Assessing the Paradox Between Transmitted and Acquired HIV Type 1 Drug Resistance Mutations in the Swiss HIV Cohort Study From 1998 to 2012

Self-reported neurocognitive complaints in the Swiss HIV Cohort Study: a viral genome-wide association study

People with HIV may report neurocognitive complaints, with or without associated neurocognitive impairment, varying between individuals and populations. While the HIV genome could play a major role, large systematic viral genome-wide screens to date are lacking. The Swiss HIV Cohort Study biannually enquires neurocognitive complaints. We quantified broad-sense heritability estimates using partial 'pol' sequences from the Swiss HIV Cohort Study resistance database and performed a viral near full-length genome-wide association study for the longitudinal area under the curve of neurocognitive complaints. We performed all analysis (i) restricted to HIV Subtype B and (ii) including all HIV subtypes. From 8547 people with HIV with neurocognitive complaints, we obtained 6966 partial 'pol' sequences and 2334 near full-length HIV sequences. Broad-sense heritability estimates for presence of memory loss complaints ranged between 1% and 17% (Subtype B restricted 1-22%) and increased with the stringency of the phylogenetic distance thresholds. The genome-wide association study revealed one amino acid (Env L641E), after adjusting for multiple testing, positively associated with memory loss complaints (P = 4.3 * 10-6). Other identified mutations, while insignificant after adjusting for multiple testing, were reported in other smaller studies (Tat T64N, Env *291S). We present the first HIV genome-wide association study analysis of neurocognitive complaints and report a first estimate for the heritability of neurocognitive complaints through HIV. Moreover, we could identify one mutation significantly associated with the presence of memory loss complaints. Our findings indicate that neurocognitive complaints are polygenetic and highlight advantages of a whole genome approach for pathogenicity determination.

Cohort Profile: The Zurich Primary HIV Infection Study

The Zurich Primary HIV Infection (ZPHI) study is a longitudinal cohort study established in 2002, aiming to study the clinical, epidemiological, and biological characteristics of primary HIV infection. The ZPHI enrolls individuals with documented primary HIV-1 infection. At the baseline and thereafter, the socio-demographic, clinical, and laboratory data are systematically collected, and regular blood sampling is performed for biobanking. By the end of December 2022, 486 people were enrolled, of which 353 were still undergoing active follow-up. Of the 486 participants, 86% had an acute infection, and 14% a recent HIV-1 infection. Men who have sex with men accounted for 74% of the study population. The median time from the estimated date of infection to diagnosis was 32 days. The median time from diagnosis to the initiation of antiretroviral therapy was 11 days, and this has consistently decreased over the last two decades. During the seroconversion phase, 447 (92%) patients reported having symptoms, of which only 73% of the patients were classified as having typical acute retroviral syndrome. The ZPHI study is a well-characterized cohort belonging to the most extensively studied primary HIV infection cohort. Its findings contribute to advancing our understanding of the early stages of HIV infection and pathogenesis, and it is paving the way to further improve HIV translational research and HIV medicine.

Web Service for HIV Drug Resistance Prediction Based on Analysis of Amino Acid Substitutions in Main Drug Targets

Predicting viral drug resistance is a significant medical concern. The importance of this problem stimulates the continuous development of experimental and new computational approaches. The use of computational approaches allows researchers to increase therapy effectiveness and reduce the time and expenses involved when the prescribed antiretroviral therapy is ineffective in the treatment of infection caused by the human immunodeficiency virus type 1 (HIV-1). We propose two machine learning methods and the appropriate models for predicting HIV drug resistance related to amino acid substitutions in HIV targets: (i) k-mers utilizing the random forest and the support vector machine algorithms of the scikit-learn library, and (ii) multi-n-grams using the Bayesian approach implemented in MultiPASSR software. Both multi-n-grams and k-mers were computed based on the amino acid sequences of HIV enzymes: reverse transcriptase and protease. The performance of the models was estimated by five-fold cross-validation. The resulting classification models have a relatively high reliability (minimum accuracy for the drugs is 0.82, maximum: 0.94) and were used to create a web application, HVR (HIV drug Resistance), for the prediction of HIV drug resistance to protease inhibitors and nucleoside and non-nucleoside reverse transcriptase inhibitors based on the analysis of the amino acid sequences of the appropriate HIV proteins from clinical samples.

Low rate of pre-exposure prophylaxis and post-exposure prophylaxis uptake and high prevalence of transmitted drug resistance among newly diagnosed primary HIV infections in Shenzhen, China: a real-world retrospective study

BACKGROUND

Understanding the characteristics of newly diagnosed primary human deficiency virus-1 (HIV-1) infection in the context of the post-antiretroviral therapy era and HIV drug prophylaxis is essential for achieving the new target of 95-95-95-95 by 2025. This study reported the characteristics of newly diagnosed primary HIV-1 infection in Shenzhen.

METHODS

This is a real-world retrospective study. Eighty-seven newly diagnosed primary HIV-1-infected patients were recruited from January 2021 to March 2022 at the Third People's Hospital of Shenzhen. Demographic, epidemiological, diagnostic, drug resistance, and medical data were described and analyzed.

RESULTS

Overall, 96.6% (84/87) of the newly identified primary HIV-1-infected patients were male, including 88.5% (77/87) men have sex with men (MSM), with a median age of 29.0 years (Q1-Q3: 24.0-34.0 years); of these, 85.1% (74/87) reported high-risk sexual behaviors with casual partners. The rate of condom usage was only 28.7% (25/87). The overall rate of pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) was 8.0% (7/87, including 4 PrEP and 3 PEP cases) around the potential exposure, although 41.4% of the patients had prior awareness of such interventions. Moreover, only 19.5% (17/87) had previously used PrEP or PEP. Of those, 58.8% (10/17) of the patients obtained drugs from the internet, and only 35.3% (6/17) reported good compliance. A total of 54.0% (47/87) of subjects were diagnosed by the HIV nucleic acid test. Acute retroviral syndrome appeared in 54.0% (47/87) of patients. The prevalence of transmitted drug resistance (TDR) mutation was 33.9% (19/56), including 6 (10.7%) against nucleoside reverse transcriptase inhibitor (NRTI) plus non-nucleoside reverse transcriptase inhibitor (NNRTI), 8 (14.3%) against NNRTI, and 5 (8.9%) against protease inhibitor (PI) only.

CONCLUSIONS

Owing to the low utilization rate and incorrect usage of PrEP and PEP, massive efforts are needed to promote HIV-preventive strategies in the MSM population. The extremely high prevalence of TDR mutation in this population implies the need for future pretreatment drug resistance surveillance.

A Systematic Molecular Epidemiology Screen Reveals Numerous Human Immunodeficiency Virus (HIV) Type 1 Superinfections in the Swiss HIV Cohort Study

BACKGROUND

Studying human immunodeficiency virus type 1 (HIV-1) superinfection is important to understand virus transmission, disease progression, and vaccine design. But detection remains challenging, with low sampling frequencies and insufficient longitudinal samples.

METHODS

Using the Swiss HIV Cohort Study (SHCS), we developed a molecular epidemiology screening for superinfections. A phylogeny built from 22 243 HIV-1 partial polymerase sequences was used to identify potential superinfections among 4575 SHCS participants with longitudinal sequences. A subset of potential superinfections was tested by near-full-length viral genome sequencing (NFVGS) of biobanked plasma samples.

RESULTS

Based on phylogenetic and distance criteria, 325 potential HIV-1 superinfections were identified and categorized by their likelihood of being detected as superinfections due to sample misidentification. NFVGS was performed for 128 potential superinfections; of these, 52 were confirmed by NFVGS, 15 were not confirmed, and for 61 sampling did not allow confirming or rejecting superinfection because the sequenced samples did not include the relevant time points causing the superinfection signal in the original screen. Thus, NFVGS could support 52 of 67 adequately sampled potential superinfections.

CONCLUSIONS

This cohort-based molecular approach identified, to our knowledge, the largest population of confirmed superinfections, showing that, while rare with a prevalence of 1%-7%, superinfections are not negligible events.

Prevalence and evolution of transmitted HIV drug resistance in Belgium between 2013 and 2019

Background

To assess the prevalence and evolution of transmitted drug resistance (TDR) in Belgium, a total of 3708 baseline human immunodeficiency virus (HIV)-1 polymerase sequences from patients diagnosed between 2013 and 2019 were analyzed.

Methods

Protease and reverse-transcriptase HIV-1 sequences were collected from the 7 national Aids Reference Laboratories. Subtype determination and drug resistance scoring were performed using the Stanford HIV Drug Resistance Database. Trends over time were assessed using linear regression, and the maximum likelihood approach was used for phylogenetic analysis.

Results

A total of 17.9% of the patients showed evidence of TDR resulting in at least low-level resistance to 1 drug (Stanford score  ≥15). If only the high-level mutations (Stanford score ≥60) were considered, TDR prevalence dropped to 6.3%. The majority of observed resistance mutations impacted the sensitivity for nonnucleoside reverse-transcriptase inhibitors (NNRTIs) (11.4%), followed by nucleoside reverse-transcriptase inhibitors (6.2%) and protease inhibitors (2.4%). Multiclass resistance was observed in 2.4%. Clustered onward transmission was evidenced for 257 of 635 patients (40.5%), spread over 25 phylogenetic clusters.

Conclusions

The TDR prevalence remained stable between 2013 and 2019 and is comparable to the prevalence in other Western European countries. The high frequency of NNRTI mutations requires special attention and follow-up. Phylogenetic analysis provided evidence for local clustered onward transmission of some frequently detected mutations.

Detecting Selection in the HIV-1 Genome during Sexual Transmission Events

Little is known about whether and how variation in the HIV-1 genome affects its transmissibility. Assessing which genomic features of HIV-1 are under positive or negative selection during transmission is challenging, because very few virus particles are typically transmitted, and random genetic drift can dilute genetic signals in the recipient virus population. We analyzed 30 transmitter–recipient pairs from the Zurich Primary HIV Infection Study and the Swiss HIV Cohort Study using near full-length HIV-1 genomes. We developed a new statistical test to detect selection during transmission, called Selection Test in Transmission (SeTesT), based on comparing the transmitter and recipient virus population and accounting for the transmission bottleneck. We performed extensive simulations and found that sensitivity of detecting selection during transmission is limited by the strong population bottleneck of few transmitted virions. When pooling individual test results across patients, we found two candidate HIV-1 genomic features for affecting transmission, namely amino acid positions 3 and 18 of Vpu, which were significant before but not after correction for multiple testing. In summary, SeTesT provides a general framework for detecting selection based on genomic sequencing data of transmitted viruses. Our study shows that a higher number of transmitter–recipient pairs is required to improve sensitivity of detecting selection.

Identifying and Characterizing Trans women in the Swiss HIV Cohort Study as an Epidemiologically Distinct Risk Group

BACKGROUND

As trans women are disproportionately affected by the HIV epidemic, and are still understudied, we aimed to identify and characterize the trans women in the Swiss HIV Cohort Study (SHCS).

METHODS

A combination of criteria from pre-existing cohort data was used to identify trans women. Information on socioeconomic factors, clinical data, risk behaviors, and mental health was collected. We also described their phylogenetic patterns within HIV transmission networks in relation to other risk groups.

RESULTS

We identified 89 trans women out of a total 20925 cohort participants. Trans women were much more likely to be Asian (30.3%) and Hispanic (15.7%) compared to men-who-have-sex with-men/MSM (2.5% and 4.1%, P value<0.001) and cis heterosexual (HET) women (7.0% and 3.3%, P value<0.001). Trans women were more similar to cis HET women in some measures like education level (post-secondary education attainment: 22.6% and 20.7% [P value =0.574], vs. 46.5% for MSM [P value<0.001]), while being more similar to MSM for measures like prior syphilis diagnosis (36.0% and 44.0% [P value=0.170], vs. 6.7% for cis HET women [P value <0.001]). 11.2% of trans women have been priorly hospitalized for psychological reasons, compared to 4.2% of MSM (P value=0.004) and 5.1% of cis HET women (P value=0.025). An analysis of transmission clusters containing trans women suggested greater affinity within the transmission networks to MSM compared to cis HET women.

CONCLUSIONS

Trans women are epidemiologically distinct in the setting of the Swiss HIV epidemic, warranting better identification and study to better serve this underserved risk group.

Increasing Frequency and Transmission of HIV-1 Non-B Subtypes among Men Who Have Sex with Men in the Swiss HIV Cohort Study

BACKGROUND

In Switzerland, HIV-1 transmission among men who have sex with men (MSM) has been dominated by subtype B, whilst non-B subtypes are commonly attributed to infections acquired abroad among heterosexuals. Here, we evaluated the temporal trends of non-B subtypes and the characteristics of molecular transmission clusters (MTCs) among MSM.

METHODS

Sociodemographic and clinical data and partial pol sequences were obtained from participants enrolled in the Swiss HIV Cohort Study (SHCS). For non-B subtypes, maximum likelihood trees were constructed, from which Swiss MTCs were identified and analysed by transmission group.

RESULTS

Non-B subtypes were identified in 8.1% (416/5,116) of MSM participants. CRF01_AE was the most prevalent strain (3.5%), followed by A (1.2%), F (1.1%), CRF02_AG (1.1%), C (0.9%), and G (0.3%). Between 1990 and 2019, an increase in the proportion of newly diagnosed individuals (0/123[0%] to 11/32 [34%]) with non-B subtypes in MSM was found. Across all non-B subtypes, the majority of MSM MTCs were European. Larger MTCs were observed for MSM than heterosexuals.

CONCLUSIONS

We found a substantial increase in HIV-1 non-B subtypes among MSM in Switzerland and the occurrence of large MTCs, highlighting the importance of molecular surveillance in guiding public health strategies targeting the HIV-1 epidemic.

Phylogenetic Cluster Analysis Identifies Virological and Behavioral Drivers of Human Immunodeficiency Virus Transmission in Men Who Have Sex With Men

BACKGROUND

Identifying local outbreaks and their drivers is a key step toward curbing human immunodeficiency virus (HIV) transmission and potentially achieving HIV elimination. Such outbreaks can be identified as transmission clusters extracted from phylogenetic trees constructed of densely sampled viral sequences. In this study, we combined phylogenetic transmission clusters with extensive data on virological suppression and behavioral risk of cluster members to quantify the drivers of ongoing transmission over 10 years.

METHODS

Using the comprehensive Swiss HIV Cohort Study and its drug-resistance database, we reconstructed phylogenetic trees for each year between 2007 and 2017. We identified HIV transmission clusters dominated by men who have sex with men (MSM) and determined their annual growth. We used Poisson regression to assess if cluster growth was associated with a per-cluster infectivity and behavioral risk score.

RESULTS

Both infectivity and behavioral risk scores were significantly higher in growing MSM transmission clusters compared to nongrowing clusters (P ≤ .01). The fraction of transmission clusters without infectious members acquiring new infections increased significantly over the study period. The infectivity score was significantly associated with per-capita incidence of MSM transmission clusters in 8 years, while the behavioral risk score was significantly associated with per-capita incidence of MSM transmission clusters in 3 years.

CONCLUSIONS

We present a phylogenetic method to identify hotspots of ongoing transmission among MSM. Our results demonstrate the effectiveness of treatment as prevention at the population level. However, the significantly increasing number of new infections among transmission clusters without infectious members highlights a relative shift from diagnosed to undiagnosed individuals as drivers of HIV transmission in Swiss MSM.

The Role of Human Immunodeficiency Virus (HIV) Asymptomatic Status When Starting Antiretroviral Therapy on Adherence and Treatment Outcomes and Implications for Test and Treat: The Swiss HIV Cohort Study

BACKGROUND

Since the advent of universal test-and-treat , more people living with human immunodeficiency virus (PLHIV) initiating antiretroviral therapy (ART) are asymptomatic with a preserved immune system. We explored the impact of asymptomatic status on adherence and clinical outcomes.

METHODS

PLHIV registered in the Swiss HIV Cohort Study (SHCS) between 2003 and 2018 were included. We defined asymptomatic as Centers for Disease Control and Prevention stage A within 30 days of starting ART, non-adherence as any self-reported missed doses and viral failure as two consecutive viral load>50 copies/mL after >24 weeks on ART. Using logistic regression models, we measured variables associated with asymptomatic status and adherence and Cox proportional hazard models to assess association between symptom status and viral failure.

RESULTS

Of 7131 PLHIV, 76% started ART when asymptomatic and 1478 (22%) experienced viral failure after a median of 1.9 years (interquartile range, 1.1-4.2). In multivariable models, asymptomatic PLHIV were more likely to be younger, men who have sex with men, better educated, have unprotected sex, have a HIV-positive partner, have a lower viral load, and have started ART more recently. Asymptomatic status was not associated with nonadherence (odds ratio, 1.03 [95% confidence interval {CI}, .93-1.15]). Asymptomatic PLHIV were at a decreased risk of viral failure (adjusted hazard ratio, 0.87 [95% CI, .76-1.00]) and less likely to develop resistance (14% vs 27%, P < .001) than symptomatic PLHIV.

CONCLUSIONS

Despite concerns regarding lack of readiness, our study found no evidence of adherence issues or worse clinical outcomes in asymptomatic PLHIV starting ART.

Emergence of Drug Resistance in the Swiss HIV Cohort Study Under Potent Antiretroviral Therapy Is Observed in Socially Disadvantaged Patients

BACKGROUND

The rate of acquired human immunodeficiency virus type 1 (HIV-1) drug resistance (ADR) has fallen dramatically since introduction of combined antiretroviral therapy (cART) in Switzerland. However, clinical experience indicates that there are still patients at risk of newly acquiring drug resistance despite having access to cART. Here, we characterized risk factors for ADR, to improve patient care and prevent emergence of drug resistance and treatment failure.

METHODS

We performed a case-control study to identify risk factors for ADR in all patients starting their first cART in the Swiss HIV Cohort Study (SHCS) since 1996. The SHCS is highly representative and includes >75% of patients receiving ART in Switzerland. To this end, we implemented a systematic medical chart review to obtain more detailed information on additional parameters, which are not routinely collected in the SHCS. The collected data were analyzed using univariable and multivariable conditional logistic regression.

RESULTS

We included in our study 115 cases and 115 matched controls. Unemployment (multivariable odds ratio [mOR], 2.9 [95% confidence interval {CI}, 1.3-6.4]; P = .008), African origin (mOR, 3.0 [95% CI, 1.0-9.2]; P = .047), comedication with anti-infectives (mOR, 3.7 [95% CI, 1.0-12.6]; P = .045), and symptoms of mental illness (mOR, 2.6 [95% CI, 1.2-5.5]; P = .012) were associated with ADR in the multivariable model.

CONCLUSIONS

Although ADR has become very rare with cART due to new potent therapies, patients in socially challenging life situations or presenting with mental health issues are at higher risk for drug resistance. Prompt identification and adequate support of these patients before ADR will prevent treatment failure and HIV-1 transmission.

Impact of scaling up dolutegravir on antiretroviral resistance in South Africa: A modeling study

BACKGROUND

Rising resistance of HIV-1 to non-nucleoside reverse transcriptase inhibitors (NNRTIs) threatens the success of the global scale-up of antiretroviral therapy (ART). The switch to WHO-recommended dolutegravir (DTG)-based regimens could reduce this threat due to DTG's high genetic barrier to resistance. We used mathematical modeling to predict the impact of the scale-up of DTG-based ART on NNRTI pretreatment drug resistance (PDR) in South Africa, 2020 to 2040.

METHODS AND FINDINGS

We adapted the Modeling Antiretroviral drug Resistance In South Africa (MARISA) model, an epidemiological model of the transmission of NNRTI resistance in South Africa. We modeled the introduction of DTG in 2020 under 2 scenarios: DTG as first-line regimen for ART initiators, or DTG for all patients, including patients on suppressive NNRTI-based ART. Given the safety concerns related to DTG during pregnancy, we assessed the impact of prescribing DTG to all men and in addition to (1) women beyond reproductive age; (2) women beyond reproductive age or using contraception; and (3) all women. The model projections show that, compared to the continuation of NNRTI-based ART, introducing DTG would lead to a reduction in NNRTI PDR in all scenarios if ART initiators are started on a DTG-based regimen, and those on NNRTI-based regimens are rapidly switched to DTG. NNRTI PDR would continue to increase if DTG-based ART was restricted to men. When given to all men and women, DTG-based ART could reduce the level of NNRTI PDR from 52.4% (without DTG) to 10.4% (with universal DTG) in 2040. If only men and women beyond reproductive age or on contraception are started on or switched to DTG-based ART, NNRTI PDR would reach 25.9% in 2040. Limitations include substantial uncertainty due to the long-term predictions and the current scarcity of knowledge about DTG efficacy in South Africa.

CONCLUSIONS

Our model shows the potential benefit of scaling up DTG-based regimens for halting the rise of NNRTI resistance. Starting or switching all men and women to DTG would lead to a sustained decline in resistance levels, whereas using DTG-based ART in all men, or in men and women beyond childbearing age, would only slow down the increase in levels of NNRTI PDR.

Martins MR, Vandamme AM, Camacho R, Gomes P, Abecasis A, on behalf of the Portuguese HIV-1 Resistance Study Group. Increasing Prevalence of HIV-1 Transmitted Drug Resistance in Portugal: Implications for First Line Treatment Recommendations

INTRODUCTION

Treatment for All recommendations have allowed access to antiretroviral (ARV) treatment for an increasing number of patients. This minimizes the transmission of infection but can potentiate the risk of transmitted (TDR) and acquired drug resistance (ADR).

OBJECTIVE

To study the trends of TDR and ADR in patients followed up in Portuguese hospitals between 2001 and 2017.

METHODS

In total, 11,911 patients of the Portuguese REGA database were included. TDR was defined as the presence of one or more surveillance drug resistance mutation according to the WHO surveillance list. Genotypic resistance to ARV was evaluated with Stanford HIVdb v7.0. Patterns of TDR, ADR and the prevalence of mutations over time were analyzed using logistic regression.

RESULTS AND DISCUSSION

The prevalence of TDR increased from 7.9% in 2003 to 13.1% in 2017 (p < 0.001). This was due to a significant increase in both resistance to nucleotide reverse transcriptase inhibitors (NRTIs) and non-nucleotide reverse transcriptase inhibitors (NNRTIs), from 5.6% to 6.7% (p = 0.002) and 2.9% to 8.9% (p < 0.001), respectively. TDR was associated with infection with subtype B, and with lower viral load levels (p < 0.05). The prevalence of ADR declined from 86.6% in 2001 to 51.0% in 2017 (p < 0.001), caused by decreasing drug resistance to all antiretroviral (ARV) classes (p < 0.001).

CONCLUSIONS

While ADR has been decreasing since 2001, TDR has been increasing, reaching a value of 13.1% by the end of 2017. It is urgently necessary to develop public health programs to monitor the levels and patterns of TDR in newly diagnosed patients.

Virological outcomes of boosted protease inhibitor-based first-line ART in subjects harbouring thymidine analogue-associated mutations as the sole form of transmitted drug resistance

Objectives

In subjects with transmitted thymidine analogue mutations (TAMs), boosted PIs (PI/b) are often chosen to overcome possible resistance to the NRTI backbone. However, data to guide treatment selection are limited. Our aim was to obtain firmer guidance for clinical practice using real-world cohort data.

Methods

We analysed 1710 subjects who started a PI/b in combination with tenofovir or abacavir plus emtricitabine or lamivudine, and compared their virological outcomes with those of 4889 patients who started an NNRTI (predominantly efavirenz), according to the presence of ≥1 TAM as the sole form of transmitted drug resistance.

Results

Participants with ≥1 TAM comprised predominantly MSM (213 of 269, 79.2%), subjects of white ethnicity (206 of 269, 76.6%) and HIV-1 subtype B infections (234 of 269, 87.0%). Most (203 of 269, 75.5%) had singleton TAMs, commonly a revertant of T215Y or T215F (112 of 269, 41.6%). Over a median of 2.5 years of follow-up, 834 of 6599 (12.6%) subjects experienced viraemia (HIV-1 RNA >50 copies/mL). The adjusted HR for viraemia was 2.17 with PI/b versus NNRTI-based therapy (95% CI 1.88–2.51; P < 0.001). Other independent predictors of viraemia included injecting drug use, black ethnicity, higher viral load and lower CD4 cell count at baseline, and receiving abacavir instead of tenofovir. Resistance showed no overall impact (adjusted HR 0.77 with ≥1 TAM versus no resistance; 95% CI 0.54–1.10; P = 0.15).

Conclusions

In this cohort, patients harbouring ≥1 TAM as the sole form of transmitted drug resistance gained no apparent virological advantage from starting first-line ART with a PI/b.

Characterization of subtypes and transmitted drug resistance strains of HIV among Beijing residents between 2001-2016

Background

Beijing is a national and international hub potentially containing a broad diversity of HIV variants. Previous studies on molecular epidemiology of HIV in Beijing pooled together samples from residents and non-residents. Pooling residents and non-residents has potentially introduced bias and undermined a good assessment and the intervention among the autochthonous population. Here, we aimed to define HIV subtype diversity and investigate the TDR in Beijing residents exclusively.

Methods

We analyzed the demographic, clinical, and virological data collected between 2001 and 2016 from residents in Beijing. A population-based sequencing of the HIV pol gene was carried out using plasma specimens. Phylogenetic analysis was performed in order to classify sequences into their corresponding subtypes using an automated subtyping tool, the Context-Based Modeling for Expeditious Typing (COMET). Furthermore, the drug resistance mutations were determined using the World Health Organization list for surveillance of TDR mutations.

Results

Data on TDR were available for 92% of 2,315 individuals with HIV infection, of whom 7.1% were women. The bioinformatic analysis of HIV strains from this study revealed that a combined 17 subtypes were circulating in Beijing, China between 2001 and 2016. The most common ones were CRF01_AE, CRF07_BC, and subtype B in Beijing during this period. The overall prevalence of TDR was 4.5% (95% confidence intervals[CI]: 3.6%–5.4%), with a declining trend over the period of spanning 2001 through 2016. In-depth class-specific analysis revealed that the prevalence of TDR for the nucleoside reverse-transcriptase inhibitors (NRTIs) was 1.0% (95% CI: 0.6–1.5), 0.9% (95% CI:0.6–1.4) for non-NRTIs and 2.8% (95% CI:2.1–3.5) for protease inhibitors. The prevalence of TDR was lower in individuals infected with the CRF07_BC HIV strain than those infected with CRF01_AE.

Conclusions

Our data showed that the HIV epidemic in Beijing displayed a high genetic heterogeneity and a low and declining prevalence of TDR. In sharp contrast to Europe and North America, the declining trend of TDR between 2001 through 2016 was noticed while there was a widespread distribution of antiretroviral treatment in Beijing, China.

Transmitted HIV drug resistance among individuals with newly diagnosed HIV infection: a multicenter observational study

OBJECTIVES

Fifteen years after the roll-out of antiretroviral treatment (ART) in China, there is limited information available on transmitted HIV drug resistance (TDR). This study aimed to characterize the epidemiology of TDR in China.

DESIGN

We conducted a prospective cross-sectional observational study.

METHODS

We analyzed the demographic, clinical, and virological data of individuals with newly diagnosed HIV infection using data from the Beijing HIV laboratory network collected between 2001 and 2017. We did population-based sequencing of the pol gene on plasma specimens and identified TDR mutations using the WHO list for surveillance of TDR mutations.

RESULTS

Data on TDR were available for 91% of the 10 115 individuals with newly diagnosed HIV infection tested, of whom 19.2% were from rural areas. The overall prevalence of TDR was 4.1% [95% confidence interval (CI): 3.7-4.5%], with a declining trend over the period 2001-2017. In the multivariable analysis, the risk of TDR differed significantly according to sex [odds ratio (OR) for women vs. men: 0.41, 95% CI: 0.22-0.69, P = 0.002]; infection type (OR for CRF07_BC vs. CRF01_AE: 0.24, 95% CI: 0.16-0.36, P < 0.001); and sampling period (OR for 2009-2012 vs. 2001-2008: 0.57, 95% CI: 0.41-0.79; P = 0.01), and was significantly higher among individuals from Hebei province than in those from Beijing (OR: 1.43, 95% CI: 1.05-1.96; P = 0.02).

CONCLUSION

In China, the prevalence of TDR among individuals with newly diagnosed HIV infection is relatively low. Trends in TDR should be assessed in other countries with a high TDR burden.

Human Immunodeficiency Virus Drug Resistance: 2018 Recommendations of the International Antiviral Society-USA Panel

Background

Contemporary antiretroviral therapies (ART) and management strategies have diminished both human immunodeficiency virus (HIV) treatment failure and the acquired resistance to drugs in resource-rich regions, but transmission of drug-resistant viruses has not similarly decreased. In low- and middle-income regions, ART roll-out has improved outcomes, but has resulted in increasing acquired and transmitted resistances. Our objective was to review resistance to ART drugs and methods to detect it, and to provide updated recommendations for testing and monitoring for drug resistance in HIV-infected individuals.

Methods

A volunteer panel of experts appointed by the International Antiviral (formerly AIDS) Society–USA reviewed relevant peer-reviewed data that were published or presented at scientific conferences. Recommendations were rated according to the strength of the recommendation and quality of the evidence, and reached by full panel consensus.

Results

Resistance testing remains a cornerstone of ART. It is recommended in newly-diagnosed individuals and in patients in whom ART has failed. Testing for transmitted integrase strand-transfer inhibitor resistance is currently not recommended, but this may change as more resistance emerges with widespread use. Sanger-based and next-generation sequencing approaches are each suited for genotypic testing. Testing for minority variants harboring drug resistance may only be considered if treatments depend on a first-generation nonnucleoside analogue reverse transcriptase inhibitor. Different HIV-1 subtypes do not need special considerations regarding resistance testing.

Conclusions

Testing for HIV drug resistance in drug-naive individuals and in patients in whom antiretroviral drugs are failing, and the appreciation of the role of testing, are crucial to the prevention and management of failure of ART.

Effectiveness of Transmitted Drug Resistance Testing Before Initiation of Antiretroviral Therapy in HIV-Positive Individuals

BACKGROUND

For people living with HIV, major guidelines in high-income countries recommend testing for transmitted drug resistance (TDR) to guide the choice of first-line antiretroviral therapy (ART). However, individuals who fail a first-line regimen can now be switched to one of several effective regimens. Therefore, the virological and clinical benefit of TDR testing needs to be evaluated.

METHODS

We included individuals from the HIV-CAUSAL Collaboration who enrolled <6 months of HIV diagnosis between 2006 and 2015, were ART-naive, and had measured CD4 count and HIV-RNA. Follow-up started at the date when all inclusion criteria were first met (baseline). We compared 2 strategies: (1) TDR testing within 3 months of baseline versus (2) no TDR testing. We used inverse probability weighting to estimate the 5-year proportion and hazard ratios (HRs) of virological suppression (confirmed HIV-RNA <50 copies/mL), and of AIDS or death under both strategies.

RESULTS

Of 25,672 eligible individuals (82% males, 52% diagnosed in 2010 or later), 17,189 (67%) were tested for TDR within 3 months of baseline. Of these, 6% had intermediate- or high-level TDR to any antiretroviral drug. The estimated 5-year proportion virologically suppressed was 77% under TDR testing and 74% under no TDR testing; HR 1.06 (95% confidence interval: 1.03 to 1.19). The estimated 5-year risk of AIDS or death was 6% under both strategies; HR 1.03 (95% confidence interval: 0.95 to 1.12).

CONCLUSIONS

TDR prevalence was low. Although TDR testing improved virological response, we found no evidence that it reduced the incidence of AIDS or death in first 5 years after diagnosis.

[Modern HIV treatment]

Human immunodeficiency virus (HIV) infection has become a chronic disease with a favourable prognosis if adequate antiretroviral therapy (ART) is applied. Therefore, each patient with HIV infection should be treated irrespectively of clinical symptoms or of immunological status. A combination of three active drugs that have to be taken life-long has been standard for many years. The regimen contains two nucleoside reverse transcriptase inhibitors plus either an integrase inhibitor, a boosted protease inhibitor, or a non-nucleoside reverse transcriptase inhibitor. Integrase inhibitors are recommended as the third partner of choice by recent guidelines due to their high efficacy and their favourable safety profile. Many combination drugs are now available which allow a simple treatment with few tablets and in many instances a one-pill combination per day is an option. Potential interactions with drugs given for other diseases have to be taken into account, especially if a pharmacological booster is part of the regimen. Combination therapy should be changed if either virological failure (HIV RNA >200 copies/ml) or drug-related adverse events occur. In special situations (e. g. pregnancy) highly experienced experts in the field should be consulted. Novel approaches for HIV therapy include dual therapy as well as treatment with long-acting substances. Beside therapy, antiretroviral drugs are used for prevention either as post-exposure prophylaxis or as pre-exposure prophylaxis.

HIV-1 Drug Resistance Among Ugandan Adults Attending an Urban Out-Patient Clinic

BACKGROUND

Little is known about prevalence of drug resistance among HIV-infected Ugandans, a setting with over 15 years of public sector access to antiretroviral therapy (ART) and where virological monitoring was only recently introduced.

SETTING

This study was conducted in the adults' out-patient clinic of the Infectious Diseases Institute, Kampala, Uganda.

METHODS

HIV genotyping was performed in ART-naive patients and in treatment-experienced patients on ART for ≥6 months with virological failure (≥1000 copies/mL).

RESULTS

A total of 152 ART-naive and 2430 ART-experienced patients were included. Transmitted drug resistance was detected in 9 (5.9%) patients. After a median time on ART of 4.7 years [interquartile range: 2.5-8.7], 190 patients (7.8%) had virological failure with a median viral load of 4.4 log10 copies per milliliter (interquartile range: 3.9-4.9). In addition, 146 patients had a viral load between 51 and 999 copies per milliliter. Most patients with virological failure (142, 74.7%) were on first-line ART. For 163 (85.8%) ART-experienced patients, genotype results were available. Relevant drug-resistance mutations were observed in 135 (82.8%), of which 103 (63.2%) had resistance to 2 drug classes, and 11 (6.7%) had resistance to all drug classes available in Uganda.

CONCLUSION

The prevalence of transmitted drug resistance was lower than recently reported by the WHO. With 92% of all patients virologically suppressed on ART, the prevalence of virological failure was low when a cutoff of 1000 copies per milliliter is applied, and is in line with the third of the 90-90-90 UNAIDS targets. However, most failing patients had developed multiclass drug resistance.

Trend of HIV transmitted drug resistance before and after implementation of HAART regimen restriction in the treatment of HIV-1 infected patients in southern Taiwan

Background

The use of fixed combination antiretroviral therapy with a low genetic barrier for the treatment of patients infected with human immunodeficiency virus (HIV) may affect the local HIV transmitted drug resistance (TDR) pattern. The present study aimed to investigate changes in the prevalence of HIV TDR following the implementation of a fixed regimen of HIV treatment in Taiwan in 2012.

Methods

TDR was measured in antiretroviral treatment-naïve HIV-1-infected individuals who participated in voluntary counseling and testing between 2007 and 2015 in southern Taiwan. Antiretroviral resistance mutations were interpreted using the HIVdb program from the Stanford University HIV Drug Resistance Database.

Results

Sequences were obtained from 377 consecutive individuals between 2007 and 2015. The overall prevalence rates of TDR HIV among the study population from 2007 to 2011 and 2012–2015 were 10.6 and 7.9%, respectively. Among the detected mutations, K103 N and V179D + K103R were more frequently observed after 2012. Four HIV-infected patients with K103 N variants were detected after 2012, and 4 of the 5 patients with V179D + K103R variants were found after 2012. No significant differences were observed in the TDRs among nucleoside reverse transcriptase inhibitors (NRTIs), non-NRTIs (NNRTIs), protease inhibitors, multiple drug resistance, and any drug resistance between period 1 (2007–2011) and period 2 (2012–2015).

Conclusions

A fixed treatment regimen with zidovudine/lamivudine + efavirenz or nevirapine as first-line therapy for treatment-naïve patients infected with HIV did not significantly increase the TDR during the 4-year follow-up period. Due to the increase in NNRTI resistance associated with mutations after 2012, a longer follow-up period and larger sample size are needed in future studies.

Characterisation of HIV-1 molecular transmission clusters among newly diagnosed individuals infected with non-B subtypes in Italy

OBJECTIVE

We evaluated the characteristics of HIV-1 molecular transmission clusters (MTCs) in 1890 newly diagnosed individuals infected with non-B subtypes between 2005 and 2017 in Italy.

METHODS

Phylogenetic analyses were performed on pol sequences to characterise subtypes/circulating recombinant forms and identify MTCs. MTCs were divided into small (SMTCs, 2-3 sequences), medium (MMTCs, 4-9 sequences) and large (LMTCs, ≥10 sequences). Factors associated with MTCs were evaluated using logistic regression analysis.

RESULTS

145 MTCs were identified and involved 666 individuals (35.2%); 319 of them (16.9%) were included in 13 LMTCs, 111 (5.9%) in 20 MMTCs and 236 (12.5%) in 112 SMTCs. Compared with individuals out of MTCs, individuals involved in MTCs were prevalently Italian (72.7% vs 30.9%, p<0.001), male (82.9% vs 62.3%, p<0.001) and men who have sex with men (MSM) (43.5% vs 14.5%, p<0.001). Individuals in MTCs were also younger (median (IQR) years: 41 (35-49) vs 43 (36-51), p<0.001) and had higher CD4 cell count in comparison with individuals out of MTCs (median (IQR): 10⁹/L: 0.4 (0.265-0.587) vs 0.246 (0.082-0.417), p<0.001). The viral load remained stable between the two groups (median (IQR) log₁₀ copies/mL: 4.8 (4.2-5.5) vs 5.0 (4.3-5.5), p=0.87). Logistic regression confirmed that certain factors such as being MSM, of Italian origin, younger age and higher CD4 cell count were significantly associated with MTCs.

CONCLUSIONS

Our findings show that HIV-1 newly diagnosed individuals infected with non-B subtypes are involved in several MTCs in Italy. These MTCs include mainly Italians and MSM and highlight the complex phenomenon characterising the HIV-1 spread. This is important especially in view of monitoring the HIV epidemic and guiding the public health response.

Dissecting HIV Virulence: Heritability of Setpoint Viral Load, CD4+ T-Cell Decline, and Per-Parasite Pathogenicity

Pathogen strains may differ in virulence because they attain different loads in their hosts, or because they induce different disease-causing mechanisms independent of their load. In evolutionary ecology, the latter is referred to as “per-parasite pathogenicity”. Using viral load and CD4+ T-cell measures from 2014 HIV-1 subtype B-infected individuals enrolled in the Swiss HIV Cohort Study, we investigated if virulence—measured as the rate of decline of CD4+ T cells—and per-parasite pathogenicity are heritable from donor to recipient. We estimated heritability by donor–recipient regressions applied to 196 previously identified transmission pairs, and by phylogenetic mixed models applied to a phylogenetic tree inferred from HIV pol sequences. Regressing the CD4+ T-cell declines and per-parasite pathogenicities of the transmission pairs did not yield heritability estimates significantly different from zero. With the phylogenetic mixed model, however, our best estimate for the heritability of the CD4+ T-cell decline is 17% (5–30%), and that of the per-parasite pathogenicity is 17% (4–29%). Further, we confirm that the set-point viral load is heritable, and estimate a heritability of 29% (12–46%). Interestingly, the pattern of evolution of all these traits differs significantly from neutrality, and is most consistent with stabilizing selection for the set-point viral load, and with directional selection for the CD4+ T-cell decline and the per-parasite pathogenicity. Our analysis shows that the viral genotype affects virulence mainly by modulating the per-parasite pathogenicity, while the indirect effect via the set-point viral load is minor.

Prevalence and persistence of transmitted drug resistance mutations in the German HIV-1 Seroconverter Study Cohort

The prevalence of transmitted drug resistance (TDR) in antiretroviral therapy (ART)-naïve individuals remains stable in most developed countries despite a decrease in the prevalence of acquired drug resistance. This suggests that persistence and further transmission of HIV-1 that encodes transmitted drug resistance mutations (TDRMs) is occurring in ART-naïve individuals. In this study, we analysed the prevalence and persistence of TDRMs in the protease and reverse transcriptase-sequences of ART-naïve patients within the German HIV-1 Seroconverter Study Cohort who were infected between 1996 and 2017. The prevalence of TDRMs and baseline susceptibility to antiretroviral drugs were assessed using the Stanford HIVdb list and algorithm. Mean survival times of TDRMs were calculated by Kaplan-Meier analysis. The overall prevalence of TDR was 17.2% (95% CI 15.7–18.6, N = 466/2715). Transmitted NNRTI resistance was observed most frequently with 7.8% (95% CI 6.8–8.8), followed by NRTI resistance (5.0%, 95% CI 4.2–5.9) and PI resistance (2.8%, 95% CI 2.2–3.4). Total TDR (OR = 0.89, p = 0.034) and transmitted NRTI resistance (OR = 0.65, p = 0.000) decreased between 1996 and 2017 but has remained stable during the last decade. Viral susceptibility to NNRTIs (6.5%-6.9% for individual drugs) was mainly reduced, while <3% of the recommended NRTIs and PIs were affected. The longest mean survival times were calculated for the NNRTI mutations K103N (5.3 years, 95% CI 4.2–5.6) and E138A/G/K (8.0 years, 95% CI 5.8–10.2 / 7.9 years, 95% CI 5.4–10.3 / 6.7 years, 95% CI 6.7–6.7) and for the NRTI mutation M41L (6.4 years, 95% CI 6.0–6.7).The long persistence of single TDRMs indicates that onward transmission from ART-naïve individuals is the main cause for TDR in Germany. Transmitted NNRTI resistance was the most frequent TDR, showing simultaneously the highest impact on baseline ART susceptibility and on TDRMs with prolonged persistence. These results give cause for concern regarding the use of NNRTI in first-line regimens.

Quantifying the drivers of HIV transmission and prevention in men who have sex with men: a population model-based analysis in Switzerland

OBJECTIVES

Despite the huge success of antiretroviral therapy (ART), there is an ongoing HIV epidemic among men who have sex with men (MSM) in resource-rich countries. Understanding the driving factors underlying this process is important for curbing the epidemic.

METHODS

We simulated the HIV epidemic in MSM in Switzerland by stratifying a mathematical model by CD4 count, the care cascade and condom use. The model was parametrised with clinical, epidemiological and behavioural data from the Swiss HIV Cohort Study and surveys in the HIV-negative population.

RESULTS

According to our model, 3.4% of the cases that would otherwise have occurred in 2008-2015 were prevented by early initiation of ART. Only 0.6% of the cases were attributable to a change in condom use in the HIV-positive population, as less usage is mainly seen in virally suppressed MSM. Most new infections were attributable to transmission from recently infected undiagnosed individuals. It was estimated that doubling the diagnosis rate would have resulted in 11.8% fewer cases in 2001-2015. Moreover, it was estimated that introducing pre-exposure prophylaxis (PrEP) for 50% of those MSM not using condoms with occasional partners would have resulted in 22.6% fewer cases in 2012-2015.

CONCLUSIONS

By combining observational data on the relevant epidemiological and clinical processes with a mathematical model, we showed that the 'test and treat' approach is most effective in reducing the number of new cases. Only a moderate population-level effect was estimated for early initiation of ART and a weak effect for the change in condom use of diagnosed MSM. Protecting HIV-negative individuals who are not using condoms with PrEP was shown to have a major impact.

Prevalence and Transmission Dynamics of HIV-1 Transmitted Drug Resistance in a Southeastern Cohort

Background

Transmitted drug resistance (TDR) compromises clinical management and outcomes. Transmitted drug resistance surveillance and identification of growing transmission clusters are needed in the Southeast, the epicenter of the US HIV epidemic. Our study investigated prevalence and transmission dynamics in North Carolina.

Methods

We analyzed surveillance drug resistance mutations (SDRMs) using partial pol sequences from patients presenting to 2 large HIV outpatient clinics from 1997 to 2014. Transmitted drug resistance prevalence was defined as ≥1 SDRMs among antiretroviral therapy (ART)–naïve patients. Binomial regression was used to characterize prevalence by calendar year, drug class, and demographic and clinical factors. We assessed the transmission networks of patients with TDR with maximum likelihood trees and Bayesian methods including background pol sequences (n = 15 246).

Results

Among 1658 patients with pretherapy resistance testing, ≥1 SDRMs was identified in 199 patients, with an aggregate TDR prevalence of 12% (95% confidence interval, 10% to 14%) increasing over time (P = .02). Resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs; 8%) was common, followed by nucleoside reverse transcriptase inhibitors (4%) and protease inhibitors (2%). Factors associated with TDR were being a man reporting sex with men, white race, young age, higher CD4 cell count, and being a member of a transmission cluster. Transmitted drug resistance was identified in 106 clusters ranging from 2 to 26 members. Cluster resistance was primarily NNRTI and dominated by ART-naïve patients or those with unknown ART initiation.

Conclusions

Moderate TDR prevalence persists in North Carolina, predominantly driven by NNRTI resistance. Most TDR cases were identified in transmission clusters, signifying multiple local transmission networks and TDR circulation among ART-naïve persons. Transmitted drug resistance surveillance can detect transmission networks and identify patients for enhanced services to promote early treatment.

Patterns of Transmitted Drug Resistance and Virological Response to First-line Antiretroviral Treatment Among Human Immunodeficiency Virus-Infected People Who Use Illicit Drugs in a Canadian Setting

Background

Transmitted drug resistance (TDR) may compromise response to antiretroviral therapy (ART). However, there are limited data on TDR patterns and impacts among people who use illicit drugs (PWUD).

Methods

Data were drawn from 2 prospective cohorts of PWUD in Vancouver, Canada. We characterized patterns of TDR among human immunodeficiency virus (HIV)-infected PWUD, and assessed its impacts on first-line ART virological outcomes.

Results

Between 1996 and 2015, among 573 ART-naive PWUD (18% with recent HIV infection), the overall TDR prevalence was 9.8% (95% confidence interval [CI], 7.3%-12.2%), with an increasing trend over time, from 8.5% in 1996-1999 to 21.1% in 2010-2015 (P = .003), mainly driven by resistance to nonnucleoside reverse transcriptase inhibitors (NNRTIs). TDR-associated mutations were more common for NNRTIs (5.4%), followed by nucleoside reverse transcriptase inhibitors (3.0%) and protease inhibitors (1.9%). TDR prevalence was lower among recently infected PWUD (adjusted odds ratio, 0.39 [95% CI, .15-.87]). Participants with TDR had higher risk of virological failure than those without TDR (log-rank P = .037) in the first year of ART.

Conclusions

Between 1996 and 2015, TDR prevalence increased significantly among PWUD in Vancouver. Higher risk of virological failure among PWUD with TDR may be explained by some inappropriate ART prescribing, as well as undetected minority resistant variants in participants with chronic HIV infection. Our findings support baseline resistance testing early in the course of HIV infection to guide ART selection among PWUD in our setting.

Distinct, IgG1-driven antibody response landscapes demarcate individuals with broadly HIV-1 neutralizing activity

Kadelka et al. show that parameters linked with HIV-1 broadly neutralizing antibody (bnAb) development shape HIV-1–binding antibody responses in an antigen and IgG subclass dependent manner. Identified HIV-1 antibody signature landscapes reveal a shift toward IgG1-driven responses in bnAb developers.

Understanding pathways that promote HIV-1 broadly neutralizing antibody (bnAb) induction is crucial to advance bnAb-based vaccines. We recently demarcated host, viral, and disease parameters associated with bnAb development in a large HIV-1 cohort screen. By establishing comprehensive antibody signatures based on IgG1, IgG2, and IgG3 activity to 13 HIV-1 antigens in 4,281 individuals in the same cohort, we now show that the same four parameters that are significantly linked with neutralization breadth, namely viral load, infection length, viral diversity, and ethnicity, also strongly influence HIV-1–binding antibody responses. However, the effects proved selective, shaping binding antibody responses in an antigen and IgG subclass–dependent manner. IgG response landscapes in bnAb inducers indicated a differentially regulated, IgG1-driven HIV-1 antigen response, and IgG1 binding of the BG505 SOSIP trimer proved the best predictor of HIV-1 neutralization breadth in plasma. Our findings emphasize the need to unravel immune modulators that underlie the differentially regulated IgG response in bnAb inducers to guide vaccine development.

HIV-1 integrase strand-transfer inhibitor resistance in southern Taiwan

The use of antiretroviral therapy has reduced rates of mortality and morbidity in patients with human immunodeficiency virus/acquired immune deficiency syndrome(HIV/AIDS). However, transmission of drug-resistant strains poses a challenge to control the spread of HIV-1. Primary resistance to integrase strand-transfer inhibitors (INSTIs) is rare despite their increased use. The prevalence of transmitted drug resistance (TDR) to INSTIs was 0.9% in northern Taiwan. This study was to analyse the prevalence and risk factors of TDR to INSTIs in southern Taiwan. In this study, we enrolled antiretroviral treatment-naïve HIV-1-infected subjects who underwent voluntary counselling and testing from 2013 to 2016 in southern Taiwan. Genotypic drug resistance, coreceptor tropism (CRT) and INSTI resistance were determined. Logistic regression was used to analyse the risk factors for INSTI polymorphic substitution. Sequences were obtained from 184 consecutive individuals, of whom 96.7% were men who have sex with men and 3.3% were heterosexual. Of the patients, 10% (19/183) had hepatitis B and 33.3% (61/183) had syphilis infection. Subtype B HIV-1 strains were found in 96.1% of the patients. Fifteen patients (8.4%, 15/178) harboured nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors or protease inhibitors resistance. CCR-5 coreceptors were used by 71.4% (130/184) of the patients. None of the patients had INSTI resistance-associated mutations, however 16 patients had INSTI polymorphic substitutions, and they were associated with a higher HIV viral load (p = 0.03, OR 2.4, CI 1.1–5.3) and syphilis infection (p = 0.03, OR 3.7, CI 1.1–12.0). In conclusion, no signature INSTI resistance-associated mutations were detected in our cohort. Continued monitoring of TDR to INSTI is needed due to the increased use of INSTIs.

Lipodystrophy Increases the Risk of CKD Development in HIV-Positive Patients in Switzerland: The LIPOKID Study

Introduction

Antiretroviral therapy has improved the life expectancy of patients living with HIV. However, lipodystrophy syndrome (LD) remains prevalent, affecting mostly patients treated with first-generation antiretroviral drugs. This syndrome is characterized by changes in body fat distribution with or without associated metabolic changes. Here, we studied whether clinically evaluated LD is independently associated with chronic kidney disease (CKD) development (sustained estimated glomerular filtration rate [eGFR] < 60 ml/min per 1.73 m²) in HIV-positive patients.

Methods

We conducted a prospective cohort study (the LIPOKID Study) among all the patients from the Swiss HIV Cohort Study (SHCS) with an eGFR >60 ml/min per 1.73 m² upon their entry into the cohort with more than 3 months of follow-up from January 2002 to August 2016. Cox regression models were used to estimate the association between LD and CKD development.

Results

Among the 5384 patients included, 1341 (24.9%) developed LD during the follow-up. The mean follow-up time was 72.3 months (SD ±48.4). In total, 252 patients (4.7%) reached the primary endpoint after a median time of 51.3 months (±SD 39.9 months) from inclusion. A diagnosis of LD significantly increased the risk of an eGFR on univariate analysis (hazard ratio [HR] = 2.72; 95% confidence interval [95% CI] = 2.07−3.58; P < 0.001) and remained significantly higher after adjustment for known HIV and non-HIV risk factors for CKD (HR = 2.37; 95% CI = 1.67−3.36; P < 0.001). The effect of LD on CKD was not mediated through the use of nephrotoxic antiretroviral drugs.

Conclusion

Lipodystrophy syndrome is independently associated with CKD after adjustment for previously reported risk factors.

Transmission of HIV-1 drug resistance mutations within partner-pairs: A cross-sectional study of a primary HIV infection cohort

BACKGROUND

Transmission of human immunodeficiency virus type 1 (HIV-1) drug resistance mutations, particularly that of minority drug-resistant variants, remains poorly understood. Population-based studies suggest that drug-resistant HIV-1 is less transmissible than drug-susceptible viruses. We compared HIV-1 drug-resistant genotypes among partner-pairs in order to assess the likelihood of transmission of drug resistance mutations and investigate the role of minority variants in HIV transmission.

METHODS AND FINDINGS

From 1992-2010, 340 persons with primary HIV-1 infection and their partners were enrolled into observational research studies at the University of Washington Primary Infection Clinic (UWPIC). Out of 50 partner-pairs enrolled, 36 (72%) transmission relationships were confirmed by phylogenetic distance analysis of HIV-1 envelope (env) sequences, and 31 partner-pairs enrolled after 1995 met criteria for this study. Drug resistance mutations in the region of the HIV-1 polymerase gene (pol) that encodes protease and reverse transcriptase were assessed by 454-pyrosequencing. In 25 partner-pairs where the transmission direction could be determined, 12 (48%) transmitters had 1-4 drug resistance mutations (23 total) detected in their HIV-1 populations at a median frequency of 6.0% (IQR 1.5%-98.7%, range 1.0%-99.6%). Of 10 major mutations detected in five transmitters at a frequency >95%, 100% (95% CI 69.2%-100%) were detected in recipients. All of these transmitters were antiretroviral (ARV)-naïve at the time of specimen collection. Fourteen mutations (eight major mutations and six accessory mutations) were detected in nine transmitters at low frequencies (1.0%-11.8%); four of these transmitters had previously received ARV therapy. Two (14% [95% CI 1.8%-42.8%]) G73S accessory mutations were detected in both transmitter and recipient. This number is not significantly different from the number expected based on the observed frequencies of drug-resistant viruses in transmitting partners. Limitations of this study include the small sample size and uncertainties in determining the timing of virus transmission and mutation history.

CONCLUSIONS

Drug-resistant majority variants appeared to be commonly transmitted by ARV-naïve participants in our analysis and may contribute significantly to transmitted drug resistance on a population level. When present at low frequency, no major mutation was observed to be shared between partner-pairs; identification of accessory mutations shared within a pair could be due to transmission, laboratory artifact, or apolipoprotein B mRNA-editing enzyme, catalytic polypeptides (APOBECs), and warrants further study.

Quantifying the fitness cost of HIV-1 drug resistance mutations through phylodynamics

Drug resistant HIV is a major threat to the long-term efficacy of antiretroviral treatment. Around 10% of ART-naïve patients in Europe are infected with drug-resistant HIV type 1. Hence it is important to understand the dynamics of transmitted drug resistance evolution. Thanks to routinely performed drug resistance tests, HIV sequence data is increasingly available and can be used to reconstruct the phylogenetic relationship among viral lineages. In this study we employ a phylodynamic approach to quantify the fitness costs of major resistance mutations in the Swiss HIV cohort. The viral phylogeny reflects the transmission tree, which we model using stochastic birth–death-sampling processes with two types: hosts infected by a sensitive or resistant strain. This allows quantification of fitness cost as the ratio between transmission rates of hosts infected by drug resistant strains and transmission rates of hosts infected by drug sensitive strains. The resistance mutations 41L, 67N, 70R, 184V, 210W, 215D, 215S and 219Q (nRTI-related) and 103N, 108I, 138A, 181C, 190A (NNRTI-related) in the reverse trancriptase and the 90M mutation in the protease gene are included in this study. Among the considered resistance mutations, only the 90M mutation in the protease gene was found to have significantly higher fitness than the drug sensitive strains. The following mutations associated with resistance to reverse transcriptase inhibitors were found to be less fit than the sensitive strains: 67N, 70R, 184V, 219Q. The highest posterior density intervals of the transmission ratios for the remaining resistance mutations included in this study all included 1, suggesting that these mutations do not have a significant effect on viral transmissibility within the Swiss HIV cohort. These patterns are consistent with alternative measures of the fitness cost of resistance mutations. Overall, we have developed and validated a novel phylodynamic approach to estimate the transmission fitness cost of drug resistance mutations.

The introduction of antiretroviral therapy (ART) has decreased mortality and morbidity rates among HIV-infected people, and improved their quality of life. In fact, the WHO states that antiretroviral therapy programmes averted an estimated 7.8 million deaths worldwide between 2000 and 2014. However, the antiretroviral regimen prescribed to a patient may be unable to control HIV infection. Factors that can contribute to treatment failure include drug resistance, drug toxicity, or poor treatment adherence. In this study we aim to understand the dynamics of transmitted drug resistance by analysing the viral sequence data that was collected for resistance testing. We present a novel approach to quantify how drug resistance impacts virus lineage transmissibility, how fast resistance mutations evolve in sensitive strains and how fast they revert back to the sensitive type. We apply our approach to the Swiss HIV cohort study, and obtain patterns of viral transmission fitness that are consistent with alternative, harder to obtain measures of fitness.

Assessment of HIV molecular surveillance capacity in the European Union, 2016

IntroductionExpanding access to HIV antiretroviral treatment is expected to decrease HIV incidence and acquired immunodeficiency syndrome (AIDS) mortality. However, this may also result in increased HIV drug resistance (DR). Better monitoring and surveillance of HIV DR is required to inform treatment regimens and maintain the long term effectiveness of antiretroviral drugs. As there is currently no formal European Union (EU)-wide collection of HIV DR data, this study aimed to assess the current HIV molecular surveillance capacity in EU/European Economic Area (EEA) countries in order to inform the planning of HIV DR monitoring at EU level. Methods: Thirty EU/EEA countries were invited to participate in a survey on HIV molecular surveillance capacity, which also included laboratory aspects. Results: Among 21 responding countries, 13 reported using HIV sequence data (subtype and/or DR) for surveillance purposes at national level. Of those, nine stated that clinical, epidemiological and sequence data were routinely linked for analysis. Discussion/conclusion: We identified similarities between existing HIV molecular surveillance systems, but also found important challenges including human resources, data ownership and legal issues that would need to be addressed.Information on capacities should allow better planning of the phased introduction of HIV DR surveillance at EU/EEA level.

Pretreatment integrase strand transfer inhibitor resistance in North Carolina from 2010-2016

OBJECTIVE

We sought to define the prevalence of pretreatment integrase strand transfer inhibitor (INSTI) resistance and assess the transmission networks of those with pretreatment INSTI resistance.

DESIGN

A retrospective cohort study of HIV-positive patients with genotypic resistance testing sent to a single referral laboratory in North Carolina between 2010 and 2016.

METHODS

We linked genotype and public health data for in-care HIV-positive individuals to determine the prevalence of INSTI resistance among treatment-naive (defined as those with a first genotype ≤3 months after diagnosis) and treatment-experienced (defined as those with a first genotype >3 months after diagnosis) patients. We performed molecular and phylogenetic analyses to assess whether pretreatment INSTI resistance mutations represented clustered HIV transmission.

RESULTS

Of 8825 individuals who contributed sequences for protease, reverse transcriptase, or INSTI genotypic resistance testing during the study period, 2784 (31%) contributed at least one sequence for INSTI resistance testing. Of these, 840 were treatment-naive individuals and 20 [2.4%, 95% confidence interval (CI): 1.5, 3.6%] had INSTI mutations; only two (0.2%, 95% CI: 0.02, 0.9%) had major mutations. Of 1944 treatment-experienced individuals, 9.6% (95% CI: 8.3, 11.0%) had any INSTI mutation and 7.0% (95% CI: 5.9, 8.3%) had major mutations; the prevalence of INSTI mutations among treatment-experienced patients decreased overtime (P < 0.001). In total 12 of 20 individuals with pretreatment INSTI mutations were part of 10 molecular transmission clusters; only one cluster shared identical minor mutations.

CONCLUSION

The prevalence of major pretreatment INSTI resistance is very low. Pretreatment INSTI mutations do not appear to represent clustered HIV transmission.

Prevalence of drug resistance among HIV-1 treatment-naive patients in Greece during 2003-2015: Transmitted drug resistance is due to onward transmissions

BACKGROUND

The prevalence of HIV-1 drug resistance among treatment-naïve patients ranges between 8.3% and 15% in Europe and North America. Previous studies showed that subtypes A and B were the most prevalent in the Greek HIV-1 epidemic. Our aim was to estimate the prevalence of resistance among drug naïve patients in Greece and to investigate the levels of transmission networking among those carrying resistant strains.

METHODS

HIV-1 sequences were determined from 3428 drug naïve HIV-1 patients, in Greece sampled during 01/01/2003-30/6/2015. Transmission clusters were estimated by means of phylogenetic analysis including as references sequences from patients failing antiretroviral treatment in Greece and sequences sampled globally.

RESULTS

The proportion of sequences with SDRMs was 5.98% (n=205). The most prevalent SDRMs were found for NNRTIs (3.76%), followed by N(t)RTIs (2.28%) and PIs (1.02%). The resistance prevalence was 22.2% based on all mutations associated with resistance estimated using the HIVdb resistance interpretation algorithm. Resistance to NNRTIs was the most common (16.9%) followed by PIs (4.9%) and N(t)RTIs (2.8%). The most frequently observed NNRTI resistant mutations were E138A (7.7%), E138Q (4.0%), K103N (2.3%) and V179D (1.3%). The majority of subtype A sequences (89.7%; 245 out of 273) with the dominant NNRTI resistance mutations (E138A, K103N, E138Q, V179D) were found to belong to monophyletic clusters suggesting regional dispersal. For subtype B, 68.1% (139 out of 204) of resistant strains (E138A, K103N, E138Q V179D) belonged to clusters. For N(t)RTI-resistance, evidence for regional dispersal was found for 27.3% and 21.6% of subtype A and B sequences, respectively.

CONCLUSIONS

The TDR rate based on the prevalence of SDRM is lower than the average rate in Europe. However, the prevalence of NNRTI resistance estimated using the HIVdb approach, is high in Greece and it is mostly due to onward transmissions among drug-naïve patients.

Longitudinal trends of HIV drug resistance in a large Canadian cohort, 1996-2016

OBJECTIVES

We aim to identify long-term trends in HIV drug resistance before and after combined antiretroviral therapy (cART) initiation.

METHODS

IAS-USA (2015) mutations were identified in 23 271 HIV protease-reverse transcriptase sequences from 6543 treatment naïve adults in British Columbia. Participants who started cART between 1996 and 2014 were followed until April 2016. Equality of proportions test was used to compare the percentage of participants with acquired drug resistance (ADR) or transmitted drug resistance (TDR) in 1996, to those in 2014. Kaplan-Meier was used to estimate time to ADR in four drug resistance categories. Multivariable regression odds ratios (OR) of ADR for select clinical variables were determined by 5-year eras of cART initiation.

RESULTS

The proportion of individuals with ADR declined from 39% (51/132) to 3% (8/322) in 1996-2014 (p <0.0001), while the proportion with TDR increased from 12% (16/132) to 18% (59/322) (p 0.14). The estimated proportions of individuals with ADR rose to 29% (NNRTI), 28% (3TC/FTC), 14% (other nRTI), and 7% (PI) after >16 years of therapy. After 5 years on therapy, participants initiating cART in 1996-2000 had 5.5-times more 3TC/FTC ADR, 5.3-times more other nRTI ADR, 4.7-times more NNRTI ADR, and 24-times more PI ADR than those starting in 2011-2014. The individuals with highest odds of developing ADR in 1996-2010 were adherent to regimens at levels between 60% and 80%, which shifted to <40% adherent in 2011-2014.

CONCLUSIONS

HIV drug resistance transitioned from being primarily selected de-novo to being driven by TDR. Among those who started treatment in the past 5 years, ADR is rare and observed mostly in the lowest adherence strata.

Decreasing prevalence of transmitted drug resistance among ART-naive HIV-1-infected patients in Iceland, 1996-2012

Introduction: Resistance to antiretroviral drugs can complicate the management of HIV-1 infection and impair control of its spread. The aim of the current study was to investigate the prevalence and transmission of HIV-1 drug resistance among 106 antiretroviral therapy (ART)-naïve patients diagnosed in Iceland (1996-2012). Methods: HIV-1 polymerase sequences were analysed using the Calibrated Population Resistance tool. Domestic spread of transmitted drug resistance (TDR) was investigated through maximum likelihood and Bayesian approaches. Results: Among ART-naïve patients, the prevalence of TDR to any of the following classes (NRTIs, NNRTIs and PIs) was 8.5% (95% CI: 4.5%- 15.4%): 6.6% to NRTIs, 0.9% to NNRTIs, and 1.9% to PIs. The most frequent NRTI mutation detected was T215C/D (n=7, 5.7%). The only NNRTI mutation detected was K103N (n=1, 0.9%). PI mutations detected were M46I (n=1, 0.9%) and L90M (n=1, 0.9%). Six patients harbouring T215C/D, were linked in a supported phylogenetic cluster. No significant association was found between TDR and demographic or risk groups. Trend analysis showed a decrease in the prevalence of TDR (1996-2012, p=0.003). Conclusions: TDR prevalence in Iceland was at a moderate level and decreased during 1996-2012. Screening for TDR is recommended to limit its local spread and to optimize HIV-1 therapy. Abbreviations: ART: Anti-retroviral therapy; ARV: antiretroviral; ATV/r: atazanavir/ritonavir; AZT: azidothymidine; BEAST: Bayesian evolutionary analysis by sampling trees; CI: confidence interval; CPR: calibrated population resistance; CRF: circulating recombinant form; d4T: stavudine; EFV: efavirenz; FET: Fishers' exact test; FPV/r: fosamprenavir/ritonavir; HET: heterosexual; IDU: injection drug use; IDV/r: indinavir/ritonavir; LPV/r: lopinavir/ritonavir; MSM: men who have sex with men; M-W: Mann-Whitney U test; NFV: nelfinavir; NNRTIs: non-nucleoside reverse transcriptase inhibitors; NRTIs: nucleoside reverse transcriptase inhibitors; NVP: nevirapine; PIs: protease inhibitors; pol: polymerase gene; SDRM: surveillance drug resistance mutation; SQV/r: saquinavir/ritonavir; TDR: transmitted drug resistance.

Mining for pairs: shared clinic visit dates identify steady HIV-positive partnerships

OBJECTIVES

Here we examined the hypothesis that some stable HIV-infected partnerships can be found in cohort studies, as the patients frequently attend the clinic visits together.

METHODS

Using mathematical approximations and shuffling to derive the probabilities of sharing a given number of visits by chance, we identified and validated couples that may represent either transmission pairs or serosorting couples in a stable relationship.

RESULTS

We analysed 434 432 visits for 16 139 Swiss HIV Cohort Study patients from 1990 to 2014. For 89 pairs, the number of shared visits exceeded the number expected. Of these, 33 transmission pairs were confirmed on the basis of three criteria: an extensive phylogenetic tree, a self-reported steady HIV-positive partnership, and risk group affiliation. Notably, 12 of the validated transmission pairs (36%; 12 of 33) were of a mixed ethnicity with a large median age gap [17.5 years; interquartile range (IQR) 11.8-22 years] and these patients harboured HIV-1 of predominantly non-B subtypes, suggesting imported infections.

CONCLUSIONS

In the context of the surge in research interest in HIV transmission pairs, this simple method widens the horizons of research on within-pair quasi-species exchange, transmitted drug resistance and viral recombination at the biological level and targeted prevention at the public health level.

Recent trends and patterns in HIV-1 transmitted drug resistance in the United Kingdom

OBJECTIVES

Transmission of drug-resistant HIV-1 has decreased in the UK since the early 2000s. This analysis reports recent trends and characteristics of transmitted drug resistance (TDR) in the UK from 2010 to 2013.

METHODS

Resistance tests conducted in antiretroviral treatment (ART)-naïve individuals between 2010 and 2013 were analysed for the presence of transmitted drug resistance mutations (TDRMs), defined as any mutations from a modified 2009 World Health Organization surveillance list, or a modified 2013 International Antiviral Society-USA list for integrase tests. Logistic regression was used to examine associations between demographics and the prevalence of TDRMs.

RESULTS

TDRMs were observed in 1223 (7.5%) of 16 425 individuals; prevalence declined from 8.1% in 2010 to 6.6% in 2013 (P = 0.02). The prevalence of TDRMs was higher among men who have sex with men (MSM) compared with heterosexual men and women (8.7% versus 6.4%, respectively) with a trend for decreasing TDRMs among MSM (P = 0.008) driven by a reduction in nucleoside reverse transcriptase inhibitor (NRTI)-related mutations. The most frequently detected TDRMs were K103N (2.2%), T215 revertants (1.6%), M41L (0.9%) and L90M (0.7%). Predicted phenotypic resistance to first-line ART was highest to the nonnucleoside reverse transcriptase inhibitors (NNRTIs) rilpivirine and efavirenz (6.2% and 3.4%, respectively) but minimal to NRTIs, including tenofovir, and protease inhibitors (PIs). No major integrase TDRMs were detected among 101 individuals tested while ART-naïve.

CONCLUSIONS

We observed a decrease in TDRMs in recent years. However, this was confined to the MSM population and rates remained stable in those with heterosexually acquired HIV infection. Resistance to currently recommended first-line ART, including integrase inhibitors, remained reassuringly low.

Trends and predictors of HIV-1 acquired drug resistance in Minas Gerais, Brazil: 2002-2012

Several studies show that the prevalence of multidrug-resistant HIV-1 virus is declining over time. A retrospective cohort study was carried out to evaluate the trends of drug resistance in antiretroviral treatment-exposed individuals in a state of a middle-income country, Minas Gerais, southeast region of Brazil. We analyzed 2115 HIV-1 sequences from 2002 up to 2012, from 52 cities of Minas Gerais. The groups were analyzed according to the definitions: "IAS - 3 class mutations", if ≥1 drug resistance mutation from IAS 2015 list (DRM) was present in each class; "No fully susceptible drugs" as the absence of any fully susceptible drug in Stanford algorithm; and "GSS≥2″, when a maximum calculated GSS (genotypic susceptibility score) was ≥2 or ≥3, counting only drugs available in Brazil and USA at given calendar years. Time trends of resistance were analyzed by Cochran-Armitage test. We observed a decrease in the rate resistance mutations for PI, NRTI, "IAS - 3 class mutations", and "No fully susceptible drugs" over these 11 years, from 69.2% to 20.7%, 92.3% to 90.2%, 46.2% to 22.5%, and 12.8% to 5.7%, respectively (p<0.05). Resistance to NNRTI increased from 74.4% to 81.6%, mainly because of K103N mutation. The GSS score ≥2 increased during the years from 35.9% to 87.3% (p<0.001). We demonstrate that resistance to PI and to the three main classes simultaneously are declining, although the number of patients on of antiretroviral therapy has doubled in the last ten years in Brazil (125,000 in 2002 to 400,000 in 2014). Broader resistance testing and the availability of more therapeutic options might have influenced this decline. The increase in NNRTI resistance can limit this class as first line treatment in Brazil in the future.

In-depth analysis of HIV-1 drug resistance mutations in HIV-infected individuals failing first-line regimens in West and Central Africa

OBJECTIVE

In resource-limited countries, antiretroviral therapy (ART) has been scaled up, but individual monitoring is still suboptimal. Here, we studied whether or not ART had an impact on the frequency and selection of drug resistance mutations (DRMs) under these settings. We also examined whether differences exist between HIV-1 genetic variants.

DESIGN

A total of 3736 sequences from individuals failing standard first-line ART (n = 1599, zidovudine/stavudine + lamivudine + neviparine/efavirenz) were analyzed and compared with sequences from reverse transcriptase inhibitor (RTI)-naive individuals (n = 2137) from 10 West and Central African countries.

METHODS

Fisher exact tests and corrections for multiple comparisons were used to assess the significance of associations.

RESULTS

All RTI-DRM from the 2015 International Antiviral Society list, except F227C, and nine mutations from other expert lists were observed to confer extensive resistance and cross-resistance. Five additional independently selected mutations (I94L, L109I, V111L, T139R and T165L) were statistically associated with treatment. The proportion of sequences with multiple mutations and the frequency of all thymidine analog mutations, M184V, certain NNRTIS, I94L and L109I showed substantial increase with time on ART. Only one nucleoside and two nonnucleoside RTI-DRMs differed by subtype/circulating recombinant form.

CONCLUSION

This study validates the global robustness of the actual DRM repertoire, in particular for circulating recombinant form 02 predominating in West and Central Africa, despite our finding of five additional selected mutations. However, long-term ART without virological monitoring clearly leads to the accumulation of mutations and the emergence of additional variations, which limit drug options for treatment and can be transmitted. Improved monitoring and optimization of ART are necessary for the long-term effectiveness of ART.

Reporting on the prevalence of antiretroviral drug resistance in a regional HIV population over 20 years: a word of caution

BACKGROUND

Failure to achieve complete viral suppression with antiretroviral drugs (ARV) may lead to uncontrolled HIV replication, ARV resistance and negative outcomes. Monitoring and reporting of HIV resistance trends is important but problematic. We examined prevalent resistance rates in an HIV population over 20 years and document how rates may appear to vary greatly based solely on which parameters are utilized.

METHODS

We determined the annual use of genotypic antiretroviral resistance testing (GART) from 1995 to 2014 for all patients receiving HIV care in southern Alberta, Canada, and the presence of resistance mutations in those tested. The impact on prevalent resistance rates of using cumulative or latest GART was also determined.

RESULTS

Between 1995 and 2014, the number of patients with GART increased from <1% to 71%. Prevalent resistance in patients with GART decreased from a high of 52% in 2003 to 25.8% in 2014. However, if prevalence rates were reported using all active patients as denominator, including those without GART, prevalence increased from 0.7% to 18.5%. Prevalence rates were 7% to 9% higher in any given year if cumulative GART rather than latest GART results were used.

CONCLUSIONS

While prevalence resistance rates are decreasing, the precise rates being reported may vary due to increasing number of patients tested annually, using either the entire population as denominator or only patients with GART, and using either last or cumulative GART. Defining these parameters is critical if prevalence is to be compared over time or between HIV populations.

Determinants of HIV-1 broadly neutralizing antibody induction

Broadly neutralizing antibodies (bnAbs) are a focal component of HIV-1 vaccine design, yet basic aspects of their induction remain poorly understood. Here we report on viral, host and disease factors that steer bnAb evolution using the results of a systematic survey in 4,484 HIV-1-infected individuals that identified 239 bnAb inducers. We show that three parameters that reflect the exposure to antigen-viral load, length of untreated infection and viral diversity-independently drive bnAb evolution. Notably, black participants showed significantly (P = 0.0086-0.038) higher rates of bnAb induction than white participants. Neutralization fingerprint analysis, which was used to delineate plasma specificity, identified strong virus subtype dependencies, with higher frequencies of CD4-binding-site bnAbs in infection with subtype B viruses (P = 0.02) and higher frequencies of V2-glycan-specific bnAbs in infection with non-subtype B viruses (P = 1 × 10^-5). Thus, key host, disease and viral determinants, including subtype-specific envelope features that determine bnAb specificity, remain to be unraveled and harnessed for bnAb-based vaccine design.

A Direct Comparison of Two Densely Sampled HIV Epidemics: The UK and Switzerland

Phylogenetic clustering approaches can elucidate HIV transmission dynamics. Comparisons across countries are essential for evaluating public health policies. Here, we used a standardised approach to compare the UK HIV Drug Resistance Database and the Swiss HIV Cohort Study while maintaining data-protection requirements. Clusters were identified in subtype A1, B and C pol phylogenies. We generated degree distributions for each risk group and compared distributions between countries using Kolmogorov-Smirnov (KS) tests, Degree Distribution Quantification and Comparison (DDQC) and bootstrapping. We used logistic regression to predict cluster membership based on country, sampling date, risk group, ethnicity and sex. We analysed >8,000 Swiss and >30,000 UK subtype B sequences. At 4.5% genetic distance, the UK was more clustered and MSM and heterosexual degree distributions differed significantly by the KS test. The KS test is sensitive to variation in network scale, and jackknifing the UK MSM dataset to the size of the Swiss dataset removed the difference. Only heterosexuals varied based on the DDQC, due to UK male heterosexuals who clustered exclusively with MSM. Their removal eliminated this difference. In conclusion, the UK and Swiss HIV epidemics have similar underlying dynamics and observed differences in clustering are mainly due to different population sizes.

Tracing HIV-1 transmission: envelope traits of HIV-1 transmitter and recipient pairs

BACKGROUND

Mucosal HIV-1 transmission predominantly results in a single transmitted/founder (T/F) virus establishing infection in the new host despite the generally high genetic diversity of the transmitter virus population. To what extent HIV-1 transmission is a stochastic process or driven by selective forces that allow T/F viruses best to overcome bottlenecks in transmission has not been conclusively resolved. Building on prior investigations that suggest HIV-1 envelope (Env) features to contribute in the selection process during transmission, we compared phenotypic virus characteristics of nine HIV-1 subtype B transmission pairs, six men who have sex with men and three male-to-female transmission pairs.

RESULTS

All recipients were identified early in acute infection and harbored based on extensive sequencing analysis a single T/F virus allowing a controlled analysis of virus properties in matched transmission pairs. Recipient and transmitter viruses from the closest time point to transmission showed no signs of selection for specific Env modifications such as variable loop length and glycosylation. Recipient viruses were resistant to circulating plasma antibodies of the transmitter and also showed no altered sensitivity to a large panel of entry inhibitors and neutralizing antibodies. The recipient virus did not consistently differ from the transmitter virus in terms of entry kinetics, cell-cell transmission and replicative capacity in primary cells. Our paired analysis revealed a higher sensitivity of several recipient virus isolates to interferon-α (IFNα) which suggests that resistance to IFNα cannot be a general driving force in T/F establishment.

CONCLUSIONS

With the exception of increased IFNα sensitivity, none of the phenotypic virus properties we investigated clearly distinguished T/F viruses from their matched transmitter viruses supporting the notion that at least in subtype B infection HIV-1 transmission is to a considerable extent stochastic.

Antiretroviral Drugs for Treatment and Prevention of HIV Infection in Adults: 2016 Recommendations of the International Antiviral Society-USA Panel

IMPORTANCE

New data and therapeutic options warrant updated recommendations for the use of antiretroviral drugs (ARVs) to treat or to prevent HIV infection in adults.

OBJECTIVE

To provide updated recommendations for the use of antiretroviral therapy in adults (aged ≥18 years) with established HIV infection, including when to start treatment, initial regimens, and changing regimens, along with recommendations for using ARVs for preventing HIV among those at risk, including preexposure and postexposure prophylaxis.

EVIDENCE REVIEW

A panel of experts in HIV research and patient care convened by the International Antiviral Society-USA reviewed data published in peer-reviewed journals, presented by regulatory agencies, or presented as conference abstracts at peer-reviewed scientific conferences since the 2014 report, for new data or evidence that would change previous recommendations or their ratings. Comprehensive literature searches were conducted in the PubMed and EMBASE databases through April 2016. Recommendations were by consensus, and each recommendation was rated by strength and quality of the evidence.

FINDINGS

Newer data support the widely accepted recommendation that antiretroviral therapy should be started in all individuals with HIV infection with detectable viremia regardless of CD4 cell count. Recommended optimal initial regimens for most patients are 2 nucleoside reverse transcriptase inhibitors (NRTIs) plus an integrase strand transfer inhibitor (InSTI). Other effective regimens include nonnucleoside reverse transcriptase inhibitors or boosted protease inhibitors with 2 NRTIs. Recommendations for special populations and in the settings of opportunistic infections and concomitant conditions are provided. Reasons for switching therapy include convenience, tolerability, simplification, anticipation of potential new drug interactions, pregnancy or plans for pregnancy, elimination of food restrictions, virologic failure, or drug toxicities. Laboratory assessments are recommended before treatment, and monitoring during treatment is recommended to assess response, adverse effects, and adherence. Approaches are recommended to improve linkage to and retention in care are provided. Daily tenofovir disoproxil fumarate/emtricitabine is recommended for use as preexposure prophylaxis to prevent HIV infection in persons at high risk. When indicated, postexposure prophylaxis should be started as soon as possible after exposure.

CONCLUSIONS AND RELEVANCE

Antiretroviral agents remain the cornerstone of HIV treatment and prevention. All HIV-infected individuals with detectable plasma virus should receive treatment with recommended initial regimens consisting of an InSTI plus 2 NRTIs. Preexposure prophylaxis should be considered as part of an HIV prevention strategy for at-risk individuals. When used effectively, currently available ARVs can sustain HIV suppression and can prevent new HIV infection. With these treatment regimens, survival rates among HIV-infected adults who are retained in care can approach those of uninfected adults.