relevant as new regimens are being considered for both prevention of mother-to-child transmission (PMTCT) of HIV and HIV treatment options worldwide.

RECENT FINDINGS

The main themes described in this article include both efficacy of different antiretroviral therapy (ART) regimens currently being rolled out internationally for PMTCT as well as safety findings from recent research including a large multisite international trial, PROMISE.

SUMMARY

The findings from the IMPAACT PROMISE trial as well as other recent trial and observational findings suggest that while progress has been steady in reducing PMTCT worldwide, the goal of virtual elimination of pediatric HIV worldwide will require careful attention to optimizing safety of new regimens which are less dependent on maternal daily ART adherence and safer in preventing certain toxicities.