Multifaceted strategies for the control of COVID-19 outbreaks in long-term care facilities in Ontario, Canada

Abstract

The novel coronavirus disease 2019 (COVID-19) has caused severe outbreaks in Canadian long-term care facilities (LTCFs). In Canada, over 80% of COVID-19 deaths during the first pandemic wave occurred in LTCFs. We sought to evaluate the effect of mitigation measures in LTCFs including frequent testing of staff, and vaccination of staff and residents. We developed an agent-based transmission model and parameterized it with disease-specific estimates, temporal sensitivity of nasopharyngeal and saliva testing, results of vaccine efficacy trials, and data from initial COVID-19 outbreaks in LTCFs in Ontario, Canada. Characteristics of staff and residents, including contact patterns, were integrated into the model with age-dependent risk of hospitalization and death. Estimates of infection and outcomes were obtained and 95% credible intervals were generated using a bias-corrected and accelerated bootstrap method. Weekly routine testing of staff with 2-day turnaround time reduced infections among residents by at least 25.9% (95% CrI: 23.3%–28.3%), compared to baseline measures of mask-wearing, symptom screening, and staff cohorting alone. A similar reduction of hospitalizations and deaths was achieved in residents. Vaccination averted 2–4 times more infections in both staff and residents as compared to routine testing, and markedly reduced hospitalizations and deaths among residents by 95.9% (95% CrI: 95.4%–96.3%) and 95.8% (95% CrI: 95.5%–96.1%), respectively, over 200 days from the start of vaccination. Vaccination could have a substantial impact on mitigating disease burden among residents, but may not eliminate the need for other measures before population-level control of COVID-19 is achieved.

Using simulation modelling and systems science to help contain COVID‐19: A systematic review

“…Fatehi et al ( 2021 ) evaluated the effectiveness of two forms of therapies, that is, remdesivir and convalescent plasma (CP) therapy. Forty‐five papers evaluated the impacts of different NPIs on COVID‐19 containment in specific organizations, including elementary or secondary schools (Asgary et al, 2021 ; Morrison et al, 2021 ; Zafarnejad & Griffin, 2021 ), colleges and universities (Bahl et al, 2021 ; Brennan et al, 2021 ; Goyal et al, 2021 ; Kharkwal et al, 2021 ; Lv et al, 2021 ), hospital (Campos et al, 2022 ; Huang et al, 2021 ; Mukherjee et al, 2021 ), army training post (Espana et al, 2021 ), refugee camp (Gilman et al, 2020 ), nursing and care home (Holmdahl et al, 2021 , 2022 ; Kahn et al, 2022 ; Lasser et al, 2021 ; Nguyen et al, 2021 ; Stevenson et al, 2021 ), long‐term care facility (Vilches et al, 2021 ), church (Rothrock et al, 2021 ), supermarket (Tong et al, 2021 ) and construction site (Alzu’bi et al, 2021 ). Three of them explored the effects of NPIs on special events, including two rituals of the Hajj (Al‐Shaery et al, 2021 ), wedding ceremony (Alzu’bi et al, 2021 ) and indoor gathering (Farthing & Lanzas, 2021b ).…”

Examining the association between reported COVID-19 symptoms and testing for COVID-19 in Canada: a cross-sectional survey

“…10 11 Yet, Canada's testing capacity has been limited to symptom-based screening. 12 This situation may have serious repercussion on the country's capacity to effectively control the disease in the wake of yet another wave of COVID-19, hence, warranting the need for a study that examines the association between self-reported symptoms and testing for COVID-19 in Canada. Despite Canada's relative success in containing the spread of COVID-19, little attention has been paid to assess its COVID-19 testing strategy.…”

Comparative analyses of eighteen rapid antigen tests and RT-PCR for COVID-19 quarantine and surveillance-based isolation

“…There has been extensive analysis and evaluation of the optimal strategies for both RT-PCR and RA testing to mitigate SARS CoV-2 transmission 4 – 6 , 8 – 18 , 36 , 37 . However, most of these analyses do not quantify the degree to which their use suppresses individual-level transmission in applications of quarantine 36 or serial surveillance testing with isolation of positives 10 , 11 , 13 , 15 , 16 , and most address a generalized or single RA test 5 , 6 , 9 , 11 , 12 , 16 , 18 , 36 , 37 , or focus only on RT-PCR 4 , 8 , 10 , 13 , 15 , 17 . In contrast, multiple RA tests have received regulatory Emergency Use Authorization (EUA) 38 , each with distinct temporal diagnostic sensitivity.…”