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.

Time Trends in Causes of Death in People with HIV: Insights from the Swiss HIV Cohort Study

BACKGROUND

Advancements in access to antiretroviral therapy (ART) and human immunodeficiency virus (HIV) care have led to a decline in acquired immunodeficiency syndrome (AIDS)-related deaths among people with HIV (PWH) in Switzerland. However, data on the ongoing changes in causes of death among PWH over the past 15 years is scarce.

METHODS

We investigated all reported deaths in the Swiss HIV Cohort Study between 2005-2022. Causes of death were categorized using the Coding Causes of Death in HIV protocol. The statistical analysis included demographic stratification to identify time trends and logistic regression models to determine associated factors for the underlying cause of death.

RESULTS

In total, 1630 deaths were reported, with 23.7% of individuals assigned female at birth. Out of these deaths, 147 (9.0%) were HIV/AIDS-related, 373 (22.9%) due to non-AIDS, non-hepatic (NANH) cancers, 166 (10.2%) liver-related, and 158 (9.7%) cardiovascular-related. The median age at death increased from 45.0 [40.0,53.0] years in 2005-2007 to 61.0 [56.0,69.5] years in 2020-2022. HIV/AIDS and liver-related causes of death decreased, whereas deaths from NANH cancers increased, and cardiovascular-related deaths remained relatively stable.

CONCLUSION

The proportionally decreasing HIV/AIDS and liver-related deaths showcase the effectiveness of ART, comprehensive HIV patient care, and interventions targeting hepatitis C virus co-infection. Future research should focus on managing cancer and cardiovascular-related conditions as the new leading causes of death among PWH. Comprehensive healthcare strategies focusing on non-AIDS-related comorbidities, cancer management, and sustaining liver and cardiovascular health are needed to bridge the ongoing health disparities between PWH and the general population.

Quantifying and Predicting Ongoing Human Immunodeficiency Virus Type 1 Transmission Dynamics in Switzerland Using a Distance-Based Clustering Approach

BACKGROUND

Despite effective prevention approaches, ongoing human immunodeficiency virus 1 (HIV-1) transmission remains a public health concern indicating a need for identifying its drivers.

METHODS

We combined a network-based clustering method using evolutionary distances between viral sequences with statistical learning approaches to investigate the dynamics of HIV transmission in the Swiss HIV Cohort Study and to predict the drivers of ongoing transmission.

RESULTS

We found that only a minority of clusters and patients acquired links to new infections between 2007 and 2020. While the growth of clusters and the probability of individual patients acquiring new links in the transmission network was associated with epidemiological, behavioral, and virological predictors, the strength of these associations decreased substantially when adjusting for network characteristics. Thus, these network characteristics can capture major heterogeneities beyond classical epidemiological parameters. When modeling the probability of a newly diagnosed patient being linked with future infections, we found that the best predictive performance (median area under the curve receiver operating characteristic AUCROC = 0.77) was achieved by models including characteristics of the network as predictors and that models excluding them performed substantially worse (median AUCROC = 0.54).

CONCLUSIONS

These results highlight the utility of molecular epidemiology-based network approaches for analyzing and predicting ongoing HIV transmission dynamics. This approach may serve for real-time prospective assessment of HIV transmission.

Polygenic Risk Scores for Prediction of Subclinical Coronary Artery Disease in Persons With Human Immunodeficiency Virus (HIV): The Swiss HIV Cohort Study

BACKGROUND

In people with human immunodeficiency virus (HIV) (PWH), individual polygenic risk scores (PRSs) are associated with coronary artery disease (CAD) events. Whether PRSs are associated with subclinical CAD is unknown.

METHODS

In Swiss HIV Cohort Study participants of European descent, we defined subclinical CAD as presence of soft, mixed, or high-risk plaque (SMHRP) on coronary computed tomography (CT) angiography, or as participants in the top tertile of the study population's coronary artery calcium (CAC) score, using noncontrast CT. We obtained univariable and multivariable odds ratios (ORs) for subclinical CAD endpoints based on nongenetic risk factors, and validated genome-wide PRSs built from single nucleotide polymorphisms associated with CAD, carotid intima-media thickness (IMT), or longevity in the general population.

RESULTS

We included 345 genotyped participants (median age, 53 years; 89% male; 96% suppressed HIV RNA); 172 and 127 participants had SMHRP and CAC, respectively. CAD-associated PRS and IMT-associated PRS were associated with SMHRP and CAC (all P < .01), but longevity PRS was not. Participants with unfavorable CAD-PRS (top quintile) had an adjusted SMHRP OR = 2.58 (95% confidence interval [CI], 1.18-5.67), and a CAC OR = 3.95 (95% CI, 1.45-10.77) vs. bottom quintile. Unfavorable nongenetic risk (top vs. bottom quintile) was associated with adjusted SMHRP OR = 24.01 (95% CI, 9.75-59.11), and a CAC-OR = 65.07 (95% CI, 18.48-229.15). Area under the receiver operating characteristic curve increased when we added CAD-PRS to nongenetic risk factors (SMHRP: 0.75 and 0.78, respectively; CAC: 0.80 and 0.83, respectively).

CONCLUSIONS

In Swiss PWH, subclinical CAD is independently associated with an individual CAD-associated PRS. Combining nongenetic and genetic cardiovascular risk factors provided the most powerful subclinical CAD prediction.

Triggers of Change in Sexual Behavior Among People With HIV: The Swiss U U Statement and COVID-19 Compared

We assessed changes in sexual behavior among people with human immunodeficiency virus (HIV) over 20 years. Condom use with stable partners steadily declined from over 90 to 29 since the Swiss U U statement, with similar trajectories between men who have sex with men (MSM) and heterosexuals. Occasional partnership remained higher among MSM compared to heterosexuals even during coronavirus disease 2019 (COVID-19) social distancing.

Risk Factors and Incidence of Sexually Transmitted Infections in the Swiss HIV Cohort Study

Background

Sexually transmitted infections (STIs) are common among people with human immunodeficiency virus (PWH), but there are limited data about risk factors and incidence of STIs in large, representative cohort studies.

Methods

We assessed incidence and risk factors of STIs reported by treating physicians within the Swiss HIV Cohort Study (SHCS). Sexually transmitted infections and demographic, clinical, and behavioral characteristics were prospectively collected at 6-month follow-up visits between October 2017 and November 2019. We used multilevel Poisson regression to assess incidence rate ratios of different STIs.

Results

Among 10 140 study participants, a total of 1634 STIs in 1029 SHCS participants were reported over 17 766 person-years of follow up (PYFUP). The overall incidence of any reported STI was 91.9 per 1000 PYFU (95% confidence interval [CI], 85.8 -98.5). Among the 1634 STI episodes, there were 573 (35.1%) incident cases of syphilis, 497 gonorrhea (30.4%), and 418 chlamydia (25.6%). Men who have sex with men (MSM) younger than 50 years represented 21% of the study population, but accounted for 61% of reported STIs. Male sex (adjusted incidence rate ratio [aIRR], 2.03; 95% CI, 1.36-3.02), MSM (aIRR, 3.62; 95% CI, 2.88-4.55), age group 18-34 years (aIRR, 1.78; 95% CI, 1.51-2.10), history of sexual relationships with occasional partners (aIRR, 6.87; 95% CI, 5.40-8.73), and reporting injecting drug use (aIRR, 2.48; 95% CI, 1.91-3.23) were associated with a higher risk of incident STIs.

Conclusions

Sexually transmitted infections were frequent among PWH and varied considerably between age and risk groups. Screening programs and recommendations for STI testing need to be adapted according to risk factors and demographic characteristics.

A highly virulent variant of HIV-1 circulating in the Netherlands

We discovered a highly virulent variant of subtype-B HIV-1 in the Netherlands. One hundred nine individuals with this variant had a 0.54 to 0.74 log₁₀ increase (i.e., a ~3.5-fold to 5.5-fold increase) in viral load compared with, and exhibited CD4 cell decline twice as fast as, 6604 individuals with other subtype-B strains. Without treatment, advanced HIV-CD4 cell counts below 350 cells per cubic millimeter, with long-term clinical consequences-is expected to be reached, on average, 9 months after diagnosis for individuals in their thirties with this variant. Age, sex, suspected mode of transmission, and place of birth for the aforementioned 109 individuals were typical for HIV-positive people in the Netherlands, which suggests that the increased virulence is attributable to the viral strain. Genetic sequence analysis suggests that this variant arose in the 1990s from de novo mutation, not recombination, with increased transmissibility and an unfamiliar molecular mechanism of virulence.

Changes in alanine aminotransferase levels after switching from tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide (TAF) in HIV-positive people without viral hepatitis in the Swiss HIV Cohort Study

OBJECTIVES

We previously demonstrated an association between tenofovir disoproxil fumarate (TDF) and chronic liver enzyme elevation in the D:A:D study. The objective of the study was to assess changes in alanine aminotransferase (ALT) levels after switching from TDF to tenofovir alafenamide (TAF).

METHODS

We included Swiss HIV Cohort Study participants who switched from TDF to TAF with two or more ALT values in the 24 months before and two or more values in the 24 months after replacing TDF with TAF. Individuals with replicating viral hepatitis were excluded. Uni- and multivariable linear mixed models were used to explore changes in ALT values associated with switching from TDF to TAF, and to assess potential modifying effects.

RESULTS

A total of 1712 participants were included, contributing 6169 ALT values before and 5482 after switching. Median (interquartile range, IQR) age was 50 (42-57) years, and 75% were male. Median (IQR) ALT was 28 (22-38) U/L before and 24 (19-32) U/L after replacing TDF with TAF. ALT values decreased by 3.7 U/L (95% confidence interval: 3.2-4.2) after the switch. The median drop was larger in patients with chronic ALT elevation (defined as two or more elevated values for ≥ 6 months) compared with patients with normal ALT values (17.8 vs. 3.3 U/L, P < 0.001). We did not identify any major effect modifications of the ALT change with any of the potential variables studied.

CONCLUSIONS

Replacing TDF with TAF in HIV-monoinfected people led to a significant decrease in ALT values. Findings were not significantly affected by known risk factors for hepatotoxicity.

Alcohol consumption and neurocognitive deficits in people with well-treated HIV in Switzerland

Background

Hazardous alcohol consumption and HIV infection increase the risk of neurocognitive impairment (NCI). We examined the association between alcohol consumption and specific neurocognitive domain function in people with HIV (PWH) taking modern antiretroviral therapy.

Methods

The Neurocognitive Assessment in the Metabolic and Aging Cohort (NAMACO) study is a prospective, longitudinal, multicentre and multilingual (French, German and Italian) study of patients aged ≥45 years old enrolled in the Swiss HIV Cohort Study (SHCS). Baseline data from 981 study participants were examined. Five neurocognitive domains were evaluated: motor skills, speed of information processing, attention/working memory, executive function and verbal episodic memory. NCI was examined as binary (presence/absence) and continuous (mean z-score) outcomes against Alcohol Use Disorders Identification Test for Consumption (AUDIT-C) scores using logistic and linear regression models, respectively.

Results

Most participants (96.2%) had undetectable viral loads and 64% were aged >50 years old. Hazardous alcohol consumption was observed in 49.4% of participants and binge drinking in 4.2%. While alcohol consumption frequency and quantity were not associated with NCI, the practice of binge drinking was significantly associated with impaired motor skills and overall neurocognitive function in both binary (odds ratio, OR ≥2.0, P <0.05) and continuous (mean z-score difference -0.2 to -0.4, P ≤0.01) outcomes. A significant U-shaped distribution of AUDIT-C score was also observed for motor skills and overall neurocognitive function.

Conclusions

In this cohort of PWH with well-controlled HIV infection, NCI was associated with the practice of binge drinking rather than alcohol consumption frequency or quantity. Longitudinal analysis of alcohol consumption and NCI in this population is currently underway.

The association between depressive symptoms and neurocognitive impairment in people with well-treated HIV in Switzerland

BACKGROUND

Depression may contribute to neurocognitive impairment (NCI) in people with HIV (PWH). Attributing NCI to depression rather than to HIV is complicated as depression may be both a causal factor and an effect of NCI. This study aimed to determine the association between depressive symptoms and NCI among PWH with well-controlled infection.

METHODS

The Neurocognitive Assessment in the Metabolic and Ageing Cohort study is an ongoing, prospective, longitudinal study of PWH aged ≥45 years old nested within the Swiss HIV Cohort Study. Neurocognitive Assessment in the Metabolic and Ageing Cohort study participants underwent neurocognitive assessment and grading of depressive symptoms using the Centre for Epidemiological Studies Depression Scale. Neurocognitive impairment categories were defined using Frascati criteria. Participants with NCI related to neurological or psychiatric confounders other than depression were excluded. The cross-sectional association between the Centre for Epidemiological Studies Depression score and neurocognitive impairment was examined taking Centre for Epidemiological Studies Depression score as a continuous variable and then as a binary variable using two score thresholds, 16 and 27.

RESULTS

Excluding 79 participants with confounding factors, 902 participants were studied: 81% were men; 96% had plasma viral loads <50 copies/ml; 35% had neurocognitive impairment; 28% had Centre for Epidemiological Studies Depression scores ≥16. Higher Centre for Epidemiological Studies Depression scores were associated with female sex (p = 0.0003), non-Caucasian origin (p = 0.011) and current/past intravenous drug use (p = 0.002). Whilst neurocognitive impairment was associated with higher Centre for Epidemiological Studies Depression scores, the Centre for Epidemiological Studies Depression score was a poor predictor of having neurocognitive impairment (area under the ROC curve 0.604). Applying a Centre for Epidemiological Studies Depression score threshold of 16 predicted the presence of neurocognitive impairment with a sensitivity of 38.3% (specificity 77.2%), increasing the threshold to 27 lowered sensitivity to 15.4% (specificity 93.6%).

CONCLUSION

In this large cohort of PWH in Switzerland, we did not observe a Centre for Epidemiological Studies Depression score threshold that was sensitive in predicting neurocognitive impairment. As neurocognitive impairment was however associated with higher Centre for Epidemiological Studies Depression scores, the data support the screening for and treatment of depression among PWH diagnosed with neurocognitive impairment.

Antiretroviral Drugs Associated With Subclinical Coronary Artery Disease in the Swiss Human Immunodeficiency Virus Cohort Study

BACKGROUND

Coronary artery disease (CAD) events have been associated with certain antiretroviral therapy (ART) agents. In contrast, the influence of ART on subclinical atherosclerosis is not clear. The study objective was to assess the association between individual ART agents and the prevalence and extent of subclinical CAD.

METHODS

Coronary artery calcium (CAC) scoring and coronary computed tomography angiography (CCTA) were performed in ≥45-year-old Swiss Human Immunodeficiency Virus Cohort Study participants. The following subclinical CAD endpoints were analyzed separately: CAC score >0, any plaque, calcified plaque, noncalcified/mixed plaque, segment involvement score (SIS), and segment severity score (SSS). Logistic regression models calculated by inverse probability of treatment weights (IPTW) were used to explore associations between subclinical CAD and cumulative exposure to the 10 most frequently used drugs.

RESULTS

There were 403 patients who underwent CCTA. A CAC score >0 was recorded in 188 (47%), any plaque in 214 (53%), calcified plaque in 151 (38%), and noncalcified/mixed plaque in 150 (37%) participants. A CAC score >0 was negatively associated with efavirenz (IPTW adjusted odds ratio per 5 years 0.73, 95% confidence interval [CI] 0.56-0.96), tenofovir disoproxil fumarate (0.68, 95% CI 0.49-0.95), and lopinavir (0.64, 95% CI 0.43-0.96). Any plaque was negatively associated with tenofovir disoproxil fumarate (0.71, 95% CI 0.51-0.99). Calcified plaque was negatively associated with efavirenz (0.7, 95% CI 0.57-0.97). Noncalcified/mixed plaque was positively associated with abacavir (1.46, 95% CI 1.08-1.98) and negatively associated with emtricitabine (0.67, 95% CI 0.46-0.99). For SSS and SIS, we found no association with any drug.

CONCLUSIONS

An increased risk of noncalcified/mixed plaque was only found in patients exposed to abacavir. Emtricitabine was negatively associated with noncalcified/mixed plaque, while tenofovir disoproxil fumarate and efavirenz were negatively associated with any plaque and calcified plaque, respectively.

Longitudinal Progression of Subclinical Coronary Atherosclerosis in Swiss HIV-Positive Compared With HIV-Negative Persons Undergoing Coronary Calcium Score Scan and CT Angiography

Background

People with HIV (HIV+) may have increased cardiovascular event rates compared with HIV-negative (HIV-) persons. Cross-sectional data from the United States and Switzerland, based on coronary artery calcium scan (CAC) and coronary computed tomography angiography (CCTA), suggest, respectively, increased and similar prevalence of subclinical atherosclerosis in HIV+ vs HIV- persons.

Methods

We repeated CAC/CCTA in 340 HIV+ and 90 HIV- study participants >2 years after baseline CAC/CCTA. We assessed the association of HIV infection, Framingham risk score (FRS), and HIV-related factors with the progression of subclinical atherosclerosis.

Results

HIV+ were younger than HIV- participants (median age, 52 vs 56 years; P < .01) but had similar median 10-year FRS (8.9% vs 9.0%; P = .82); 94% had suppressed HIV viral load. In univariable and multivariable analyses, FRS was associated with the incidence rate ratio (IRR) of new subclinical atherosclerosis at the follow-up CAC/CCTA, but HIV infection was not: any plaque (adjusted IRR for HIV+ vs HIV- participants, 1.21; 95% CI, 0.62–2.35), calcified plaque (adjusted IRR for HIV+ vs HIV- participants, 1.06; 95% CI, 0.56–2), noncalcified/mixed plaque (adjusted IRR for HIV+ vs HIV- participants, 1.24; 95% CI, 0.69–2.21), and high-risk plaque (adjusted IRR for HIV+ vs HIV- participants, 1.46; 95% CI, 0.66–3.20). Progression of CAC score between baseline and follow-up CAC/CCTA was similar in HIV+ (median annualized change [interquartile range {IQR}], 0.41 [0–10.19]) and HIV- participants (median annualized change [IQR], 2.38 [0–16.29]; P = .11), as was progression of coronary segment severity score (HIV+: median annualized change [IQR], 0 [0–0.47]; HIV-: median annualized change [IQR], 0 [0–0.52]; P = .10) and coronary segment involvement score (HIV+: median annualized change [IQR], 0 [0–0.45]; HIV-: median annualized change [IQR], 0 [0–0.41]; P = .25).

Conclusions

In this longitudinal CAC/CCTA study from Switzerland, Framingham risk score was associated with progression of subclinical atherosclerosis, but HIV infection was not.

Changes in Renal Function After Switching From TDF to TAF in HIV-Infected Individuals: A Prospective Cohort Study

Background

Replacing tenofovir disoproxil fumarate (TDF) with tenofovir alafenamide (TAF) improves renal tubular markers in HIV-infected individuals but the impact on estimated glomerular filtration rate (eGFR) remains unclear.

Methods

In all participants from the Swiss HIV Cohort Study who switched from TDF to TAF-containing antiretroviral regimen or continued TDF, we estimated changes in eGFR and urine protein-to-creatinine ratio (UPCR) after 18 months using mixed-effect models.

Results

Of 3520 participants (26.6% women, median age 50 years), 2404 (68.5%) switched to TAF. Overall, 1664 (47.3%) had an eGFR &lt;90 mL/min and 1087 (30.9%) an UPCR ≥15 mg/mmol. In patients with baseline eGFR ≥90 mL/min, eGFR decreased with the use of TDF and TAF (−1.7 mL/min). Switching to TAF was associated with increases in eGFR of 1.5 mL/min (95% confidence interval [CI], .5–2.5) if the baseline eGFR was 60–89 mL/min, and 4.1 mL/min (95% CI, 1.6–6.6) if &lt;60 mL/min. In contrast, eGFR decreased by 5.8 mL/min (95% CI, 2.3–9.3) with continued use of TDF in individuals with baseline eGFR &lt;60 mL/min. UPCR decreased after replacing TDF by TAF, independent of baseline eGFR.

Conclusions

Switching from TDF to TAF improves eGFR and proteinuria in patients with renal dysfunction.

How helpful are the European AIDS Clinical Society cognitive screening questions in predicting cognitive impairment in an aging, well-treated HIV-positive population?

Objectives

Diagnosing neurocognitive impairment (NCI) in HIV infection requires time‐consuming neuropsychological assessment. Screening tools are needed to identify when neuropsychological referral is indicated. We examined the positive and negative predictive values (PPVs and NPVs, respectively) of the three European AIDS Clinical Society (EACS) screening questions in identifying NCI.

Methods

The Neurocognitive Assessment in the Metabolic and Aging Cohort (NAMACO) study recruited patients aged ≥45 years enrolled in the Swiss HIV Cohort Study between 1 May 2013 and 30 November 2016. NAMACO participants (1) answered EACS screening questions, (2) underwent standardized neuropsychological assessment and (3) completed self‐report forms [Center for Epidemiologic Studies Depression Scale (CES‐D)] rating mood. NCI categories were defined using Frascati criteria. PPVs and NPVs of the EACS screening questions in identifying NCI categories were calculated.

Results

Of 974 NAMACO participants with complete EACS screening question data, 244 (25.1%) expressed cognitive complaints in answer to at least one EACS screening question, of whom 51.3% had NCI (26.1% HIV‐associated and 25.2% related to confounding factors). The PPV and NPV of the EACS screening questions in identifying HIV‐associated NCI were 0.35 and 0.7, respectively. Restricting analysis to NCI with functional impairment or related to confounding factors, notably depression, the NPV was 0.90. Expressing cognitive complaints for all three EACS screening questions was significantly associated with depression (P < 0.001).

Conclusions

The EACS screening questions had an NPV of 0.7 for excluding patients with HIV‐associated NCI as defined by Frascati criteria. The PPV and NPV may improve if NCI diagnoses are based on new criteria.

Subclinical coronary artery disease in Swiss HIV-positive and HIV-negative persons

Aims

HIV-positive persons have increased cardiovascular event rates but data on the prevalence of subclinical atherosclerosis compared with HIV-negative persons are not uniform. We assessed subclinical atherosclerosis utilizing coronary artery calcium (CAC) scoring and coronary computed tomography angiography (CCTA) in 428 HIV-positive participants of the Swiss HIV Cohort Study and 276 HIV-negative controls concurrently referred for clinically indicated CCTA.

Methods and results

We assessed the association of HIV infection, cardiovascular risk profile, and HIV-related factors with subclinical atherosclerosis in univariable and multivariable analyses. HIV-positive participants (median duration of HIV infection, 15 years) were younger than HIV-negative participants (median age 52 vs. 56 years; P < 0.01) but had similar median 10-year Framingham risk scores (9.0% vs. 9.7%; P = 0.40). The prevalence of CAC score >0 (53% vs. 56.2%; P = 0.42) and median CAC scores (47 vs. 47; P = 0.80) were similar, as was the prevalence of any, non-calcified/mixed, and high-risk plaque. In multivariable adjusted analysis, HIV-positive participants had a lower prevalence of calcified plaque than HIV-negative participants [36.9% vs. 48.6%, P < 0.01; adjusted odds ratio (aOR) 0.57; 95% confidence interval (CI) 0.40-0.82; P < 0.01], lower coronary segment severity score (aOR 0.72; 95% CI 0.53-0.99; P = 0.04), and lower segment involvement score (aOR 0.71, 95% CI 0.52-0.97; P = 0.03). Advanced immunosuppression was associated with non-calcified/mixed plaque (aOR 1.97; 95% CI 1.09-3.56; P = 0.02).

Conclusion

HIV-positive persons in Switzerland had a similar degree of non-calcified/mixed plaque and high-risk plaque, and may have less calcified coronary plaque, and lower coronary atherosclerosis involvement and severity scores than HIV-negative persons with similar Framingham risk scores.

Rates and predictors of switching to tenofovir alafenamide-containing ART in a nationwide cohort

Background

Tenofovir alafenamide (TAF)-containing combinations were introduced in Switzerland after October 2016 and are recommended over tenofovir disoproxil fumarate (TDF) in patients with osteoporosis or impaired renal function.

Methods

We included all participants of the Swiss HIV Cohort Study on TDF-containing antiretroviral therapy with follow-up visits after January 2016. We determined the proportion of switches from TDF to TAF overall, and among patients with risk factors for TDF toxicity, including osteoporosis, impaired renal function or marked proteinuria. We used multivariable logistic regression to explore predictors of switching from TDF to TAF.

Results

We included 5′012 patients, of whom 652 (13.0%) had risk factors for TDF toxicity. A switch from TDF to TAF was undertaken in 2′796 (55.8%) individuals overall, and in 465 (71.3%) with risk factors. Predictors of switching to TAF were male sex (adjusted odds ratio 1.27, 95% confidence interval 1.07–1.50), age > 50 years (1.43, 1.23–1.66) and the presence of risk factors for TDF toxicity (2.21, 1.77–2.75). In contrast, patients with a non-nucleoside reverse transcriptase inhibitor (NNRTI)-based single-pill regimen (0.11, 0.09–0.13), those treated in non-tertiary care centers (0.56, 0.46–0.70), as well as those with CD4 cell counts below 500/μL (0.77, 0.66–0.90) and with chronic hepatitis C infection (0.66, 0.54–0.80) were most likely to stay on TDF.

Conclusions

Over 50% of patients on TDF-containing therapy, including the majority of patients at risk for TDF toxicity, were switched to TAF within two years of its introduction in Switzerland. Individuals on NNRTI-based single-pill regimens were most likely to remain on TDF.

The Neurocognitive Assessment in the Metabolic and Aging Cohort (NAMACO) study: baseline participant profile

Objectives

The aim of the study was to examine baseline neurocognitive impairment (NCI) prevalence and factors associated with NCI among patients enrolled in the Neurocognitive Assessment in the Metabolic and Aging Cohort (NAMACO) study.

Methods

The NAMACO study is an ongoing, prospective, longitudinal, multicentre and multilingual (German, French and Italian) study within the Swiss HIV Cohort Study. Between 1 May 2013 and 30 November 2016, 981 patients ≥ 45 years old were enrolled in the study. All underwent standardized neuropsychological (NP) assessment by neuropsychologists. NCI was diagnosed using Frascati criteria and classified as HIV‐associated or as related to other factors. Dichotomized analysis (NCI versus no NCI) and continuous analyses (based on NP test z‐score means) were performed.

Results

Most patients (942; 96.2%) had viral loads < 50 HIV‐1 RNA copies/mL. NCI was identified in 390 patients (39.8%): 263 patients (26.8%) had HIV‐associated NCI [249 patients (25.4%) had asymptomatic neurocognitive impairment (ANI)] and 127 patients (13%) had NCI attributable to other factors, mainly psychiatric disorders. There was good correlation between dichotomized and continuous analyses, with NCI associated with older age, non‐Caucasian ethnicity, shorter duration of education, unemployment and longer antiretroviral therapy duration.

Conclusions

In this large sample of aging people living with HIV with well‐controlled infection in Switzerland, baseline HIV‐associated NCI prevalence, as diagnosed after formal NP assessment, was 26.8%, with most cases being ANI. The NAMACO study data will enable longitudinal analyses within this population to examine factors affecting NCI development and course.

Persistent disparities in antiretroviral treatment (ART) coverage and virological suppression across Europe, 2004 to 2015

Background: Direct comparisons between countries in core HIV care parameters are often hampered by differences in data collection. Aim: Within the EuroSIDA study, we compared levels of antiretroviral treatment (ART) coverage and virological suppression (HIV RNA < 500 copies/mL) across Europe and explored temporal trends. Methods: In three cross-sectional analyses in 2004–05, 2009–10 and 2014–15, we assessed country-specific percentages of ART coverage and virological suppression among those on ART. Temporal changes were analysed using logistic regression. Results: Overall, the percentage of people on ART increased from 2004–05 (67.8%) to 2014–15 (78.2%), as did the percentage among those on ART who were virologically suppressed (75.2% in 2004–05, 87.7% in 2014–15). However, the rate of improvement over time varied significantly between regions (p < 0.01). In 2014–15, six of 34 countries had both ART coverage and virological suppression of above 90% among those on ART. The pattern varied substantially across clinics within countries, with ART coverage ranging from 61.9% to 97.0% and virological suppression from 32.2% to 100%. Compared with Western Europe (as defined in this study), patients in other regions were less likely to be virologically suppressed in 2014–15, with the lowest odds of suppression (adjusted odds ratio = 0.16; 95% confidence interval (CI): 0.13–0.21) in Eastern Europe. Conclusions: Despite overall improvements over a decade, we found persistent disparities in country-specific estimates of ART coverage and virological suppression. Underlying reasons for this variation warrant further analysis to identify a best practice and benchmark HIV care across EuroSIDA.

Predictors of Ischemic and Hemorrhagic Strokes Among People Living With HIV: The D:A:D International Prospective Multicohort Study

BACKGROUND

Hypertension is a stronger predictor of hemorrhagic than ischemic strokes in the general population. We aimed to identify whether hypertension or other risk factors, including HIV-related factors, differ in their associations with stroke subtypes in people living with HIV (PLWHIV).

METHODS

HIV-1-positive individuals from the Data collection on Adverse events of anti-HIV Drugs (D:A:D) study were followed from the time of first blood pressure (BP) measurement after 1/1/1999 or study entry until the first of a validated stroke, 6 months after last follow-up or 1/2/2014. Stroke events were centrally validated using standardized criteria. Hypertension was defined as one systolic BP ≥ 140 mm Hg and/or diastolic BP ≥ 90 mm Hg. Poisson and Cox proportional hazards regression models determined associations of established cerebro/cardiovascular disease and HIV-related risk factors with stroke and tested whether these differed by stroke subtype.

FINDINGS

590 strokes (83 hemorrhagic, 296 ischemic, 211 unknown) occurred over 339,979 person-years (PYRS) (incidence rate/1000 PYRS 1.74 [95% confidence interval (CI) 1.60-1.88]). Common predictors of both hemorrhagic and ischemic strokes were hypertension (relative hazard 3.55 [95% CI 2.29-5.50] and 2.24 [1.77-2.84] respectively) and older age (1.28 [1.17-1.39] and 1.19 [1.12-1.25]). Male gender (1.62 [1.14-2.31] and 0.60 [0.35-0.91]), previous cardiovascular events (4.03 [2.91-5.57] and 1.44 [0.66-3.16]) and smoking (1.90 [1.41-2.56] and 1.08 [0.68-1.71]) were stronger predictors of ischemic then hemorrhagic strokes, whereas hypertension, hepatitis C (1.32 [0.72-2.40] and 0.46 [0.30-0.70]) and estimated glomerular filtration rate < 60 mL/min/1.72 m³ (4.80 [2.47-9.36] and 1.04 [0.67-1.60]) were stronger predictors of hemorrhagic than ischemic strokes. A CD4 count < 200 cells/μL was associated with an increased risk of hemorrhagic stroke only.

INTERPRETATION

Risk factors for stroke may differ by subtype in PLWHIV, emphasizing the importance of further research to increase the precision of stroke risk estimation.

Subclinical Atherosclerosis Imaging in People Living with HIV

In many, but not all studies, people living with HIV (PLWH) have an increased risk of coronary artery disease (CAD) events compared to the general population. This has generated considerable interest in the early, non-invasive detection of asymptomatic (subclinical) atherosclerosis in PLWH. Ultrasound studies assessing carotid artery intima-media thickness (CIMT) have tended to show a somewhat greater thickness in HIV+ compared to HIV−, likely due to an increased prevalence of cardiovascular (CV) risk factors in PLWH. Coronary artery calcification (CAC) determination by non-contrast computed tomography (CT) seems promising to predict CV events but is limited to the detection of calcified plaque. Coronary CT angiography (CCTA) detects calcified and non-calcified plaque and predicts CAD better than either CAC or CIMT. A normal CCTA predicts survival free of CV events over a very long time-span. Research imaging techniques, including black-blood magnetic resonance imaging of the vessel wall and 18F-fluorodeoxyglucose positron emission tomography for the assessment of arterial inflammation have provided insights into the prevalence of HIV-vasculopathy and associated risk factors, but their clinical applicability remains limited. Therefore, CCTA currently appears as the most promising cardiac imaging modality in PLWH for the evaluation of suspected CAD, particularly in patients <50 years, in whom most atherosclerotic coronary lesions are non-calcified.

Cross-Sectional and Cumulative Longitudinal Central Nervous System Penetration Effectiveness Scores Are Not Associated With Neurocognitive Impairment in a Well Treated Aging Human Immunodeficiency Virus-Positive Population in Switzerland

Background

Neurocognitive impairment (NCI) in people with human immunodeficiency virus (PWH) remains a concern despite potent antiretroviral therapy (ART). Higher central nervous system (CNS) penetration effectiveness (CPE) scores have been associated with better CNS human immunodeficiency virus (HIV) replication control, but the association between CPE and NCI remains controversial.

Methods

The Neurocognitive Assessment in the Metabolic and Aging Cohort (NAMACO) study is a subgroup of the Swiss HIV Cohort Study (SHCS) that invited patients aged ≥45 years enrolled in the SHCS and followed-up at NAMACO-affiliated centers in Switzerland to participate between May 2013 and November 2016. In total, 981 patients were enrolled, all of whom underwent standardized neurocognitive assessment. Neurocognitive impairment, if present, was characterized using Frascati criteria. The CPE scores of NAMACO study participants with undetectable plasma HIV-ribonucleic acid at enrollment (909 patients) were analyzed. Cross-sectional CPE scores (at neurocognitive assessment) were examined as potential predictors of NCI in multivariate logistic regression models. The analysis was then repeated taking CPE as a cumulative score (summarizing CPE scores from ART initiation to the time of neurocognitive assessment).

Results

Most patients were male (80%) and Caucasian (92%). Neurocognitive impairment was present in 40%: 27% with HIV-associated NCI (mostly asymptomatic neurocognitive impairment), and 13% with NCI related to other factors. None of the CPE scores, neither cross-sectional nor cumulative, was statistically significantly associated with NCI.

Conclusions

In this large cohort of aviremic PWH, we observed no association between NCI, whether HIV-associated or related to other factors, and CPE score, whether cross-sectional or cumulative.

HIV and Aging - Perhaps Not as Dramatic as We Feared?

Ever since the introduction of highly active antiretroviral therapy (ART) in 1995, HIV infection has been linked to "metabolic" complications (insulin resistance, dyslipidemia, osteoporosis, and others). Studies suggested increased rates of myocardial infarction, renal insufficiency, neurocognitive dysfunction, and fractures in HIV-postitive patients. Even long-term suppression of HIV seemed to be accompanied by an excess of deleterious inflammation that could promote these complications. The aims of this viewpoint paper are to summarize recent data and to examine the possibility that the problem of aging-related morbidity in HIV might not be as dramatic as previously believed.

Incidental Findings on Coronary Computed Tomography Angiography in Human Immunodeficiency Virus (HIV)-Positive and HIV-Negative Persons

Background

Incidental findings on coronary computed tomography angiography (CCTA) have a great impact on the benefits and costs of testing for cardiovascular disease. The number of incidental findings might be increased in human immunodeficiency virus (HIV)-positive individuals compared with the general population. Data are limited regarding the association between incidental findings and HIV infection.

Methods

We assessed the prevalence and factors associated with incidental findings among HIV-positive and HIV-negative participants ≥45 years undergoing CCTA. Logistic regression was performed to evaluate the factors associated with incidental findings in the HIV-positive and HIV-negative groups. For the analysis of the HIV effect, a propensity score-matched dataset of HIV-positive/HIV-negative participants was used.

Results

We included 553 participants, 341 with and 212 without HIV infection. Incidental findings were observed in 291 of 553 (53%) patients. In 42 of 553 (7.6%) participants, an incidental finding resulted in additional workup. A malignancy was diagnosed in 2 persons. In the HIV-positive group, age (1.31 per 5 years, 1.10–1.56) and smoking (2.29, 1.43–3.70) were associated with incidental findings; in the HIV-negative group, age (1.26, 1.01–1.59) and a CAC score >0 (2.08, 1.09–4.02) were associated with incidental findings. Human immunodeficiency virus seropositivity did not affect the risk of incidental findings.

Conclusions

Incidental findings were highly prevalent among HIV-positive and HIV-negative persons. Human immunodeficiency virus infection was not associated with an increased risk of incidental findings.

Dietary Patterns and Physical Activity Correlate With Total Cholesterol Independently of Lipid-Lowering Drugs and Antiretroviral Therapy in Aging People Living With Human Immunodeficiency Virus

Background

Hypercholesterolemia is a well established risk factor for coronary heart disease and is highly prevalent among human immunodeficiency virus (HIV)-positive persons. Antiretroviral therapy (ART) can both directly modify total cholesterol and have drug-drug interactions with statins. This makes investigating modifiable behavioral predictors of total cholesterol a pertinent task.

Methods

To explore the association between diet and physical activity with cross-sectionally measured total cholesterol, we administered a validated Food-Frequency-Questionnaire to participants of the Swiss HIV Cohort Study ≥45 years old. Linear mixed-effects models were applied to explore the associations between dietary patterns and physical activity with total cholesterol, after adjustment for clinical and demographic covariates.

Results

In total, 395 patients were included. Forty percent (158 of 395) had elevated total cholesterol (>5.2 mmol/L), and 41% (164 of 395) were not regularly physically active. In multivariable analysis, 2 factors were positively associated with total cholesterol; female sex (β = 0.562; 95% confidence interval [CI], 0.229–0.896) and the combined consumption of meat, refined/milled grains, carbonated beverages, and coffee (β = 0.243; 95% CI, 0.047–0.439). On the other hand, regular physical activity (β = −0.381; 95% CI, −0.626 to −0.136), lipid-lowering drugs (β = −0.443; 95% CI −0.691 to −0.196), ART containing tenofovir (β = −0.336; 95% CI −0.554 to −0.118), and black ethnicity (β = −0.967; 95% CI −1.524 to −0.410) exhibited a negative association.

Conclusions

We found independent associations between certain dietary patterns and physical activity with total cholesterol. Increasing physical activity might achieve cardiovascular and other health benefits in HIV-positive individuals. The clinical relevance of the identified dietary patterns requires further investigation in prospective cohort studies and randomized controlled trials.

Gender differences in the use of cardiovascular interventions in HIV-positive persons; the D:A:D Study

INTRODUCTION

There is paucity of data related to potential gender differences in the use of interventions to prevent and treat cardiovascular disease (CVD) among HIV-positive individuals. We investigated whether such differences exist in the observational D:A:D cohort study.

METHODS

Participants were followed from study enrolment until the earliest of death, six months after last visit or February 1, 2015. Initiation of CVD interventions [lipid-lowering drugs (LLDs), angiotensin-converting enzyme inhibitors (ACEIs), anti-hypertensives, invasive cardiovascular procedures (ICPs) were investigated and Poisson regression models calculated whether rates were lower among women than men, adjusting for potential confounders.

RESULTS

Women (n = 12,955) were generally at lower CVD risk than men (n = 36,094). Overall, initiation rates of CVD interventions were lower in women than men; LLDs: incidence rate 1.28 [1.21, 1.35] vs. 2.40 [2.34, 2.46]; ACEIs: 0.88 [0.82, 0.93] vs. 1.43 [1.39, 1.48]; anti-hypertensives: 1.40 [1.33, 1.47] vs. 1.72 [1.68, 1.77] and ICPs: 0.08 [0.06, 0.10] vs. 0.30 [0.28, 0.32], and this was also true for most CVD interventions when exclusively considering periods of follow-up for which individuals were at high CVD risk. In fully adjusted models, women were less likely to receive CVD interventions than men (LLDs: relative rate 0.83 [0.78, 0.88]; ACEIs: 0.93 [0.86, 1.01]; ICPs: 0.54 [0.43, 0.68]), except for the receipt of anti-hypertensives (1.17 [1.10, 1.25]).

CONCLUSION

The use of most CVD interventions was lower among women than men. Interventions are needed to ensure that all HIV-positive persons, particularly women, are appropriately monitored for CVD and, if required, receive appropriate CVD interventions.

Trends in HCV treatment uptake, efficacy and impact on liver fibrosis in the Swiss HIV Cohort Study

BACKGROUND & AIMS

Hepatitis C virus (HCV) therapies with interferon-free second-generation direct-acting antivirals (DAAs) are highly effective and well tolerated. They have the potential to increase treatment eligibility and efficacy in HIV-infected patients. We assessed the impact of DAAs on treatment uptake and efficacy, as well as its impact on the burden of liver disease in the Swiss HIV Cohort Study (SHCS).

METHODS

We describe clinical and virological characteristics of patients treated with second-generation DAAs. We compared treatment incidence, sustained virological response (SVR)12 and liver fibrosis stages between three time periods: period 1, 01/2009-08/2011 (prior to the availability of DAAs); period 2, 09/2011-03/2014 (first generation DAAs); period 3, 04/2014-12/2015 (second generation DAAs).

RESULTS

At the beginning of the third period, 876 SHCS participants had a chronic HCV infection of whom 180 (20%) started treatment with a second-generation DAA. Three-quarters of them had advanced liver fibrosis (Metavir ≥ F3) of whom 80% were cirrhotics. SVR12 was achieved in 173/180 (96%) patients, three patients died and four experienced a virological failure. Over the three time periods, treatment uptake (4.5/100 py, 5.7/100 py, 22.4/100 py) and efficacy (54%, 70%, 96% SVR12) continuously increased. The proportion of cirrhotic patients with replicating HCV infection in the SHCS declined from 25% at the beginning to 12% at the end of the last period.

CONCLUSIONS

After the introduction of second-generation DAAs, we observed an increase in treatment uptake and efficacy which resulted in a significant reduction in the number of cirrhotic patients with a replicating HCV infection in the SHCS.

Hepatitis C Infection and the Risk of Non-Liver-Related Morbidity and Mortality in HIV-Infected Persons in the Swiss HIV Cohort Study

Background

Hepatitis C virus (HCV) infection has been associated with increased non-liver-related morbidity and mortality. However, studies have yielded inconsistent results.

Methods

The incidence of clinical events in human immunodeficiency virus (HIV)–infected HCV-seropositive and incidence density–matched HCV-seronegative participants of the Swiss HIV Cohort Study from August 1994 to December 2014 was studied. We compared (1) HCV-seropositive with HCV-seronegative participants and (2) HCV-viremic with successfully treated nonviremic patients. Poisson regression was used to assess differences between these groups.

Results

We included 2503 HCV-seropositive participants (540 with spontaneous HCV clearance, 1294 untreated HCV RNA positive, 345 treated with sustained virologic response [SVR], 43 during treatment, and 281 treated without SVR), and 2503 HCV-seronegative controls. After a mean follow-up of 8.2 years, we observed (HCV seropositive and HCV seronegative, respectively) 107 and 18 liver events, 41 and 14 kidney events, 230 and 121 osteoporosis/fractures, 82 and 94 diabetes mellitus, 114 and 129 cardiovascular events, 119 and 147 non-AIDS malignancies, 162 and 126 Centers for Disease Control and Prevention HIV category B/C events, 106 and 10 liver-related deaths, and 227 and 218 non-liver-related deaths. Compared with HCV-negative controls, HCV-seropositive participants had an increased risk of liver events (incidence rate ratio [IRR], 6.29 [95% confidence interval {CI}, 3.52–11.22]), liver-related death (IRR, 8.24 [95% CI, 3.61–18.83]), kidney events (IRR, 2.43 [95% CI, 1.11–5.33]), and osteoporosis/fracture (IRR, 1.43 [95% CI, 1.03–2.01]). Among HCV-seropositive individuals, treated participants without SVR vs those with SVR had a higher risk of liver events (IRR, 6.79 [95% CI, 2.33–19.81]), liver-related death (IRR, 3.29 [95% CI, 1.35–8.05]), and diabetes mellitus (IRR, 4.62 [95% CI, 1.53–13.96]). Similar but not statistically significant differences were found between untreated HCV RNA–positive patients and those with SVR.

Conclusions

While HCV exposure was associated with an increased risk of kidney disease and osteoporosis/fracture, this risk did not seem to be dependent of persistent HCV RNA. Successful HCV treatment was associated with a lower incidence of liver disease, liver-related death, and diabetes mellitus, whereas the other conditions studied were less affected.

Effect of Immediate Initiation of Antiretroviral Treatment in HIV-Positive Individuals Aged 50 Years or Older

BACKGROUND

Clinical guidelines recommend immediate initiation of combined antiretroviral therapy for all HIV-positive individuals. However, those guidelines are based on trials of relatively young participants.

METHODS

We included HIV-positive antiretroviral therapy-naive, AIDS-free individuals aged 50-70 years after 2004 in the HIV-CAUSAL Collaboration. We used the parametric g-formula to estimate the 5-year risk of all-cause and non-AIDS mortality under (1) immediate initiation at baseline and initiation at CD4 count, (2) <500 cells/mm, and (3) <350 cells/mm. Results were presented separately for the general HIV population and for a US Veterans cohort with high mortality.

RESULTS

The study included 9596 individuals (28% US Veterans) with median (interquantile range) age of 55 (52-60) years and CD4 count of 336 (182-513) at baseline. The 5-year risk of all-cause mortality was 0.40% (95% confidence interval (CI): 0.10 to 0.71) lower for the general HIV population and 1.61% (95% CI: 0.79 to 2.67) lower for US Veterans when comparing immediate initiation vs initiation at CD4 <350 cells/mm. The 5-year risk of non-AIDS mortality was 0.17% (95% CI: -0.07 to 0.43) lower for the general HIV population and 1% (95% CI: 0.31 to 2.00) lower for US Veterans when comparing immediate initiation vs initiation at CD4 <350 cells/mm.

CONCLUSIONS

Immediate initiation seems to reduce all-cause and non-AIDS mortality in patients aged 50-70 years.

Factors associated with syphilis incidence in the HIV-infected in the era of highly active antiretrovirals

After several years of steady decline, syphilis is reemerging globally as a public health hazard, especially among people living with human immunodeficiency virus (HIV). Syphilis resurgence is observed mainly in men who have sex with men (MSM), yet other transmission groups are affected too. In this manuscript, we study the factors associated with syphilis incidence in the Swiss HIV cohort study in the era of highly effective antiretrovirals. Using parametric interval censored models with fixed and time-varying covariates, we studied the immunological, behavioral, and treatment-related elements associated with syphilis incidence in 3 transmission groups: MSM, heterosexuals, and intravenous drug users. Syphilis incidence has been increasing annually since 2005, with up to 74 incident cases per 1000 person-years in 2013, with MSM being the population with the highest burden (92% of cases). While antiretroviral treatment (ART) in general did not affect syphilis incidence, nevirapine (NVP) was associated with a lower hazard of syphilis incidence (multivariable hazard ratio 0.5, 95% confidence interval 0.2-1.0). We observed that condomless sex and younger age were associated with higher syphilis incidence. Moreover, time-updated CD4, nadir CD4, and CD8 cell counts were not associated with syphilis incidence. Finally, testing frequency higher than the recommended once a year routine testing was associated with a 2-fold higher risk of acquiring syphilis. Condomless sex is the main driver of syphilis resurgence in the Swiss HIV Cohort study; ART and immune reconstitution provide no protection against syphilis. This entails targeted interventions and frequent screening of high-risk populations. There is no known effect of NVP on syphilis; therefore, further clinical, epidemiological, and microbiological investigation is necessary to validate our observation.

Liver fibrosis in treatment-naïve HIV-infected and HIV/HBV co-infected patients: Zambia and Switzerland compared

OBJECTIVE

To examine the association between hepatitis B virus (HBV) infection and liver fibrosis in HIV-infected patients in Zambia and Switzerland.

METHODS

HIV-infected adults starting antiretroviral therapy in two clinics in Zambia and Switzerland were included. Liver fibrosis was evaluated using the aspartate aminotransferase-to-platelet-ratio index (APRI), with a ratio >1.5 defining significant fibrosis and a ratio >2.0 indicating cirrhosis. The association between hepatitis B surface antigen (HBsAg) positivity, HBV replication, and liver fibrosis was examined using logistic regression.

RESULTS

In Zambia, 96 (13.0%) of 739 patients were HBsAg-positive compared to 93 (4.5%) of 2058 in Switzerland. HBsAg-positive patients were more likely to have significant liver fibrosis than HBsAg-negative ones: the adjusted odds ratio (aOR) was 3.25 (95% confidence interval (CI) 1.44-7.33) in Zambia and 2.50 (95% CI 1.19-5.25) in Switzerland. Patients with a high HBV viral load (≥20000 IU/ml) were more likely to have significant liver fibrosis compared to HBsAg-negative patients or patients with an undetectable viral load: aOR 3.85 (95% CI 1.29-11.44) in Zambia and 4.20 (95% CI 1.64-10.76) in Switzerland. In both settings, male sex was a strong risk factor for significant liver fibrosis.

CONCLUSIONS

Despite the differences in HBV natural history between Sub-Saharan Africa and Europe, the degree of liver fibrosis and the association with important risk factors were similar.

Contribution of Genetic Background and Clinical Risk Factors to Low-Trauma Fractures in Human Immunodeficiency Virus (HIV)-Positive Persons: The Swiss HIV Cohort Study

Background. The impact of human genetic background on low-trauma fracture (LTF) risk has not been evaluated in the context of human immunodeficiency virus (HIV) and clinical LTF risk factors.

Methods. In the general population, 6 common single-nucleotide polymorphisms (SNPs) associate with LTF through genome-wide association study. Using genome-wide SNP arrays and imputation, we genotyped these SNPs in HIV-positive, white Swiss HIV Cohort Study participants. We included 103 individuals with a first, physician-validated LTF and 206 controls matched on gender, whose duration of observation and whose antiretroviral therapy start dates were similar using incidence density sampling. Analyses of nongenetic LTF risk factors were based on 158 cases and 788 controls.

Results. A genetic risk score built from the 6 LTF-associated SNPs did not associate with LTF risk, in both models including and not including parental hip fracture history. The contribution of clinical LTF risk factors was limited in our dataset.

Conclusions. Genetic LTF markers with a modest effect size in the general population do not improve fracture prediction in persons with HIV, in whom clinical LTF risk factors are prevalent in both cases and controls.

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.

Drug safety of macrolide and quinolone antibiotics in a tertiary care hospital: administration of interacting co-medication and QT prolongation

PURPOSE

Some macrolide and quinolone antibiotics (MQABs) are associated with QT prolongation and life-threatening torsade de pointes (TdP) arrhythmia. MQAB may also inhibit cytochrome P450 isoenzymes and thereby cause pharmacokinetic drug interactions (DDIs). There is limited data on the frequency and management of such risks in clinical practice. We aimed to quantify co-administration of MQAB with interacting drugs and associated adverse drug reactions.

METHODS

We conducted an observational study within our pharmacoepidemiological database derived from electronic medical records of a tertiary care hospital. Among all users of MQAB associated with TdP, we determined the prevalence of additional QT-prolonging drugs and risk factors and identified contraindicated co-administrations of simvastatin, atorvastatin, or tizanidine. Electrocardiographic (ECG) monitoring and associated adverse events were validated in medical records.

RESULTS

Among 3444 administered courses of clarithromycin, erythromycin, azithromycin, ciprofloxacin, levofloxacin, or moxifloxacin, there were 1332 (38.7 %) with concomitant use of additional QT-prolonging drugs. Among those, we identified seven cases of drug-related QT prolongation, but 49.1 % had no ECG monitoring. Of all MQAB users, 547 (15.9 %) had hypokalemia. Forty-four MQAB users had contraindicated co-administrations of simvastatin, atorvastatin, or tizanidine and three of those related adverse drug reactions.

CONCLUSION

In the studied real-life setting, we found a considerable number of MQAB users with additional risk factors for TdP but no ECG monitoring. However, adverse drug reactions were rarely found, and costs vs. benefits of ECG monitoring have to be weighted. In contrast, avoidable risk factors and selected contraindicated pharmacokinetic interactions are clear targets for implementation as automated alerts in electronic prescribing systems.

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.

Antiretroviral Drugs and Risk of Chronic Alanine Aminotransferase Elevation in Human Immunodeficiency Virus (HIV)-Monoinfected Persons: The Data Collection on Adverse Events of Anti-HIV Drugs Study

Background. Although human immunodeficiency virus (HIV)-positive persons on antiretroviral therapy (ART) frequently have chronic liver enzyme elevation (cLEE), the underlying cause is often unclear.

Methods. Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) Study participants without chronic viral hepatitis were observed to the earliest of cLEE (elevated aminotransferase ≥6 months), death, last follow-up, or January 2, 2014. Antiretroviral treatment exposure was categorized as follows: no exposure and ongoing short- and long-term exposure (<2 or ≥2 years) after initiation. Association between development of cLEE and ART exposure was investigated using Poisson regression.

Results. Among 21 485 participants observed for 105 413 person-years (PY), 6368 developed cLEE (incidence 6.04/100 PY; 95% confidence interval [CI], 5.89–6.19). Chronic liver enzyme elevation was associated with short-and long-term exposure to didanosine (<2 years rate ratio [RR] = 1.29, 95% CI, 1.11–1.49; >2 years RR = 1.26, 95% CI, 1.13–1.41); stavudine (<2 years RR = 1.51, 95% CI, 1.26–1.81; >2 years RR = 1.17, 95% CI, 1.03–1.32), and tenofovir disoproxil fumarate (<2 years RR = 1.55, 95% CI, 1.40–1.72; >2 years RR = 1.18, 95% CI, 1.05–1.32), but only short-term exposure to nevirapine (<2 years RR = 1.44, 95% CI, 1.29–1.61), efavirenz (<2 years RR = 1.14, 95% CI, 1.03–1.26), emtricitabine (<2 years RR = 1.18, 95% CI, 1.04–1.33), and atazanavir (<2 years RR = 1.20, 95% CI, 1.04–1.38). Chronic liver enzyme elevation was not associated with use of lamivudine, abacavir, and other protease inhibitors. Mortality did not differ between participants with and without cLEE.

Conclusions. Although didanosine, stavudine, nevirapine, and efavirenz have been described to be hepatotoxic, we additionally observed a consistent association between tenofovir and cLEE emerging within the first 2 years after drug initiation. This novel tenofovir-cLEE signal should be further investigated.

HIV-1 Transmission During Recent Infection and During Treatment Interruptions as Major Drivers of New Infections in the Swiss HIV Cohort Study

BACKGROUND

Reducing the fraction of transmissions during recent human immunodeficiency virus (HIV) infection is essential for the population-level success of "treatment as prevention".

METHODS

A phylogenetic tree was constructed with 19 604 Swiss sequences and 90 994 non-Swiss background sequences. Swiss transmission pairs were identified using 104 combinations of genetic distance (1%-2.5%) and bootstrap (50%-100%) thresholds, to examine the effect of those criteria. Monophyletic pairs were classified as recent or chronic transmission based on the time interval between estimated seroconversion dates. Logistic regression with adjustment for clinical and demographic characteristics was used to identify risk factors associated with transmission during recent or chronic infection.

FINDINGS

Seroconversion dates were estimated for 4079 patients on the phylogeny, and comprised between 71 (distance, 1%; bootstrap, 100%) to 378 transmission pairs (distance, 2.5%; bootstrap, 50%). We found that 43.7% (range, 41%-56%) of the transmissions occurred during the first year of infection. Stricter phylogenetic definition of transmission pairs was associated with higher recent-phase transmission fraction. Chronic-phase viral load area under the curve (adjusted odds ratio, 3; 95% confidence interval, 1.64-5.48) and time to antiretroviral therapy (ART) start (adjusted odds ratio 1.4/y; 1.11-1.77) were associated with chronic-phase transmission as opposed to recent transmission. Importantly, at least 14% of the chronic-phase transmission events occurred after the transmitter had interrupted ART.

CONCLUSIONS

We demonstrate a high fraction of transmission during recent HIV infection but also chronic transmissions after interruption of ART in Switzerland. Both represent key issues for treatment as prevention and underline the importance of early diagnosis and of early and continuous treatment.

High hepatic and extrahepatic mortality and low treatment uptake in HCV-coinfected persons in the Swiss HIV cohort study between 2001 and 2013

BACKGROUND & AIMS

The landscape of HCV treatments is changing dramatically. At the beginning of this new era, we highlight the challenges for HCV therapy by assessing the long-term epidemiological trends in treatment uptake, efficacy and mortality among HIV/HCV-coinfected people since the availability of HCV therapy.

METHODS

We included all SHCS participants with detectable HCV RNA between 2001 and 2013. To identify predictors for treatment uptake uni- and multivariable Poisson regression models were applied. We further used survival analyses with Kaplan-Meier curves and Cox regression with drop-out as competing risk.

RESULTS

Of 12,401 participants 2107 (17%) were HCV RNA positive. Of those, 636 (30%) started treatment with an incidence of 5.8/100 person years (PY) (95% CI 5.3-6.2). Sustained virological response (SVR) with pegylated interferon/ribavirin was achieved in 50% of treated patients, representing 15% of all participants with replicating HCV-infection. 344 of 2107 (16%) HCV RNA positive persons died, 59% from extrahepatic causes. Mortality/100 PY was 2.9 (95% CI 2.6-3.2) in untreated patients, 1.3 (1.0-1.8) in those treated with failure, and 0.6 (0.4-1.0) in patients with SVR. In 2013, 869/2107 (41%) participants remained HCV RNA positive.

CONCLUSIONS

Over the last 13 years HCV treatment uptake was low and by the end of 2013, a large number of persons remain to be treated. Mortality was high, particularly in untreated patients, and mainly due to non-liver-related causes. Accordingly, in HIV/HCV-coinfected patients, integrative care including the diagnosis and therapy of somatic and psychiatric disorders is important to achieve mortality rates similar to HIV-monoinfected patients.

Ribavirin Concentrations Do Not Predict Sustained Virological Response in HIV/HCV-Coinfected Patients Treated with Ribavirin and Pegylated Interferon in the Swiss HIV Cohort Study

Background

Ribavirin (RBV) is an essential component of most current hepatitis C (HCV) treatment regimens and still standard of care in the combination with pegylated interferon (pegIFN) to treat chronic HCV in resource limited settings. Study results in HIV/HCV-coinfected patients are contradicting as to whether RBV concentration correlates with sustained virological response (SVR).

Methods

We included 262 HCV treatment naïve HIV/HCV-coinfected Swiss HIV Cohort Study (SHCS) participants treated with RBV and pegIFN between 01.01.2001-01.01.2010, 134 with HCV genotype (GT) 1/4, and 128 with GT 2/3 infections. RBV levels were measured retrospectively in stored plasma samples obtained between HCV treatment week 4 and end of therapy. Uni- and multivariable logistic regression analyses were used to evaluate the association between RBV concentration and SVR in GT 1/4 and GT 2/3 infections. The analyses were repeated stratified by treatment phase (week 4-12, 13-24, >24) and IL28B genotype (CC versus CT/TT).

Results

SVR rates were 35.1% in GT 1/4 and 70.3% in GT 2/3 infections. Overall, median RBV concentration was 2.0 mg/L in GT 1/4, and 1.9 mg/L in GT 2/3, and did not change significantly across treatment phases. Patients with SVR had similar RBV concentrations compared to patients without SVR in both HCV genotype groups. SVR was not associated with RBV levels ≥2.0 mg/L (GT 1/4, OR 1.19 [0.5-2.86]; GT 2/3, 1.94 [0.78-4.80]) and ≥2.5 mg/L (GT 1/4, 1.56 [0.64-3.84]; GT 2/3 2.72 [0.85-8.73]), regardless of treatment phase, and IL28B genotype.

Conclusion

In HIV/HCV-coinfected patients treated with pegIFN/RBV, therapeutic drug monitoring of RBV concentrations does not enhance the chance of HCV cure, regardless of HCV genotype, treatment phase and IL28B genotype.

Strong Impact of Smoking on Multimorbidity and Cardiovascular Risk Among Human Immunodeficiency Virus-Infected Individuals in Comparison With the General Population

AIDS-associated morbidity has diminished due to excellent viral control. Multimorbidity are more prevalent and incident in Swiss HIV-positive persons compared to HIV-negative controls. However, smoking, but not HIV status, had a strong impact on cardiovascular risk and multimorbidity.

Background. Although acquired immune deficiency syndrome-associated morbidity has diminished due to excellent viral control, multimorbidity may be increasing among human immunodeficiency virus (HIV)-infected persons compared with the general population.

Methods. We assessed the prevalence of comorbidities and multimorbidity in participants of the Swiss HIV Cohort Study (SHCS) compared with the population-based CoLaus study and the primary care-based FIRE (Family Medicine ICPC-Research using Electronic Medical Records) records. The incidence of the respective endpoints were assessed among SHCS and CoLaus participants. Poisson regression models were adjusted for age, sex, body mass index, and smoking.

Results. Overall, 74 291 participants contributed data to prevalence analyses (3230 HIV-infected; 71 061 controls). In CoLaus, FIRE, and SHCS, multimorbidity was present among 26%, 13%, and 27% of participants. Compared with nonsmoking individuals from CoLaus, the incidence of cardiovascular disease was elevated among smoking individuals but independent of HIV status (HIV-negative smoking: incidence rate ratio [IRR] = 1.7, 95% confidence interval [CI] = 1.2–2.5; HIV-positive smoking: IRR = 1.7, 95% CI = 1.1–2.6; HIV-positive nonsmoking: IRR = 0.79, 95% CI = 0.44–1.4). Compared with nonsmoking HIV-negative persons, multivariable Poisson regression identified associations of HIV infection with hypertension (nonsmoking: IRR = 1.9, 95% CI = 1.5–2.4; smoking: IRR = 2.0, 95% CI = 1.6–2.4), kidney (nonsmoking: IRR = 2.7, 95% CI = 1.9–3.8; smoking: IRR = 2.6, 95% CI = 1.9–3.6), and liver disease (nonsmoking: IRR = 1.8, 95% CI = 1.4–2.4; smoking: IRR = 1.7, 95% CI = 1.4–2.2). No evidence was found for an association of HIV-infection or smoking with diabetes mellitus.

Conclusions. Multimorbidity is more prevalent and incident in HIV-positive compared with HIV-negative individuals. Smoking, but not HIV status, has a strong impact on cardiovascular risk and multimorbidity.

Protease inhibitors to treat hepatitis C in the Swiss HIV Cohort Study: high efficacy but low treatment uptake

OBJECTIVES

Direct-acting antiviral agents (DAAs) have become the standard of care for the treatment of chronic hepatitis C virus (HCV) infection. We aimed to assess treatment uptake and efficacy in routine clinical settings among HIV/HCV coinfected patients after the introduction of the first generation DAAs.

METHODS

Data on all Swiss HIV Cohort Study (SHCS) participants starting HCV protease inhibitor (PI) treatment between September 2011 and August 2013 were collected prospectively. The uptake and efficacy of HCV therapy were compared with those in the time period before the availability of PIs.

RESULTS

Upon approval of PI treatment in Switzerland in September 2011, 516 SHCS participants had chronic HCV genotype 1 infection. Of these, 57 (11%) started HCV treatment during the following 2 years with either telaprevir, faldaprevir or boceprevir. Twenty-seven (47%) patients were treatment-naïve, nine (16%) were patients with relapse and 21 (37%) were partial or null responders. Twenty-nine (57%) had advanced fibrosis and 15 (29%) had cirrhosis. End-of-treatment virological response was 84% in treatment-naïve patients, 88% in patients with relapse and 62% in previous nonresponders. Sustained virological response was 78%, 86% and 40% in treatment-naïve patients, patients with relapse and nonresponders, respectively. Treatment uptake was similar before (3.8 per 100 patient-years) and after (6.1 per 100 patient-years) the introduction of PIs, while treatment efficacy increased considerably after the introduction of PIs.

CONCLUSIONS

The introduction of PI-based HCV treatment in HIV/HCV-coinfected patients improved virological response rates, while treatment uptake remained low. Therefore, the introduction of PIs into the clinical routine was beneficial at the individual level, but had only a modest effect on the burden of HCV infection at the population level.

Increases in Condomless Sex in the Swiss HIV Cohort Study

Condomless sex is a key driver of sexually transmitted diseases. In this study, we assess the long-term changes (2000-2013) of the occurrence of condomless sex among human immunodeficiency virus (HIV)-infected individuals enrolled in the Swiss HIV Cohort study. The frequencies with which HIV-infected individuals reported condomless sex were either stable or only weakly increasing for 2000-2008. For 2008-2013, these rates increased significantly for stable relationships among heterosexuals and men who have sex with men (MSM) and for occasional relationships among MSM. Our results highlight the increasing public health challenge posed by condomless sex and show that condomless sex has been increasing even in the most recent years.

Incident Hepatitis C Virus Infections in the Swiss HIV Cohort Study: Changes in Treatment Uptake and Outcomes Between 1991 and 2013

Background.  The hepatitis C virus (HCV) epidemic is evolving rapidly in patients infected with human immunodeficiency virus (HIV). We aimed to describe changes in treatment uptake and outcomes of incident HCV infections before and after 2006, the time-point at which major changes in HCV epidemic became apparent. Methods.  We included all adults with an incident HCV infection before June 2012 in the Swiss HIV Cohort Study, a prospective nationwide representative cohort of individuals infected with HIV. We assessed the following outcomes by time period: the proportion of patients starting an HCV therapy, the proportion of treated patients achieving a sustained virological response (SVR), and the proportion of patients with persistent HCV infection during follow-up. Results.  Of 193 patients with an HCV seroconversion, 106 were diagnosed before and 87 after January 2006. The proportion of men who have sex with men increased from 24% before to 85% after 2006 (P < .001). Hepatitis C virus treatment uptake increased from 33% before 2006 to 77% after 2006 (P < .001). Treatment was started during early infection in 22% of patients before and 91% after 2006 (P < .001). An SVR was achieved in 78% and 29% (P = .01) of patients treated during early and chronic HCV infection. The probability of having a detectable viral load 5 years after diagnosis was 0.67 (95% confidence interval [CI], 0.58-0.77) in the group diagnosed before 2006 and 0.24 (95% CI, 0.16-0.35) in the other group (P < .001). Conclusions.  In recent years, increased uptake and earlier initiation of HCV therapy among patients with incident infections significantly reduced the proportion of patients with replicating HCV.

[HIV-associated non-AIDS conditions]

Antiretroviral therapy (ART) has improved quality of life and increased life expectancy of HIV-infected individuals. Opportunistic diseases are less common, and mortality has declined. Consequently, patterns of mortality and morbidity are changing among the HIV-positive population. The focus of care has shifted to ART-related problems and to various non-AIDS diseases. Such comorbidities, often occurring sequentially or concurrently, may be the consequences of long term ART toxicity, a state of chronic inflammation due to HIV infection, lifestyle-related risks for disease, and aging. The emergence of non-AIDS related conditions highlights the important role of primary care physicians, especially of those with extensive experience in HIV management.

Obesity Trends and Body Mass Index Changes After Starting Antiretroviral Treatment: The Swiss HIV Cohort Study

BACKGROUND

The factors that contribute to increasing obesity rates in human immunodeficiency virus (HIV)-positive persons and to body mass index (BMI) increase that typically occurs after starting antiretroviral therapy (ART) are incompletely characterized.

METHODS

We describe BMI trends in the entire Swiss HIV Cohort Study (SHCS) population and investigate the effects of demographics, HIV-related factors, and ART on BMI change in participants with data available before and 4 years after first starting ART.

RESULTS

In the SHCS, overweight/obesity prevalence increased from 13% in 1990 (n = 1641) to 38% in 2012 (n = 8150). In the participants starting ART (n = 1601), mean BMI increase was 0.92 kg/m(2) per year (95% confidence interval, .83-1.0) during year 0-1 and 0.31 kg/m(2) per year (0.29-0.34) during years 1-4. In multivariable analyses, annualized BMI change during year 0-1 was associated with older age (0.15 [0.06-0.24] kg/m(2)) and CD4 nadir <199 cells/µL compared to nadir >350 (P < .001). Annualized BMI change during years 1-4 was associated with CD4 nadir <100 cells/µL compared to nadir >350 (P = .001) and black compared to white ethnicity (0.28 [0.16-0.37] kg/m(2)). Individual ART combinations differed little in their contribution to BMI change.

CONCLUSIONS

Increasing obesity rates in the SHCS over time occurred at the same time as aging of the SHCS population, demographic changes, earlier ART start, and increasingly widespread ART coverage. Body mass index increase after ART start was typically biphasic, the BMI increase in year 0-1 being as large as the increase in years 1-4 combined. The effect of ART regimen on BMI change was limited.

Higher risk of incident hepatitis C virus coinfection among men who have sex with men, in whom the HIV genetic bottleneck at transmission was wide

BACKGROUND

High-risk sexual behaviors have been suggested as drivers of the recent dramatic increase of sexually transmitted hepatitis C virus (HCV) among human immunodeficiency virus (HIV)-infected men who have sex with men (MSM).

METHODS

We assessed the association between the genetic bottleneck of HIV at transmission and the prevalence and incidence of HCV coinfection in HIV-infected MSM from the Swiss HIV Cohort Study (SHCS). As a proxy for the width of the transmission bottleneck, we used the fraction of ambiguous nucleotides detected by genotypic resistance tests sampled during early HIV infection. We defined a broad bottleneck as a fraction of ambiguous nucleotides exceeding a previously established threshold (0.5%).

RESULTS

From the SHCS, we identified 671 MSM with available results of HCV serologic tests and with an HIV genotypic resistance test performed during early HIV infection. Of those, 161 (24.0%) exhibited a broad HIV transmission bottleneck, 38 (5.7%) had at least 1 positive HCV test result, and 26 (3.9%) had an incident HCV infection. Individuals with broad HIV transmission bottlenecks exhibited a 2-fold higher odds of having ever experienced an HCV coinfection (odds ratio, 2.2 [95% confidence interval {CI}, 1.1-4.3]) and a 3-fold higher hazard of having an incident HCV infection (hazard ratio, 3.0 [95% CI, 1.4-6.6]) than individuals with narrow HIV transmission bottlenecks.

CONCLUSIONS

Our results indicate that the currently occurring sexual spread of HCV is focused on MSM who are prone to exhibit broad HIV transmission bottlenecks. This is consistent with an important role of high-risk behavior and mucosal barrier impairment in the transmission of HCV among MSM.