Tracing HIV-1 strains that imprint broadly neutralizing antibody responses.

Understanding the determinants of broadly neutralizing antibody (bNAb) evolution is crucial for the development of bNAb-based HIV vaccines1. Despite emerging information on cofactors that promote bNAb evolution in natural HIV-1 infections, in which the induction of bNAbs is genuinely rare2, information on the impact of the infecting virus strain on determining the breadth and specificity of the antibody responses to HIV-1 is lacking. Here we analyse the influence of viral antigens in shaping antibody responses in humans. We call the ability of a virus strain to induce similar antibody responses across different hosts its antibody-imprinting capacity, which from an evolutionary biology perspective corresponds to the viral heritability of the antibody responses. Analysis of 53 measured parameters of HIV-1-binding and neutralizing antibody responses in a cohort of 303 HIV-1 transmission pairs (individuals who harboured highly related HIV-1 strains and were putative direct transmission partners or members of an HIV-1 transmission chain) revealed that the effect of the infecting virus on the outcome of the bNAb response is moderate in magnitude but highly significant. We introduce the concept of bNAb-imprinting viruses and provide evidence for the existence of such viruses in a systematic screening of our cohort. The bNAb-imprinting capacity can be substantial, as indicated by a transmission pair with highly similar HIV-1 antibody responses and strong bNAb activity. Identification of viruses that have bNAb-imprinting capacities and their characterization may thus provide the potential to develop lead immunogens.

A Phylogeny-aware GWAS Framework to Correct for Heritable Pathogen Effects on Infectious Disease Traits.

Infectious diseases are particularly challenging for genome-wide association studies (GWAS) because genetic effects from two organisms (pathogen and host) can influence a trait. Traditional GWAS assume individual samples are independent observations. However, pathogen effects on a trait can be heritable from donor to recipient in transmission chains. Thus, residuals in GWAS association tests for host genetic effects may not be independent due to shared pathogen ancestry. We propose a new method to estimate and remove heritable pathogen effects on a trait based on the pathogen phylogeny prior to host GWAS, thus restoring independence of samples. In simulations, we show this additional step can increase GWAS power to detect truly associated host variants when pathogen effects are highly heritable, with strong phylogenetic correlations. We applied our framework to data from two different host-pathogen systems, HIV in humans and X. arboricola in A. thaliana. In both systems, the heritability and thus phylogenetic correlations turn out to be low enough such that qualitative results of GWAS do not change when accounting for the pathogen shared ancestry through a correction step. This means that previous GWAS results applied to these two systems should not be biased due to shared pathogen ancestry. In summary, our framework provides additional information on the evolutionary dynamics of traits in pathogen populations and may improve GWAS if pathogen effects are highly phylogenetically correlated amongst individuals in a cohort.

Dolutegravir in real life: Self-reported mental and physical health outcomes after transitioning from efavirenz- to dolutegravir-based antiretroviral therapy in a prospective cohort study in Lesotho.

INTRODUCTION: HIV programmes across many countries in Africa have recently transitioned people living with HIV from efavirenz (EFV)- to dolutegravir (DTG)-containing antiretroviral therapy (ART). As both drugs are associated with neuropsychiatric adverse effects, this study assessed the mental health and HIV/ART-associated symptoms of people living with HIV before and after transition to DTG. METHODS: The prospective DO-REAL cohort enrolled people starting DTG-based ART in Lesotho from February to December 2020. For this analysis within DO-REAL, we included adults changing from tenofovir disoproxil fumarate (TDF)/lamivudine (3TC)/EFV to TDF/3TC/DTG within first-line therapy. At transition and 16 weeks thereafter, participants completed the Patient Health Questionnaire-9 (PHQ-9; depression screening), the 12-item Short-Form Health Survey (SF-12; mental and physical health), and a modified HIV Symptom Index (mHSI; HIV/ART-related symptoms). We also assessed weight change. We used McNemar tests with Bonferroni corrections to assess binary outcomes. CLINICALTRIALS: gov: NCT04238767. RESULTS: Among 1228 participants, 1131 completed follow-up. Of these, 60.0% were female, the median age was 46 years (interquartile range [IQR] 38-55), and the median time taking ART was 5.7 years (IQR 3.5-8.9). No change was observed for weight or overall PHQ-9 or SF-12 outcomes. However, three mHSI items decreased at follow-up: 'feeling sad/down/depressed' (bothered 6.0% vs. 3.3% of participants at least 'a little' before vs. after transition; adjusted p = 0.048); 'feeling nervous/anxious' (7.4% vs. 3.4%; adjusted p = 0.0009); and 'nightmares, strange/vivid dreams' (6.3% vs. 3.5%; adjusted p = 0.027). Individual PHQ-9 or SF-12 items also improved. Being symptom free across all measures increased from 5.1% to 11.4% (p < 0.0001). CONCLUSIONS: We observed no negative impacts and potential moderate improvements with DTG, providing further support for the rollout of DTG.

Decentralization of viral load testing to improve HIV care and treatment cascade in rural Tanzania: observational study from the Kilombero and Ulanga Antiretroviral Cohort.

INTRODUCTION: Monitoring HIV viral load (HVL) in people living with HIV (PLHIV) on antiretroviral therapy (ART) is recommended by the World Health Organization. Implementation of HVL testing programs have been affected by logistic and organizational challenges. Here we describe the HVL monitoring cascade in a rural setting in Tanzania and compare turnaround times (TAT) between an on-site and a referral laboratory. METHODS: In a nested study of the prospective Kilombero and Ulanga Antiretroviral Cohort (KIULARCO) we included PLHIV aged ≥ 15 years, on ART for ≥ 6 months after implementation of routine HVL monitoring in 2017. We assessed proportions of PLHIV with a blood sample taken for HVL, whose results came back, and who were virally suppressed (HVL < 1000 copies/mL) or unsuppressed (HVL ≥ 1000 copies/mL). We described the proportion of PLHIV with unsuppressed HVL and adequate measures taken as per national guidelines and outcomes among those with low-level viremia (LLV; 100-999 copies/mL). We compare TAT between on-site and referral laboratories by Wilcoxon rank sum tests. RESULTS: From 2017 to 2020, among 4,454 PLHIV, 4,238 (95%) had a blood sample taken and 4,177 (99%) of those had a result. Of those, 3,683 (88%) were virally suppressed. In the 494 (12%) unsuppressed PLHIV, 425 (86%) had a follow-up HVL (102 (24%) within 4 months and 158 (37%) had virologic failure. Of these, 103 (65%) were already on second-line ART and 32/55 (58%) switched from first- to second-line ART after a median of 7.7 months (IQR 4.7-12.7). In the 371 (9%) PLHIV with LLV, 327 (88%) had a follow-up HVL. Of these, 267 (82%) resuppressed to < 100 copies/ml, 41 (13%) had persistent LLV and 19 (6%) had unsuppressed HVL. The median TAT for return of HVL results was 21 days (IQR 13-39) at the on-site versus 59 days (IQR 27-99) at the referral laboratory (p < 0.001) with PLHIV receiving the HVL results after a median of 91 days (IQR 36-94; similar for both laboratories). CONCLUSION: Robust HVL monitoring is achievable in remote resource-limited settings. More focus is needed on care models for PLHIV with high viral loads to timely address results from routine HVL monitoring.

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.

Viral suppression after transition from nonnucleoside reverse transcriptase inhibitor- to dolutegravir-based antiretroviral therapy: A prospective cohort study in Lesotho (DO-REAL study).

OBJECTIVES: Since 2018, the World Health Organization has recommended dolutegravir (DTG)-containing antiretroviral therapy (ART) for most people living with HIV. Country programmes across Africa have subsequently transitioned from other, mostly nonnucleoside reverse transcriptase inhibitor (NNRTI)-based ART to DTG-based ART. This study aims to assess the virological impact of programmatic transitioning to DTG-based ART in Lesotho. METHODS: The prospective Dolutegravir in Real-Life in Lesotho (DO-REAL) cohort enrols people living with HIV initiating or transitioning to DTG-based ART in Lesotho. Here, we present data from participants who transitioned from NNRTI- to DTG-based ART between February and December 2020. Blood samples collected at transition and at 16 weeks' follow-up (window 8-32 weeks) were used for viral load (VL) and resistance testing. RESULTS: Among 1347 participants, follow-up data was available for 1225. The majority (60%) were female, median age at transition was 47 years [interquartile range (IQR): 38-56], and median (IQR) time since ART initiation was 5.9 (3.5-9.0) years. Among those with complete VL data, the rate of viral suppression to < 100 copies/mL was 1093/1116 (98%) before, 1073/1116 (96%) at, and 1098/1116 (98%) after transition. Even among those with a VL ≥ 100 copies/mL at transition, 42/44 (95%) achieved suppression to < 100 copies/mL at follow-up. Seven participants had a VL ≥ 1000 copies/mL at follow-up and did not harbour any integrase mutations associated with resistance to DTG. CONCLUSIONS: The high levels of viral suppression observed are encouraging regarding virological outcomes upon programmatic transitioning from NNRTI- to DTG-based ART.

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.

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.

Offering ART refill through community health workers versus clinic-based follow-up after home-based same-day ART initiation in rural Lesotho: The VIBRA cluster-randomized clinical trial.

BACKGROUND: Community-based antiretroviral therapy (ART) dispensing by lay workers is an important differentiated service delivery model in sub-Sahara Africa. However, patients new in care are generally excluded from such models. Home-based same-day ART initiation is becoming widespread practice, but linkage to the clinic is challenging. The pragmatic VIBRA (Village-Based Refill of ART) trial compared ART refill by existing lay village health workers (VHWs) versus clinic-based refill after home-based same-day ART initiation. METHODS AND FINDINGS: The VIBRA trial is a cluster-randomized open-label clinical superiority trial conducted in 249 rural villages in the catchment areas of 20 health facilities in 2 districts (Butha-Buthe and Mokhotlong) in Lesotho. In villages (clusters) randomized to the intervention arm, individuals found to be HIV-positive during a door-to-door HIV testing campaign were offered same-day ART initiation with the option of refill by VHWs. The trained VHWs dispensed drugs and scheduled clinic visits for viral load measurement at 6 and 12 months. In villages randomized to the control arm, participants were offered same-day ART initiation with clinic-based ART refill. The primary outcome was 12-month viral suppression. Secondary endpoints included linkage and 12-month engagement in care. Analyses were intention-to-treat. The trial was registered on ClinicalTrials.gov (NCT03630549). From 16 August 2018 until 28 May 2019, 118 individuals from 108 households in 57 clusters in the intervention arm, and 139 individuals from 130 households in 60 clusters in the control arm, were enrolled (150 [58%] female; median age 36 years [interquartile range 30-48]; 200 [78%] newly diagnosed). In the intervention arm, 48/118 (41%) opted for VHW refill. At 12 months, 46/118 (39%) participants in the intervention arm and 64/139 (46%) in the control arm achieved viral suppression (adjusted risk difference -0.07 [95% CI -0.20 to 0.06]; p = 0.256). Arms were similar in linkage (adjusted risk difference 0.03 [-0.10 to 0.16]; p = 0.630), but engagement in care was non-significantly lower in the intervention arm (adjusted risk difference -0.12 [-0.23 to 0.003]; p = 0.058). Seven and 0 deaths occurred in the intervention and control arm, respectively. Of the intervention participants who did not opt for drug refill from the VHW at enrollment, 41/70 (59%) mentioned trust or conflict issues as the primary reason. Study limitations include a rather small sample size, 9% missing viral load measurements in the primary endpoint window, the low uptake of the VHW refill option in the intervention arm, and substantial migration among the study population. CONCLUSIONS: The offer of village-based ART refill after same-day initiation led to similar outcomes as clinic-based refill. The intervention did not amplify the effect of home-based same-day ART initiation alone. The findings raise concerns about acceptance and safety of ART delivered by lay health workers after initiation in the community. TRIAL REGISTRATION: Registered with Clinicaltrials.gov (NCT03630549).

Extensive drug resistance during low-level HIV viraemia while taking NNRTI-based ART supports lowering the viral load threshold for regimen switch in resource-limited settings: a pre-planned analysis from the SESOTHO trial.

OBJECTIVES: WHO guidelines on ART define the HIV-1 viral load (VL) threshold for treatment failure at 1000 copies/mL. The Switch Either near Suppression Or THOusand (SESOTHO) trial, conducted in Lesotho from 2017 to 2020, found that patients with persistent viraemia below this threshold (100-999 copies/mL) benefit from switching to second-line ART. This pre-planned nested study assesses the prevalence of resistance-associated mutations (RAMs) in SESOTHO trial participants. METHODS: The SESOTHO trial [registered at ClinicalTrials.gov (NCT03088241)] enrolled 80 persons taking NNRTI-based first-line ART with low-level HIV-1 viraemia (100-999 copies/mL) and randomized them (1:1) to switch to a PI-based second-line regimen (switch) or continue on first-line therapy (control). We sequenced relevant regions of the viral pol gene using plasma samples obtained at enrolment and 36 weeks. RAMs were classified with the Stanford HIV Drug Resistance Database. RESULTS: Sequencing data were obtained for 37/80 (46%) participants at baseline and 26/48 (54%) participants without viral suppression to <50 copies/mL at 36 weeks (21 control participants and 5 switch participants). At baseline, 31/37 (84%) participants harboured high-level resistance to at least two drugs of their current regimen. At 36 weeks, 17/21 (81%) control participants harboured resistance to at least two drugs of their current regimen, while no PI-associated resistance was detected in the 5 switch participants with ongoing viraemia. CONCLUSIONS: Among persons with low-level viraemia while taking NNRTI-based first-line ART enrolled in the SESOTHO trial, the majority harboured HIV-1 with RAMs that necessitate ART modification. These findings support lowering the VL threshold triggering a switch to second-line ART in future WHO guidelines.

Engagement in Care, Viral Suppression, Drug Resistance, and Reasons for Nonengagement After Home-Based Same-Day Antiretroviral Therapy Initiation in Lesotho: A Two-Year Follow-up of the CASCADE Trial.

BACKGROUND: The CASCADE trial showed that compared with usual care (UC), offering same-day (SD) antiretroviral therapy (ART) during home-based human immunodeficiency virus testing improved engagement in care and viral suppression 12 months after diagnosis. However, questions remain regarding long-term outcomes and the risk of propagating drug resistance. METHODS: After completion of the primary endpoint at 12 months, participants not in care in both arms were traced and encouraged to access care. At 24 months, the following outcomes were assessed in both arms: engagement in care, viral suppression, and reasons for nonengagement. Furthermore, we explored the acquisition of drug resistance mutations (DRMs) among SD arm nonlinkers. RESULTS: At 24 months, 64% (88/137) in the SD arm vs 59% (81/137) in the UC arm were in care (absolute difference [AD], 5%; 95% confidence interval [CI], -6 to16; P = .38) and 57% (78/137) vs 54% (74/137) had documented viral suppression (AD, 3%; 95% CI, -9 to 15; P = .28). Among 36 participants alive and not in care at 24 months with ascertained status, the majority rejected contact with the health system or were unwilling to take ART. Among 8 interviewed SD arm nonlinkers, 6 had not initiated ART upon enrollment, and no acquired DRMs were detected. Two had taken the initial 30-day ART supply and acquired DRMs. CONCLUSIONS: SD ART resulted in higher rates of engagement in care and viral suppression at 12 months but not at 24 months. Leveling off between both arms was driven by linkage beyond 12 months in the UC arm. We did not observe compensatory long-term disengagement in the SD arm. These long-term results endorse SD ART initiation policies. CLINICAL TRIALS REGISTRATION: NCT02692027.

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.

Switch to second-line versus continued first-line antiretroviral therapy for patients with low-level HIV-1 viremia: An open-label randomized controlled trial in Lesotho.

BACKGROUND: Current World Health Organization (WHO) antiretroviral therapy (ART) guidelines define virologic failure as two consecutive viral load (VL) measurements ≥1,000 copies/mL, triggering empiric switch to next-line ART. This trial assessed if patients with sustained low-level HIV-1 viremia on first-line ART benefit from a switch to second-line treatment. METHODS AND FINDINGS: This multicenter, parallel-group, open-label, superiority, randomized controlled trial enrolled patients on first-line ART containing non-nucleoside reverse transcriptase inhibitors (NNRTI) with two consecutive VLs ≥100 copies/mL, with the second VL between 100-999 copies/mL, from eight clinics in Lesotho. Consenting participants were randomly assigned (1:1), stratified by facility, demographic group, and baseline VL, to either switch to second-line ART (switch group) or continued first-line ART (control group; WHO guidelines). The primary endpoint was viral suppression (<50 copies/mL) at 36 weeks. Analyses were by intention to treat, using logistic regression models, adjusted for demographic group and baseline VL. Between August 1, 2017, and August 7, 2019, 137 individuals were screened, of whom 80 were eligible and randomly assigned to switch (n = 40) or control group (n = 40). The majority of participants were female (54 [68%]) with a median age of 42 y (interquartile range [IQR] 35-51), taking tenofovir disoproxil fumarate/lamivudine/efavirenz (49 [61%]) and on ART for a median of 5.9 y (IQR 3.3-8.6). At 36 weeks, 22/40 (55%) participants in the switch versus 10/40 (25%) in the control group achieved viral suppression (adjusted difference 29%, 95% CI 8%-50%, p = 0.009). The switch group had significantly higher probability of viral suppression across different VL thresholds (<20, <100, <200, <400, and <600 copies/mL) but not for <1,000 copies/mL. Thirty-four (85%) participants in switch group and 21 (53%) in control group experienced at least one adverse event (AE) (p = 0.002). No hospitalization or death or other serious adverse events were observed. Study limitations include a follow-up period too short to observe differences in clinical outcomes, missing values in CD4 cell counts due to national stockout of reagents during the study, and limited generalizability of findings to other than NNRTI-based first-line ART regimens. CONCLUSIONS: In this study, switching to second-line ART among patients with sustained low-level HIV-1 viremia resulted in a higher proportion of participants with viral suppression. These results endorse lowering the threshold for virologic failure in future WHO guidelines. TRIAL REGISTRATION: The trial is registered at ClinicalTrials.gov, NCT03088241.

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.

Low rates of active hepatitis B and C infections among adults and children living with HIV and taking antiretroviral therapy: A multicenter screening study in Lesotho.

Lesotho presents the second-highest adult human immunodeficiency virus (HIV) prevalence globally. Among people living with HIV, data on hepatitis B virus (HBV) or hepatitis C virus (HCV) coinfection are limited. We report HBV and HCV coinfection data from a multicentre cross-sectional study among adult and pediatric patients taking antiretroviral therapy in 10 health facilities in Lesotho. Among 1318 adults screened (68% female; median age, 44 years), 262 (20%) had immunologically controlled HBV infection, 99 (7.6%) tested anti-HBs positive and anti-HBc negative, indicating vaccination, and 57 (4.3%) had chronic HBV infection. Among the patients with chronic HBV infection, 15 tested hepatitis B envelope antigen (HBeAg) positive and eight had detectable HBV viremia (median, 2 477 400 copies/mL; interquartile range, 205-34 400 000) with a mean aspartate aminotransferase-to-platelet ratio index of 0.48 (SD, 0.40). Prevalence of HCV coinfection was 1.7% (22 of 1318), and only one patient had detectable HCV viremia. Among 162 pediatric patients screened, three (1.9%) had chronic HBV infection, whereby two also tested HBeAg-positive, and one had detectable HBV viral load (210 copies/mL). Six of 162 (3.7%) had anti-HCV antibodies, all with undetectable HCV viral loads. Overall prevalence of chronic HBV/HIV and HCV/HIV coinfection among adults and children was relatively low, comparable to earlier reports from the same region. But prevalence of immunologically controlled HBV infection among adults was high. Of those patients with chronic HBV infection, a minority had detectable HBV-DNA.

Genotype-Informed Versus Empiric Management Of VirEmia (GIVE MOVE): study protocol of an open-label randomised clinical trial in children and adolescents living with HIV in Lesotho and Tanzania.

BACKGROUND: Globally, the majority of people living with HIV have no or only limited access to HIV drug resistance testing to guide the selection of antiretroviral drugs. This is of particular concern for children and adolescents, who experience high rates of treatment failure. The GIVE MOVE trial assesses the clinical impact and cost-effectiveness of routinely providing genotypic resistance testing (GRT) to children and adolescents living with HIV who have an unsuppressed viral load (VL) while taking antiretroviral therapy (ART). METHODS: GIVE MOVE is an open-label randomised clinical trial enrolling children and adolescents (≥6 months to <19 years) living with HIV with a VL ≥400 copies/mL (c/mL) while taking first-line ART. Recruitment takes place at sites in Lesotho and Tanzania. Participants are randomised in a 1:1 allocation to a control arm receiving the standard of care (3 sessions of enhanced adherence counselling, a follow-up VL test, continuation of the same regimen upon viral resuppression or empiric selection of a new regimen upon sustained elevated viremia) and an intervention arm (GRT to inform onward treatment). The composite primary endpoint is the occurrence of any one or more of the following events during the 36 weeks of follow-up period: i) death due to any cause; ii) HIV- or ART-related hospital admission of ≥24 h duration; iii) new clinical World Health Organisation stage 4 event (excluding lymph node tuberculosis, stunting, oral or genital herpes simplex infection and oesophageal candidiasis); and iv) no documented VL <50 c/mL at 36 weeks follow-up. Secondary and exploratory endpoints assess additional health-related outcomes, and a nested study will assess the cost-effectiveness of the intervention. Enrolment of a total of 276 participants is planned, with an interim analysis scheduled after the first 138 participants have completed follow-up. DISCUSSION: This randomised clinical trial will assess if the availability of resistance testing improves clinical outcomes in children and adolescents with elevated viremia while taking ART. TRIAL REGISTRATION: This trial is registered with ClinicalTrials.gov ( NCT04233242 ; registered 18.01.2020). More information: www.givemove.org .

A Systematic Phylogenetic Approach to Study the Interaction of HIV-1 With Coinfections, Noncommunicable Diseases, and Opportunistic Diseases.

To systematically test whether coinfections spread along the HIV-1 transmission network and whether similarities in HIV-1 genomes predict AIDS-defining illnesses and comorbidities, we analyzed the distribution of these variables on the HIV phylogeny of the densely sampled Swiss HIV Cohort Study. By combining different statistical methods, we could detect, quantify, and explain the clustering of diseases. Infectious conditions such as hepatitis C, but also Kaposi sarcoma, clustered significantly, suggesting transmission of these infections along the HIV-1 transmission network. The clustering of patients with neurocognitive complaints could not be completely explained by the clustering of patients with similar demographic risk factors, which suggests a potential impact of viral genetics. In summary, the consistent and robust signal for coinfections and comorbidities highlights the strong interaction of HIV-1 and other infections and shows the potential of combining phylogenetic methods to identify disease traits that are likely to be related to virus genetic factors.

Viral Diversity Based on Next-Generation Sequencing of HIV-1 Provides Precise Estimates of Infection Recency and Time Since Infection.

BACKGROUND: Human immunodeficiency virus type 1 (HIV-1) genetic diversity increases over the course of infection and can be used to infer the time since infection and, consequently, infection recency, which are crucial for HIV-1 surveillance and the understanding of viral pathogenesis. METHODS: We considered 313 HIV-infected individuals for whom reliable estimates of infection dates and next-generation sequencing (NGS)-derived nucleotide frequency data were available. Fractions of ambiguous nucleotides, obtained by population sequencing, were available for 207 samples. We assessed whether the average pairwise diversity calculated using NGS sequences provided a more exact prediction of the time since infection and classification of infection recency (<1 year after infection), compared with the fraction of ambiguous nucleotides. RESULTS: NGS-derived average pairwise diversity classified an infection as recent with a sensitivity of 88% and a specificity of 85%. When considering only the 207 samples for which fractions of ambiguous nucleotides were available, the NGS-derived average pairwise diversity exhibited a higher sensitivity (90% vs 78%) and specificity (95% vs 67%) than the fraction of ambiguous nucleotides. Additionally, the average pairwise diversity could be used to estimate the time since infection with a mean absolute error of 0.84 years, compared with 1.03 years for the fraction of ambiguous nucleotides. CONCLUSIONS: Viral diversity based on NGS data is more precise than that based on population sequencing in its ability to predict infection recency and provides an estimated time since infection that has a mean absolute error of <1 year.

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.

Importance of routine viral load monitoring: higher levels of resistance at ART failure in Uganda and Lesotho compared with Switzerland.

Objectives: Emerging resistance to antiretroviral drugs may jeopardize the achievements of improved access to ART. We compared the prevalence of different resistance mutations in HIV-infected adults with virological failure in a cohort with regular routine viral load (VL) monitoring (Switzerland) and cohorts with limited access to VL testing (Uganda and Lesotho). Methods: We considered individuals who had genotypic resistance testing (GRT) upon virological failure (≥1000 copies/mL) and were on ART consisting of at least one NNRTI and two NRTIs. From Lesotho, individuals with two subsequent VLs ≥1000 copies/mL despite enhanced adherence counselling (n = 58) were included in the analysis. From Uganda, individuals with a single VL ≥1000 copies/mL (n = 120) were included in the analysis. From the Swiss HIV Cohort Study (SHCS), a population without history of monotherapy or dual therapy with the first GRT upon virological failure (n = 61) was selected. Results: We found that 50.8% of individuals in the SHCS, 72.5% in Uganda and 81.0% in Lesotho harboured HIV with high-level resistance to at least two drugs from their current regimen. Stanford resistance scores were higher in Uganda compared with Switzerland for all drugs used in first-line treatment except zidovudine and tenofovir (P < 0.01) and higher in Lesotho compared with Uganda for all drugs used in first-line treatment except zidovudine (P < 0.01). Conclusions: Frequent VL monitoring and possibly pretreatment GRT as done in the SHCS pays off by low levels of resistance even when treatment failure occurs. The high-level resistance patterns in Lesotho compared with Uganda could reflect a selection of strains with multiple resistance during enhanced adherence counselling.