Heterogeneity in testing, diagnosis and outcome in SARS-CoV-2 infection across outbreak settings in the Greater Toronto Area, Canada: an observational study

Abstract

Large urban centres such as the Greater Toronto Area (GTA) shouldered the highest burden. 2 By May 20, the 16 490 cases detected in the GTA's population of 6.8 million 3 represented 21% of cases in the country, more than two-thirds of cases in Ontario and a diagnosis per capita rate 1.5 times that of Ontario overall. 1,2 As in past outbreaks of respiratory virus, 4 congregate settings were disproportionately affected by COVID-19 globally 5 and across Canada. 6-9 Settings such as long-term care homes and homeless shelters were vulnerable partly owing to design barriers (e.g., shared living quarters and communal spaces) to physical distancing, and underresourcing of infection prevention and control measures. 10-14 Lessons from past epidemics suggest that disproportionate risks across settings contribute to the spread and outcomes of infection. 15 Thus, a key feature of an epidemic response is

Prevalence of SARS-CoV-2 infection among people experiencing homelessness in Toronto during the first wave of the COVID-19 pandemic

“…Furthermore, the number of homeless persons living in outdoor encampments has risen during the pandemic, raising questions about whether the risk for SARS-CoV-2 infection in encampments is higher or lower than in shelters. Earlier studies of SARS-CoV-2 infection rates across various outbreak settings in the Greater Toronto Area have found a sharp shift from travel-related and community-related cases to congregate-related cases, especially in long-term care (LTC) homes between January 23 and May 20, 2020 (Wang et al, 2020 ). In particular, the epidemic curve of LTC homes peaked in early April.…”

SARS-CoV-2 Control on a Large Urban College Campus Without Mass Testing

“…Students who were selected but were experiencing symptoms were removed from the asymptomatic sample and sent to SHS for testing. Given evidence that SARS-CoV-2 infection prevalence varies by region, and that spread differs in congregate versus non-congregate settings 2-4 , the CMRO considered student subgroups defined by where they were coming from: 1) residents of the Western Pennsylvania region; 2) in-state students from outside of Western Pennsylvania; 3) out-of-state domestic students from other US states; and 4) international students. Each group was further divided into on-campus and off-campus residents, resulting in 8 groups overall.…”

Support for self-isolation is critical in covid-19 response

“…The highest covid-19 mortality has been observed in facility based outbreaks, including in long term care facilities, retirement homes, and homeless shelters 11415. Staff in long term care and similar occupations are low paid, often on zero hours contracts, and typically share the prevalence patterns of the communities at greatest risk of covid-19 15…”

“…1 14 15 Staff in long term care and similar occupations are low paid, often on zero hours contracts, and typically share the prevalence patterns of the communities at greatest risk of covid-19. 15 Since the landmark principles of a population screening test were first set out by Wilson and Jungner in 1968, it has been accepted that the usefulness of screening tests is determined by the effectiveness of the intervention they trigger. 16 What interventions can justify covid-19 screening tests, given the barriers to self-isolation faced by those at highest risk of a positive result?…”