Circulating HBV RNA and Hepatitis B Core-Related Antigen Trajectories in Persons With HIV/HBV Coinfection and Hepatitis B Surface Antigen Loss During Tenofovir Therapy.

Background: We evaluated long-term trajectories of circulating hepatitis B virus (HBV) RNA and hepatitis B core-related antigen (HBcrAg) in persons with and without hepatitis B surface antigen (HBsAg) loss during tenofovir therapy in the Swiss HIV Cohort Study.

Methods: We included 29 persons with HIV with HBsAg loss and 29 matched persons with HIV without HBsAg loss. We compared HBV RNA and HBcrAg decline and assessed the cumulative proportions with undetectable HBV RNA and HBcrAg levels during tenofovir therapy using Kaplan-Meier estimates.

Long-term quantitative hepatitis B surface antigen (HBsAg) trajectories in persons with and without HBsAg loss on tenofovir-containing antiretroviral therapy.

Objectives: Improving the understanding of the patterns of quantitative hepatitis B surface antigen (qHBsAg) trajectories associated with HBsAg loss is important in light of novel anti-hepatitis B virus agents being developed. We evaluated long-term qHBsAg trajectories in persons with HIV and HBV during tenofovir-containing antiretroviral therapy in the Swiss HIV Cohort Study.

Methods: We included 29 participants with and 29 without HBsAg loss, defined as qHBsAg <0.

Sexual Behaviour and STI Incidence in Sexually Active MSM Living With HIV in Times of COVID-19.

Despite decreased numbers of sexual partners, the COVID-19 pandemic had limited impact on the prevalence of attending private sex parties, traveling for sex within Switzerland, and practicing chemsex in men with HIV who have sex with men. COVID-19 risk perception was low, and STI-diagnosis incidence rates remained stable over time.

Mental Health, ART Adherence, and Viral Suppression Among Adolescents and Adults Living with HIV in South Africa: A Cohort Study.

We followed adolescents and adults living with HIV aged older than 15 years who enrolled in a South African private-sector HIV programme to examine adherence and viral non-suppression (viral load > 400 copies/mL) of participants with (20,743, 38%) and without (33,635, 62%) mental health diagnoses. Mental health diagnoses were associated with unfavourable adherence patterns. The risk of viral non-suppression was higher among patients with organic mental disorders [adjusted risk ratio (aRR) 1.

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.

Unsupervised machine learning predicts future sexual behaviour and sexually transmitted infections among HIV-positive men who have sex with men.

Machine learning is increasingly introduced into medical fields, yet there is limited evidence for its benefit over more commonly used statistical methods in epidemiological studies. We introduce an unsupervised machine learning framework for longitudinal features and evaluate it using sexual behaviour data from the last 20 years from over 3'700 participants in the Swiss HIV Cohort Study (SHCS). We use hierarchical clustering to find subgroups of men who have sex with men in the SHCS with similar sexual behaviour up to May 2017, and apply regression to test whether these clusters enhance predictions of sexual behaviour or sexually transmitted diseases (STIs) after May 2017 beyond what can be predicted with conventional parameters.

Extending outbreak investigation with machine learning and graph theory: Benefits of new tools with application to a nosocomial outbreak of a multidrug-resistant organism.

Objective: From January 1, 2018, until July 31, 2020, our hospital network experienced an outbreak of vancomycin-resistant enterococci (VRE). The goal of our study was to improve existing processes by applying machine-learning and graph-theoretical methods to a nosocomial outbreak investigation.

Methods: We assembled medical records generated during the first 2 years of the outbreak period (January 2018 through December 2019).

An Approach to Quantifying the Interaction between Behavioral and Transmission Clusters.

We hypothesize that patterns of sexual behavior play a role in the conformation of transmission networks, i.e., the way you behave might influence whom you have sex with.

Sustained Effect on Hepatitis C Elimination Among Men Who Have Sex With Men in the Swiss HIV Cohort Study: A Systematic Re-Screening for Hepatitis C RNA Two Years Following a Nation-Wide Elimination Program.

Background: The Swiss HCVree Trial (NCT02785666) was conducted in 2015-2017 with the goal of implementing a population-based systematic hepatitis C virus (HCV) micro-elimination program among men who have sex with men (MSM) with human immunodeficiency virus (HIV) enrolled in the Swiss HIV Cohort Study (SHCS). The trial led to a 91% and 77% decline of HCV prevalence and incidence, respectively. The long-term effect of this HCV micro-elimination program is yet to be explored.

Assessing the drivers of syphilis among men who have sex with men in Switzerland reveals a key impact of screening frequency: A modelling study.

Over the last decade, syphilis diagnoses among men-who-have-sex-with-men (MSM) have strongly increased in Europe. Understanding the drivers of the ongoing epidemic may aid to curb transmissions. In order to identify the drivers of syphilis transmission in MSM in Switzerland between 2006 and 2017 as well as the effect of potential interventions, we set up an epidemiological model stratified by syphilis stage, HIV-diagnosis, and behavioral factors to account for syphilis infectiousness and risk for transmission.

Identifying the drivers of multidrug-resistant Klebsiella pneumoniae at a European level.

Beta-lactam- and in particular carbapenem-resistant Enterobacteriaceae represent a major public health threat. Despite strong variation of resistance across geographical settings, there is limited understanding of the underlying drivers. To assess these drivers, we developed a transmission model of cephalosporin- and carbapenem-resistant Klebsiella pneumoniae.

HCV Genetic Diversity Can Be Used to Infer Infection Recency and Time since Infection.

HIV-1 genetic diversity can be used to infer time since infection (TSI) and infection recency. We adapted this approach for HCV and identified genomic regions with informative diversity. We included 72 HCV/HIV-1 coinfected participants of the Swiss HIV Cohort Study, for whom reliable estimates of infection date and viral sequences were available.

A Treatment-as-Prevention Trial to Eliminate Hepatitis C Among Men Who Have Sex With Men Living With Human Immunodeficiency Virus (HIV) in the Swiss HIV Cohort Study.

Background: In 2016, the World Health Organization (WHO) introduced global targets for the elimination of hepatitis C virus (HCV) by 2030. We conducted a nationwide HCV micro-elimination program among men who have sex with men (MSM) living with human immunodeficiency virus (HIV) from the Swiss HIV Cohort Study (SHCS) to test whether the WHO goals are achievable in this population.

Methods: During phase A (10/2015-06/2016), we performed a population-based and systematic screening for HCV-RNA among MSM from the SHCS.

Self-reported Neurocognitive Impairment in People Living With Human Immunodeficiency Virus (HIV): Characterizing Clusters of Patients With Similar Changes in Self-reported Neurocognitive Impairment, 2013-2017, in the Swiss HIV Cohort Study.

Background: Self-reported neurocognitive impairment (SRNI) in people living with human immunodeficiency virus type 1 (HIV-1) infection is frequent. We use longitudinal information on SRNI in the Swiss HIV Cohort Study (SHCS) to identify and characterize groups of patients with persisting SRNI over time.

Methods: We included all SHCS patients who were assessed for SRNI during at least 5 visits spanning at least 2.

Can Australia Reach the World Health Organization Hepatitis C Elimination Goal by 2025 Among Human Immunodeficiency Virus-positive Gay and Bisexual Men?

Background: Human immunodeficiency virus (HIV)-positive gay and bisexual men (GBM) in Australia are well engaged in care. The World Health Organization's (WHO) hepatitis C virus (HCV) elimination target of an 80% reduction in incidence by 2030 may be reachable ahead of time in this population.

Methods: We predicted the effect of treatment and behavioral changes on HCV incidence among HIV-positive GBM up to 2025 using a HCV transmission model parameterized with Australian data.

Changing Trends in International Versus Domestic HCV Transmission in HIV-Positive Men Who Have Sex With Men: A Perspective for the Direct-Acting Antiviral Scale-Up Era.

Background: Scale-up of direct-acting antiviral therapy is expected to abate hepatitis C virus (HCV) incidence among human immunodeficiency virus (HIV)-positive men who have sex with men (MSM). International transmission could influence this process. We classified HCV infections in HIV-positive MSM as either domestically or internationally acquired, and estimated how this classification changed over time.

Impact of Direct-Acting Antivirals on the Burden of HCV Infection Among Persons Who Inject Drugs and Men Who Have Sex With Men in the Swiss HIV Cohort Study.

In the Swiss HIV Cohort Study, the number of people who inject drugs with replicating hepatitis C virus (HCV) infection decreased substantially after the introduction of direct-acting antivirals (DAAs). Among men who have sex with men, the increase in DAA uptake and efficacy was counterbalanced by frequent incident HCV infections.

The Effect of Monitoring Viral Load and Tracing Patients Lost to Follow-up on the Course of the HIV Epidemic in Malawi: A Mathematical Model.

Background: Antiretroviral therapy (ART) reduces HIV transmission, but treated patients may again become infectious. We used a mathematical model to determine whether ART as prevention is more effective if viral load (VL) is routinely monitored and patients lost to follow-up (LTFU) traced.

Methods: We simulated ART cohorts to parameterize a deterministic transmission model calibrated to Malawi.

Understanding and Addressing Hepatitis C Virus Reinfection Among Men Who Have Sex with Men.

Hepatitis C virus reinfection rates among men who have sex with men are high. Factors associated with infection point to varied sexual and drug-related risks that could be targeted for interventions to prevent infection/reinfection. Modeling indicates that tackling increasing incidence and high reinfection rates requires high levels of hepatitis C virus treatment combined with behavioral interventions.

Hepatitis C virus transmission among human immunodeficiency virus-infected men who have sex with men: Modeling the effect of behavioral and treatment interventions.

Unlabelled: The incidence of hepatitis C virus (HCV) infections among human immunodeficiency virus (HIV)-infected men who have sex with men has increased in recent years and is associated with high-risk sexual behavior. Behavioral interventions that target high-risk behavior associated with HCV transmission and treatment with direct-acting antivirals may prevent further HCV infections. We predicted the effect of behavioral and treatment interventions on HCV incidence and prevalence among HIV-infected men who have sex with men up to 2030 using a HCV transmission model parameterized with data from the Swiss HIV Cohort Study.

Adherence to Antiretroviral Therapy During and After Pregnancy: Cohort Study on Women Receiving Care in Malawi's Option B+ Program.

Background: Adherence to antiretroviral therapy (ART) is crucial to preventing mother-to-child transmission of human immunodeficiency virus (HIV) and ensuring the long-term effectiveness of ART, yet data are sparse from African routine care programs on maternal adherence to triple ART.

Methods: We analyzed data from women who started ART at 13 large health facilities in Malawi between September 2011 and October 2013. We defined adherence as the percentage of days "covered" by pharmacy claims.

Tuberculosis in Cape Town: An age-structured transmission model.

Background: Tuberculosis (TB) is the leading cause of death in South Africa. The burden of disease varies by age, with peaks in TB notification rates in the HIV-negative population at ages 0-5, 20-24, and 45-49 years. There is little variation between age groups in the rates in the HIV-positive population.

The need for second-line antiretroviral therapy in adults in sub-Saharan Africa up to 2030: a mathematical modelling study.

Background: The number of patients in need of second-line antiretroviral drugs is increasing in sub-Saharan Africa. We aimed to project the need of second-line antiretroviral therapy in adults in sub-Saharan Africa up to 2030.

Methods: We developed a simulation model for HIV and applied it to each sub-Saharan African country.