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.

Decreasing Incidence and Determinants of Bacterial Pneumonia in People With HIV: The Swiss HIV Cohort Study.

BACKGROUND: Bacterial pneumonia is a leading reason for hospitalization among people with HIV (PWH); however, evidence regarding its drivers in the era of potent antiretroviral therapy is limited. METHODS: We assessed risk factors for bacterial pneumonia in the Swiss HIV Cohort Study using marginal models. We further assessed the relationship between risk factors and changes in bacterial pneumonia incidence using mediation analysis. RESULTS: We included 12927 PWH with follow-ups between 2008 and 2018. These patients had 985 bacterial pneumonia events during a follow-up of 100779 person-years. Bacterial pneumonia incidence significantly decreased from 13.2 cases/1000 person-years in 2008 to 6.8 cases/1000 person-years in 2018. Older age, lower education level, intravenous drug use, smoking, lower CD4-cell count, higher HIV load, and prior pneumonia were significantly associated with higher bacterial pneumonia incidence. Notably, CD4 cell counts 350-499 cells/µL were significantly associated with an increased risk compared to CD4 ≥ 500 cells/µL (adjusted hazard ratio, 1.39; 95% confidence interval, 1.01-1.89). Decreasing incidence over the last decade can be explained by increased CD4-cell counts and viral suppression and decreased smoking frequency. CONCLUSIONS: Improvements in cascade of care of HIV and decrease in smoking may have mediated a substantial decrease in bacterial pneumonia incidence.

Cohort-Derived Machine Learning Models for Individual Prediction of Chronic Kidney Disease in People Living With Human Immunodeficiency Virus: A Prospective Multicenter Cohort Study.

BACKGROUND: It is unclear whether data-driven machine learning models, which are trained on large epidemiological cohorts, may improve prediction of comorbidities in people living with human immunodeficiency virus (HIV). METHODS: In this proof-of-concept study, we included people living with HIV in the prospective Swiss HIV Cohort Study with a first estimated glomerular filtration rate (eGFR) >60 mL/minute/1.73 m2 after 1 January 2002. Our primary outcome was chronic kidney disease (CKD)-defined as confirmed decrease in eGFR ≤60 mL/minute/1.73 m2 over 3 months apart. We split the cohort data into a training set (80%), validation set (10%), and test set (10%), stratified for CKD status and follow-up length. RESULTS: Of 12 761 eligible individuals (median baseline eGFR, 103 mL/minute/1.73 m2), 1192 (9%) developed a CKD after a median of 8 years. We used 64 static and 502 time-changing variables: Across prediction horizons and algorithms and in contrast to expert-based standard models, most machine learning models achieved state-of-the-art predictive performances with areas under the receiver operating characteristic curve and precision recall curve ranging from 0.926 to 0.996 and from 0.631 to 0.956, respectively. CONCLUSIONS: In people living with HIV, we observed state-of-the-art performances in forecasting individual CKD onsets with different machine learning algorithms.

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.

Predictors of Virological Failure and Time to Viral Suppression of First-Line Integrase Inhibitor-Based Antiretroviral Treatment.

BACKGROUND: Integrase strand transfer inhibitors (InSTIs) are recommended for first-line treatment of persons with human immunodeficiency virus (HIV). We identified risk factors, including baseline minor InSTI resistance mutations, for treatment failure of InSTI-based regimens. METHODS: We studied time-to-treatment failure and time to viral suppression among 1419 drug-naive patients in the Swiss HIV Cohort Study. We performed Cox regression models adjusted for demographic factors, baseline HIV RNA/CD4 cell counts, AIDS-defining events, and the type of InSTI. In 646 patients with a baseline genotypic resistance test of the integrase, we studied the impact of minor integrase resistance mutations. RESULTS: We observed 121 virological failures during 18 447 person-years of follow-up. A baseline viral load ≥100 000 copies/mL (multivariable hazard ratio [mHR], 2.2; 95% confidence interval [CI], 1.3-3.6) and an AIDS-defining event (mHR, 1.8; 95% CI. 1.1-3.0) were associated with treatment failure. CD4 counts between 200 and 500 cells/µL (mHR, 0.5; 95% CI, .3-.8) and >500 cells/µL (mHR, 0.4; 95% CI, .2-.7) were protective. Time to suppression was shorter in lower viral load strata (mHR, 0.7; 95% CI, .6-.8) and in dolutegravir-based therapy (mHR, 1.2; 95% CI, 1.0-1.4). Minor resistance mutations were found at baseline in 104 of 646 (16%) patients with no effect on treatment outcome. CONCLUSIONS: Factors associated with treatment failure on InSTI-based first-line regimen remained similar to those of older treatments, in particular high viral load and low CD4 counts.

Prevalence of Potential Drug-Drug Interactions in Patients of the Swiss HIV Cohort Study in the Era of HIV Integrase Inhibitors.

BACKGROUND: Prevalence of potential drug-drug interactions (PDDIs) between antiretroviral drugs (ARVs) and co-medications was high in 2008 in a Swiss HIV Cohort Study (SHCS) survey. We reassessed the prevalence of PDDIs in the era of human immunodeficiency virus (HIV) integrase inhibitors (INIs), characterized by more favorable interaction profiles. METHODS: The prevalence of PDDIs in treated HIV-positive individuals was assessed for the period 01-12/2018 by linkage of the Liverpool HIV drug interactions and SHCS databases. PDDIs were categorized as harmful (red flagged), of potential clinical relevance (amber flagged), or of weak clinical significance (yellow flagged). RESULTS: In 9298 included individuals, median age was 51 years (IQR, 43-58), and 72% were males. Individuals received unboosted INIs (40%), boosted ARVs (30%), and nonnucleoside reverse transcriptase inhibitor (NNRTIs) (32%)-based regimens. In the entire cohort, 68% received ≥1 co-medication, 14% had polypharmacy (≥5 co-medications) and 29% had ≥1 PDDI. Among individuals with co-medication, the prevalence of combined amber and yellow PDDIs was 43% (33% amber-mostly with cardiovascular drugs-and 20% yellow-flagged PDDIs) compared to 59% in 2008. Two percent had red-flagged PDDIs (mostly with corticosteroids), the same as in the 2008 survey. Compared with 2008, fewer individuals received boosted ARVs (-24%) and NNRTIs (-13%) but the use of co-medications was higher. CONCLUSIONS: Prevalence of PDDIs was lower with more widespread use of INIs in 2018 than in 2008. Continued use of boosted regimens and increasing needs for co-medications in this aging population impeded lower rates of PDDIs.

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.

Antibodies against HPV16E6 oncoprotein in the Swiss HIV cohort study: Kinetics and anal cancer risk prediction.

Our aim was to describe HPV16E6 antibody kinetics prior to anal cancer in people living with HIV/AIDS (PLWHA) and evaluate the possible contribution of HPV16E6 serology to anal cancer risk prediction. For 91 persons diagnosed with anal cancer in the Swiss HIV Cohort Study (1989-2017), serial serum/plasma samples were tested for HPV16E6 antibodies using multiplex serology, supplemented with samples from 1,356 participants without anal cancer. Anal cancer incidence was estimated for PLWHA from 40 years-old in the cART era, stratified by HPV16E6 serostatus. HPV16E6 seroprevalence was 23.3% in samples <2 years prior to anal cancer diagnosis and decreased with increasing time prior to cancer: 16.7% at 2-4 years, 4.4% at 5-9, and 7.0% at ≥10 years. Of 25 individuals with anal cancer who were HPV16E6-seropositive at any time during follow-up, the majority (n = 18) remained seropositive in all samples after seroconversion, whereas for seven cases, seropositivity was transitory. Among individuals with anal cancer, HPV16E6 seroprevalence was marginally higher in women vs. men who have sex with men (adjusted OR = 4.3, 95% CI: 1.1, 17.2) and in older participants (adjusted OR = 6.2, 95% CI: 1.1, 34.8 for cases diagnosed at ≥55 vs. <45 years). Anal cancer incidence was 402/100,000 person-years in HPV16E6-positive vs. 82/100,000 in HPV16E6-negative PLWHA (incidence rate ratio = 4.9, 95% CI: 1.3, 13.1). In conclusion, HPV16E6 serology, despite its low sensitivity, allows characterization of a group of individuals with very high anal cancer incidence and may have a place in secondary prevention in groups at high risk for anal cancer such as PLWHA.

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.

Inadequate Perioperative Prophylaxis and Postsurgical Complications After Graft Implantation Are Important Risk Factors for Subsequent Vascular Graft Infections: Prospective Results From the Vascular Graft Infection Cohort Study.

BACKGROUND: Reconstructive vascular surgery has become increasingly common. Vascular graft infections (VGIs) are serious complications, leading to increased morbidity and mortality. Previously described risk factors for VGIs include groin incisions, wound infections, and comorbidities. We aimed to identify modifiable predictors for VGIs as targets for infection prevention strategies. METHODS: Participants of the prospective Vascular Graft Infection Cohort (VASGRA) with surgery between 2013 and 2017 were included. The observation time was calculated from surgery until a confirmed VGI or the last follow-up. Variables were assessed by infection status, using non-parametric tests. Univariable and multivariable Cox proportional hazard regression models, adjusted for demographic factors, were applied to assess risk factors for a VGI. RESULTS: A total of 438 predominantly male (83.1%) patients with a median age of 71 years (interquartile range [IQR] 63 - 76) contributed to 554 person years of follow-up. Thereof, 39 (8.9%) developed a VGI, amounting to an incidence rate of 7.0/100 person years. We found incisional surgical site infections (adjusted hazard ratio [aHR] 10.09, 95% CI 2.88 - 35.34); hemorrhage (aHR 4.92, 1.28-18.94); renal insufficiency (aHR 4.85, 1.20 - 19.61); inadequate perioperative prophylaxis in patients with an established antibiotic treatment, compared to the additional application of perioperative prophylaxis (aHR 2.87, 95% CI 1.17 - 7.05); and procedure time increases of 1-hour intervals (aHR 1.22, 95% CI 1.08 - 1.39) to be risk factors for VGIs. CONCLUSIONS: We identified procedure time; inadequate perioperative prophylaxis, especially among patients with an established antibiotic treatment; and several postsurgical infectious and non-infectious complications as modifiable, predictive factors for VGIs and, therefore, as keys to improved surveillance programs and prevention strategies. CLINICAL TRIALS REGISTRATION: NCT01821664.

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.

No Effect of Pegylated Interferon-α on Total HIV-1 DNA Load in HIV-1/HCV Coinfected Patients.

Pegylated interferon-alpha (pIFN-α) is suggested to lower human immunodeficiency virus type-1 (HIV-1) DNA load in antiretroviral therapy (ART)-treated patients. We studied kinetics of HIV-1 DNA levels in 40 HIV-1/hepatitis C virus (HCV) coinfected patients, treated with pIFN-α for HCV and categorized into 3 groups according to start of ART: chronic HIV-1 infection (n = 22), acute HIV-1 infection (n = 8), no-ART (n = 10). Total HIV-1 DNA levels in 247 peripheral blood mononuclear cell samples were stable before, during, and after pIFN-α treatment in all groups. Our results question the benefit of pIFN-α as an immunotherapeutic agent for reducing the HIV-1 reservoir.

High Rates of Subsequent Asymptomatic Sexually Transmitted Infections and Risky Sexual Behavior in Patients Initially Presenting With Primary Human Immunodeficiency Virus-1 Infection.

Background: Knowledge of the risk factors of individuals with an asymptomatic sexually transmitted infection (STI) is essential for implementation of targeted STI screening strategies. Methods: Between June 2015 and January 2017, an STI screening was offered to all participants in the Zurich Primary human immunodeficiency virus (HIV)-1 Infection study. Patients were tested for gonorrhea, chlamydia, syphilis, and hepatitis C virus (HCV). Results: Of 214 participants, 174 (81%) were screened at least once. Most patients were men who have sex with men (MSM) (87.4%). Presenting with a primary HIV infection was associated with higher odds for later risky sexual behavior, as compared with presenting in the chronic phase (odds ratio [OR], 5.58; 95% confidence interval [CI], 3.68-8.8). In total, 79 STIs were detected, reflecting a high period prevalence of 33.3% (58 of 174 patients). Sixty-six percent of patients (52 of 79) were asymptomatic. Most common STIs were chlamydia (50.6%; 40 of 79 patients), gonorrhea (25.3%; 20 of 79), and syphilis (19%; 15 of 79). In a multivariable model, engaging in insertive (OR, 6.48; 95% CI, 1.14-36.76) or both insertive and receptive (4.61; 1.01-20.96) anal intercourse, STI symptoms (3.4; 1.68-6.89), and condomless sex (2.06; 1.14-3.74) were positively correlated with a positive screening result. The hazard of an incident STI increased with the presence of STI symptoms (hazard ratio, 3.03; 95% CI, 1.17-7.84) and any recent drug use (2.63; 1-6.9). Conclusions: A trimonthly STI screening including asymptomatic individuals should be considered in this population, particularly in MSM who report sexual risk behavior. Clinical Trial Registration: NCT 00537966.

Long-term leukocyte reconstitution in NSG mice transplanted with human cord blood hematopoietic stem and progenitor cells.

BACKGROUND: Humanized mice (hu mice) are based on the transplantation of hematopoietic stem and progenitor cells into immunodeficient mice and have become important pre-clinical models for biomedical research. However, data about their hematopoiesis over time are scarce. We therefore characterized leukocyte reconstitution in NSG mice, which were sublethally irradiated and transplanted with human cord blood-derived CD34+ cells at newborn age, longitudinally in peripheral blood and, for more detailed analyses, cross-sectionally in peripheral blood, spleen and bone marrow at different time points. RESULTS: Human cell chimerism and absolute human cell count decreased between week 16 and 24 in the peripheral blood of hu mice, but were stable thereafter as assessed up to 32 weeks. Human cell chimerism in spleen and bone marrow was maintained over time. Notably, human cell chimerism in peripheral blood and spleen as well as bone marrow positively correlated with each other. Percentage of B cells decreased between week 16 and 24, whereas percentage of T cells increased; subsequently, they levelled off with T cells clearly predominating at week 32. Natural killer cells, monocytes and plasmacytoid dendritic cells (DCs) as well as CD1c + and CD141+ myeloid DCs were all present in hu mice. Proliferative responses of splenic T cells to stimulation were preserved over time. Importantly, the percentage of more primitive hematopoietic stem cells (HSCs) in bone marrow was maintained over time. CONCLUSIONS: Overall, leukocyte reconstitution was maintained up to 32 weeks post-transplantation in our hu NSG model, possibly explained by the maintenance of HSCs in the bone marrow. Notably, we observed great variation in multi-lineage hematopoietic reconstitution in hu mice that needs to be taken into account for the experimental design with hu mice.

Persistence of transmitted HIV-1 drug resistance mutations associated with fitness costs and viral genetic backgrounds.

Transmission of drug-resistant pathogens presents an almost-universal challenge for fighting infectious diseases. Transmitted drug resistance mutations (TDRM) can persist in the absence of drugs for considerable time. It is generally believed that differential TDRM-persistence is caused, at least partially, by variations in TDRM-fitness-costs. However, in vivo epidemiological evidence for the impact of fitness costs on TDRM-persistence is rare. Here, we studied the persistence of TDRM in HIV-1 using longitudinally-sampled nucleotide sequences from the Swiss-HIV-Cohort-Study (SHCS). All treatment-naïve individuals with TDRM at baseline were included. Persistence of TDRM was quantified via reversion rates (RR) determined with interval-censored survival models. Fitness costs of TDRM were estimated in the genetic background in which they occurred using a previously published and validated machine-learning algorithm (based on in vitro replicative capacities) and were included in the survival models as explanatory variables. In 857 sequential samples from 168 treatment-naïve patients, 17 TDRM were analyzed. RR varied substantially and ranged from 174.0/100-person-years;CI=[51.4, 588.8] (for 184V) to 2.7/100-person-years;[0.7, 10.9] (for 215D). RR increased significantly with fitness cost (increase by 1.6[1.3,2.0] per standard deviation of fitness costs). When subdividing fitness costs into the average fitness cost of a given mutation and the deviation from the average fitness cost of a mutation in a given genetic background, we found that both components were significantly associated with reversion-rates. Our results show that the substantial variations of TDRM persistence in the absence of drugs are associated with fitness-cost differences both among mutations and among different genetic backgrounds for the same mutation.

Incidence of hepatitis C in HIV positive and negative men who have sex with men 2000-2016: a systematic review and meta-analysis.

BACKGROUND: There is a need for systematic reviews and meta-analyses to synthesize the epidemiology, and the riskfactors for hepatitis C virus (HCV) among HIV-coinfected and HIV negative men who have sex with men (MSM). METHODS: A meta-analysis of 28 studies was carried out by pooling HCV incidence data of HIV-coinfected and HIV negative MSM. Differences in incidence outcome depending on the prospective or retrospective nature of the individual studies were investigated. RESULTS: The pooled incidence of HCV in MSM was 6.3 per 1000 person-years (95% CI 5.0-7.5). The overall estimated incidence was 19-fold higher in HIV positive compared to HIV negative MSM living in resource-rich countries. This result was confirmed when the analysis was restricted to high-quality studies. Factors associated with an increased risk for incident HCV included behavioural factors (sexual risk behaviour and recreational drug use) as well as biological characteristics (HIV coinfection and a recent history of syphilis). CONCLUSION: In conclusion, incident HCV predominantly affects HIV positive MSM. The incidence rate varied largely between studies, factors such as study design might play an important role.

Early virological failure and HIV drug resistance in Ugandan adults co-infected with tuberculosis.

PURPOSE: This cross-sectional study took place in the integrated tuberculosis (TB) clinic of a large outpatient clinic for HIV-infected patients in Kampala, Uganda. The purpose of this study was to describe the proportion of TB/HIV co-infected adults with virological failure, type and frequency of HIV drug resistance-associated mutations, and the proportion of patients with suboptimal efavirenz levels. METHODS: HIV-1 plasma viral loads, CD4 cell count measurements, and efavirenz serum concentrations were done in TB/HIV co-infected adults. Genotypic resistance testing was performed in case of confirmed virological failure. RESULTS: After a median time on ART of 6 months, virological failure was found in 22/152 patients (14.5%). Of 147 participants with available efavirenz serum concentration, 26 (17.6%) had at least one value below the reference range, including 20/21 (95.2%) patients with confirmed virological failure. Genotypic resistance testing was available for 16/22 (72.7%) patients, of which 15 (93.8%) had at least one major mutation, most commonly M184V (81.2%) and K103NS (68.8%). CONCLUSION: We found a high proportion of TB/HIV co-infected patients with virological failure, the majority of which had developed relevant resistance-mutations after a median time on anti-retroviral treatment (ART) of 6 months. Virological monitoring should be prioritized in TB/HIV co-infected patients in resource-limited settings.

Dually Active HIV/HBV Antiretrovirals as Protection Against Incident Hepatitis B Infections: Potential for Prophylaxis.

BACKGROUND: Hepatitis B virus (HBV) has a detrimental effect on human immunodeficiency virus (HIV) natural course, and HBV vaccination is less effective in the HIV infected. We examine the protective effect of dually active antiretroviral therapy (DAART) for HIV/HBV (tenofovir, lamivudine, and emtricitabine) in a large cohort encompassing heterosexuals, men who have sex with men, and intravenous drug users who are HIV infected yet susceptible to HBV, with comprehensive follow-up data about risky behavior and immunological profiles. METHODS: We defined an incident HBV infection as the presence of any of HBV serological markers (hepatitis B surface antigen, anti-hepatitis B core antibodies, or HBV DNA) after a negative baseline test result for anti-hepatitis B core antibodies. Patients with positive anti-hepatitis B surface antigen serology were excluded. Cox proportional hazards models were used, with an incident case of HBV infection as the outcome variable. RESULTS: We analyzed 1716 eligible patients from the Swiss HIV Cohort Study with 177 incident HBV cases. DAART was negatively associated with incident HBV infection (hazard ratio [HR], 0.4; 95% confidence interval [CI], .2-.6). This protective association was robust to adjustment (HR, 0.3; 95% CI, .2-.5) for condomless sex, square-root-transformed CD4 cell count, drug use, and patient demographics. Condomless sex (HR, 1.9; 95% CI, 1.4-2.6), being a man who has sex with men (2.7; 1.7-4.2), and being an intravenous drug user (3.8; 2.4-6.1) were all associated with a higher hazard of contracting HBV. CONCLUSIONS: Our study suggests that DAART, independently of CD4 cell count and risky behavior, has a potentially strong public health impact, including pre-exposure prophylaxis of HBV coinfection in the HIV infected.

Successful Prevention of Transmission of Integrase Resistance in the Swiss HIV Cohort Study.

The prevalence of integrase strand transfer inhibitor (INSTI)-transmitted drug resistance (TDR) may increase with the increasing use of INSTIs. We analyzed the prevalence of INSTI TDR in the Swiss HIV Cohort Study (2008-2014). In 1 of 1316 drug-naive samples (0.1%), a major INSTI TDR mutation was detected. Prevalence was stable, although INSTIs were increasingly used. We showed that this is in contrast to the introduction of previous drug classes, in which more treatment failures with resistant strains occurred and TDR was observed more rapidly. We demonstrated on a population-level that it is possible to avoid TDR to a new drug class for years.

Emergence of Acquired HIV-1 Drug Resistance Almost Stopped in Switzerland: A 15-Year Prospective Cohort Analysis.

BACKGROUND: Drug resistance is a major barrier to successful antiretroviral treatment (ART). Therefore, it is important to monitor time trends at a population level. METHODS: We included 11 084 ART-experienced patients from the Swiss HIV Cohort Study (SHCS) between 1999 and 2013. The SHCS is highly representative and includes 72% of patients receiving ART in Switzerland. Drug resistance was defined as the presence of ≥1 major mutation in a genotypic resistance test. To estimate the prevalence of drug resistance, data for patients with no resistance test was imputed based on the patient's risk of harboring drug-resistant viruses. RESULTS: The emergence of new drug resistance mutations declined dramatically from 401 to 23 patients between 1999 and 2013. The upper estimated prevalence limit of drug resistance among ART-experienced patients decreased from 57.0% in 1999 to 37.1% in 2013. The prevalence of 3-class resistance decreased from 9.0% to 4.4% and was always <0.4% for patients who initiated ART after 2006. Most patients actively participating in the SHCS in 2013 with drug-resistant viruses initiated ART before 1999 (59.8%). Nevertheless, in 2013, 94.5% of patients who initiated ART before 1999 had good remaining treatment options based on Stanford algorithm. CONCLUSIONS: Human immunodeficiency virus type 1 drug resistance among ART-experienced patients in Switzerland is a well-controlled relic from the era before combination ART. Emergence of drug resistance can be virtually stopped with new potent therapies and close monitoring.