Dataset Information

Systematic on-site testing for SARS-CoV-2 infection among asymptomatic essential workers in Montreal, Canada: a prospective observational and cost-assessment study.

ABSTRACT:

Background

Essential workers are at increased risk for SARS-CoV-2 infection. We aimed to estimate the yield, acceptability and cost of systematic workplace-based testing of asymptomatic essential workers for SARS-CoV-2 infection.

Methods

From Jan. 27 to Mar. 12, 2021, we prospectively recruited non-health care essential businesses in Montréal, Canada, through email or telephone contact. Two trained mobile teams, each composed of 2 non-health care professionals, visited businesses. Consenting asymptomatic employees provided saline gargle samples under supervision. Samples were analyzed by means of reverse transcription polymerase chain reaction (RT-PCR). At businesses with outbreaks (≥ 2 participants with a positive result), we retested all participants with a negative result on initial testing. Our primary outcomes were yield (proportion of test results that were positive), acceptability (proportion of participants estimated to be present at the business who agreed to participate) and costs (including training, sample collection and analysis, and communicating results). Our secondary outcome was identification of factors associated with a positive test result on multivariable logistic regression.

Results

Of the 366 businesses contacted, 69 (18.8%) agreed to participate. Nineteen businesses (28%) were manufacturers or suppliers, 12 (17%) were in auto sales or repair, and 11 (16%) were in childcare; the corresponding number of employees was 1225, 242 and 113. The median number of participants per business was 13 (interquartile range [IQR] 8-22). Of an estimated 2348 employees on site, 2128 (90.6%) participated (808 [38.0%] female, median age 48 [IQR 37-57] yr). Of the 2626 tests performed, 53 (2.0%) gave a positive result. Self-reported nonwhite ethnicity (adjusted odds ratio [OR] 3.7, 95% confidence interval [CI] 1.4-9.9) and a negative SARS-CoV-2 test result before the study (adjusted OR 0.4, 95% CI 0.2-0.8) were associated with a positive test result. Five businesses were experiencing an outbreak; at these businesses, 40/917 participants (4.4%) had a positive result on the initial test. We repeated testing for employees with initially negative results at 3 of these businesses over 2-3 weeks: 8/350 participants (2.3%) had a positive result on the second test, and none had a positive result on the third and fourth tests; no employer reported new positive results after our final visit (up to Mar. 26, 2021). At the remaining 64 businesses, 1211 participants were tested once, of whom 5 (0.4%) had a positive result. The per-person RT-PCR cost was $34, and all other costs, $8.67.

Interpretation

On-site saline gargle sampling of essential workers for SARS-CoV-2 testing was acceptable and of modest cost, and appears most useful in the context of outbreaks. This sampling strategy should be evaluated further as a component of efforts to prevent SARS-CoV-2 transmission. PREPRINT: medRxiv - doi:10.1101/2021.05.12.21256956.

SUBMITTER: Campbell JR

PROVIDER: S-EPMC9259431 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BackgroundBecause of their direct patient contact, healthcare workers (HCW) face an unprecedented risk of exposure to COVID-19. The aim of this study was to examine incidence of COVID-19 disease among asymptomatic HCW and community participants in Northern Virginia during 6 months of follow-up.MethodsThis is a prospective cohort study that enrolled healthy HCW and residents who never had a symptomatic COVID-19 infection prior to enrolment from the community in Northern Virginia from April to November 2020. All participants were invited to enrol in study, and they were followed at 2-, and 6-months intervals. Participants were evaluated by commercial chemiluminescence SARS-CoV-2 serology assays as part of regional health system and public health surveillance program to monitor the spread of COVID-19 disease.FindingsOf a total of 1,819 asymptomatic HCW enrolled, 1,473 (96%) had data at two-months interval, and 1,323 (73%) participants had data at 6-months interval. At baseline, 21 (1.15%) were found to have prior COVID-19 exposure. At two-months interval, COVID-19 rate was 2.8% and at six months follow-up, the overall incidence rate increased to 4.8%, but was as high as 7.9% among those who belong to the youngest age group (20-29 years). Seroconversion rates in HCW were comparable to the seropositive rates in the Northern Virginia community. The overall incidence of COVID-19 in the community was 4.5%, but the estimate was higher among Hispanic ethnicity (incidence rate = 15.3%) potentially reflecting different socio-economic factors among the community participants and the HCW group. Using cross-sectional logistic regression and spatio-temporal mixed effects models, significant factors that influence the transmission rate among HCW include age, race/ethnicity, resident ZIP-code, and household exposure, but not direct patient contact.InterpretationIn Northern Virginia, the seropositive rate of COVID-19 disease among HCW was comparable to that in the community.

Project description:The purpose of this study was to describe dietary patterns among 1636 French-speaking men residing in Montreal, Canada and to assess sociodemographic and lifestyle characteristics of men adhering to the dietary patterns identified. Participants were population controls from the Prostate Cancer and Environment Study, a case-control study conducted between 2006 and 2011 in Montreal. Information on diet was collected using a food frequency questionnaire, and principal component analysis, a data-driven method and a posteriori method, was used to identify dietary patterns. Three dietary patterns were identified; Healthy, Modified Western - Salty and Modified Western - Sweet patterns accounted for 7.0%, 5.4%, and 3.2% of the variance, respectively. The Healthy pattern was characterized by consumption of fruits, vegetables, vegetable soup, chicken, fish and seafood, cheese, rice, yogurt, and wine. The Modified Western - Salty pattern included high loadings for beef, pork, chicken, hot-dogs or sausages, cold cuts, bacon, barbecue cooking, meat slightly blackened, potatoes, pasta with tomato sauce, pizza, pastries, dark carbonated soft drinks, ice cream, and white bread. The third pattern, labelled as Modified Western - Sweet, had high loadings of cookies, muffins, cakes, pastries, pies, ice cream, fruits and vegetables. In multivariate analyses, the Healthy pattern was positively associated with higher income and education, moderate recreational physical activity and less heavy smoking, and inversely associated with French ancestry. The Modified Western - Salty pattern was positively associated with French, other European, and Latino ancestries, and with married and common-law relationships. Finally, the Modified Western - Sweet pattern was more common among men of French ancestry and users of vitamin/mineral supplements. The Healthy pattern has been frequently observed in other Western populations, but the other two are described for the first time in a study population of men.

Project description:BackgroundPrecarious status migrants are a group of persons who are vulnerable, heterogeneous, and often suspicious of research teams. They are underrepresented in population-based research projects, and strategies to recruit them are described exclusively in terms of a single cultural group. We analyzed the recruitment strategies implemented during a research project aimed at understanding precarious status migrants' health status and healthcare access in Montreal, Canada. The research sample consisted of 854 persons recruited from a variety of ethnocultural communities between June 2016 and September 2017. This article analyzes the strategies implemented by the research team to respond to the challenges of that recruitment, and assess the effectiveness of those strategies. Based on the results, we share the lessons learned with a view to increasing precarious status migrants' representation in research.MethodA mixed sequential design was used to combine qualitative data gathered from members of the research team at a reflexive workshop (n?=?16) and in individual interviews (n?=?15) with qualitative and quantitative data collected using the conceptual mapping method (n?=?10).ResultsThe research team encountered challenges in implementing the strategies, related to the identification of the target population, the establishment of community partnerships, and suspicion on the part of the individuals approached. The combination of a venue-based sampling method, a communications strategy, and the snowball sampling method was key to the recruitment. Linking people with resources that could help them was useful in obtaining their effective and non-instrumental participation in the study. Creating a diverse and multicultural team helped build trust with participants. However, the strategy of matching the ethnocultural identity of the interviewer with that of the respondent was not systematically effective.ConclusionThe interviewers' experience and their understanding of the issue are important factors to take into consideration in future research. More over, the development of a community resource guide tailored to the needs of participants should be major components of any research project targeting migrants. Finally, strategies should be implemented as the result of a continuous reflexive process among all members of the research team.