Publications by authors named "Greenwald Z"

Background: Supervised consumption service (SCS) use among people who inject drugs may reduce acute care utilization; however, prior studies have been limited by self-reported outcomes and dichotomous exposures.

Methods: We conducted a prospective cohort study using linked questionnaire and health administrative data among people who inject drugs in Toronto, Canada (2018-2020). Baseline SCS use frequency was defined by a participant's self-reported proportion of injections performed at an SCS over the past six months: "all/most" (≥75 %), "some" (26-74 %), "few" (1-25 %), or "none" (0 %).

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Objectives: Health administrative data can be used to improve the health of people who inject drugs by informing public health surveillance and program planning, monitoring, and evaluation. However, methodological gaps in the use of these data persist due to challenges in accurately identifying injection drug use (IDU) at the population level. In this study, we validated case-ascertainment algorithms for identifying people who inject drugs using health administrative data in Ontario, Canada.

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Background: Despite high burden of Hepatitis C (HCV) among people who inject drugs, significant barriers to care persist. The aim of this study was to evaluate the provision of rapid, low-barrier point-of-care (POC) HCV RNA testing and linkage to care among clients of a supervised consumption service (SCS) located within a community health centre in Toronto, Canada. Secondary aims included measuring HCV RNA prevalence at baseline, HCV incidence during follow-up and exploring factors associated with HCV RNA positivity and treatment uptake.

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Despite the availability of publicly funded hepatitis C (HCV) treatment in Canada, treatment gaps persist, particularly among people who inject drugs. We estimate correlates of HCV care cascade engagement (testing, diagnosis, and treatment) among people who inject drugs in Toronto, Canada and examine the effect of accessing differing supervised consumption service (SCS) models on self-reported HCV testing and treatment. This is a cross-sectional baseline analysis of 701 people who inject drugs surveyed in the Toronto, Ontario integrated Supervised Injection Services (OiSIS-Toronto) study between November 2018 and March 2020.

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Objectives: Use of illicit substances during sex (chemsex) may increase transmission of HIV and other STIs. Pre-exposure prophylaxis (PrEP) is highly effective at preventing HIV transmission, providing an important prevention tool for those who practise chemsex. However, it does not prevent acquisition of other STIs.

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Background: Apart from the Epstein-Barr virus (EBV), the etiology of the hematologic malignancy Hodgkin lymphoma (HL) is not well defined. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are associated with some lymphoproliferative diseases with similarities to HL.

Methods: We performed a systematic review and meta-analysis, by searching Embase, MEDLINE, and Web of Science databases on March 9, 2021, for studies reporting a measure of association for HBV and HL or HCV and HL.

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Introduction: Chemsex among gay, bisexual and other men who have sex with men (gbMSM) has raised public health concerns because of its association with sexual behaviours that can increase transmission of sexually transmitted infections, including HIV. Pre-exposure prophylaxis (PrEP) is highly effective at blocking HIV acquisition, addressing important prevention needs among individuals practicing chemsex. This study aims to improve our understanding of chemsex practices and PrEP trajectories of gbMSM and transgender women consulting for PrEP.

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The Ontario Integrated Supervised Injection Services cohort in Toronto, Canada (OiSIS-Toronto) is an open prospective cohort of people who inject drugs (PWID). OiSIS-Toronto was established to evaluate the impacts of supervised consumption services (SCS) integrated within three community health agencies on health status and service use. The cohort includes PWID who do and do not use SCS, recruited via self-referral, snowball sampling, and community/street outreach.

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Hepatitis C virus (HCV) elimination has evolved into a coordinated global effort. Canada, with more than 250,000 chronically infected individuals, is among the countries leading this effort. The 9th Canadian Symposium on HCV, held in February 2020, thus established and addressed its theme, 'advances in HCV research and treatment towards elimination', by gathering together basic scientists, clinicians, epidemiologists, social scientists, and community members interested in HCV research in Canada.

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There is uncertainty regarding the potential virologic outcome associated with a change in antiretroviral therapy (ARV) among PLHIV who had previous documented virologic failure or who have been exposure to mono/dual nucleoside reverse transcriptase inhibitors (NRTI) therapy. The objective was to measure the potential impact of exposure to previous virologic failure or mono/dual NRTI regimen on virologic outcome of PLHIV following a switch to dolutegravir with 2 NRTIs from a viremia suppressive ARV therapy.Data from the Quebec HIV Cohort including 10219 PLHIV were collected through routine clinical care at 4 clinical sites in Montreal, Canada.

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Background: Switching antiretroviral regimens when human immunodeficiency virus (HIV) viremia is controlled for a new regimen is challenging when there is the potential for prior nucleoside reverse-transcriptase inhibitor (NRTI) resistance. The objective was to study virologic outcomes after switching to dolutegravir compared with remaining on a boosted protease inhibitor (protease inhibitor/ritonavir [PI/r]) regimen in people with HIV (PWH) with prior documented virologic failure and/or exposure to mono/dual NRTIs.

Methods: We used the Quebec HIV Cohort including 10 219 PWH whose data were collected at 4 sites in Montreal, Canada.

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Background: Reducing HIV transmission using pre-exposure prophylaxis (PrEP) requires focussing on individuals at high acquisition risk, such as men who have sex with men with a history of nonoccupational post-exposure prophylaxis (nPEP). This study aims to characterize longitudinal trends in PrEP uptake and its determinants among nPEP users in Montréal.

Methods: Eligible attendees at Clinique médicale l'Actuel were recruited prospectively starting in October 2000 (nPEP) and January 2013 (PrEP).

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Background: Many immigrants are susceptible to varicella on arrival to Canada because of different transmission dynamics in their countries of origin and scarcity of vaccination. Universal childhood vaccination programmes decrease varicella incidence rates through herd immunity, but the accumulating number of susceptible adult immigrants could remain at risk for severe varicella. Our aim was to describe the epidemiology of varicella among immigrants and non-immigrants before and after childhood varicella vaccination.

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Purpose: The was established to monitor the uptake, effectiveness, safety and changes in sexual risk behaviours among individuals receiving pre-exposure prophylaxis (PrEP) for the prevention of HIV. This prospective dynamic cohort is based at Clinique médicale l'Actuel, a large sexual health clinic located in Montreal, Canada.

Participants: Since the cohort inception in January of 2013 through June 2018, 2156 individuals consulted for PrEP as participants in the l'Actuel PrEP Cohort.

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Objective: Identifying human papillomavirus (HPV) vaccination motivators and barriers among adults could lead to new approaches to improve HPV vaccination rates in non-pediatric populations. This Canadian survey aimed to assess current knowledge of, attitudes towards, and barriers to the HPV vaccine among the general public.

Methods: An online panel was used to survey HPV unvaccinated women (n = 802) and vaccinated women (n = 250) 18 to 45 years old, as well as 18- to 26-year-old men (n = 200), in May and June 2016.

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Population-based registries are increasingly used in cancer research. In such studies, cancer-specific mortality or survival is frequently used as the primary outcome. To determine whether a putative cancer was part of the causal chain of events leading to death, cancer registries primarily rely on death certificates.

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Objective: Physicians are the sole prescribers of the human papillomavirus (HPV) vaccine for adults in Canada. This survey of Canadian physicians aimed to explore knowledge, barriers, and preventive practices regarding HPV vaccination.

Method: A survey of general practitioners (GPs) (n = 337) and obstetrician/gynaecologists (OB/GYNs) (n = 81) was conducted in May and June 2016 using an online panel.

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Unlabelled: Tuberculosis (TB) and HIV constitute the main burden of infectious diseases worldwide. Imprisonment is an important risk factor for contracting TB, especially among those living with HIV. This systematic review summarizes the available data on the prevalence of TB among HIV-positive prisoners; which may support improved targeted TB/HIV prevention plans.

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Since 2003, there has been a resurgence of lymphogranuloma venereum (LGV), a variant of Chlamydia trachomatis (CT), among men who have sex with men (MSM) in several urban areas of Europe and North America. LGV infection occurs most often at anal sites causing proctitis. Urethral and oropharyngeal infections are rare.

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Purpose: In Brazil, access to breast cancer screening outside of urban centers is limited. This study aims to describe the coverage and performance of a breast cancer screening program implemented with Mobile Screening Units (MSU) in northern São Paulo state.

Methods: This is a retrospective cohort study of a population-based mammography program targeting women ages 40-69 in 108 municipalities from 12/2010 to 07/2015.

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Objective: Use of preexposure prophylaxis (PrEP) for HIV raises concerns about sexually transmitted infection (STI) incidence because of decreased condom use among MSM. This study examines whether PrEP is associated with STIs in the 12 months following PrEP prescription relative to the 12 months prior to PrEP and if STI rates are higher among PrEP users relative to individuals receiving postexposure prophylaxis (PEP).

Design: Retrospective cohort study including PrEP users with more than 12 months of follow-up before PrEP prescription and individuals receiving PEP from 2010 to 2015 at Clinique l'Actuel (Montréal, Canada).

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Purpose: Clinical trials studying immune checkpoint inhibitors exclude patients on corticosteroids, due to the hypothesis that corticosteroids may antagonize immunotherapy. We performed a systematic review of the literature looking at the clinical outcomes of cancer patients treated with immune checkpoint inhibitors and concomitant corticosteroids.

Methods: The following databases were searched for relevant studies: MEDLINE, Embase Classic+Embase, BIOSIS Previews, the Cochrane Database of Systematic Reviews, the CENTRAL Registry of Controlled Trials, Web of Science and Scopus.

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