Prospective observational study and serosurvey of SARS-CoV-2 infection in asymptomatic healthcare workers at a Canadian tertiary care center

Ferreira, Victor H; Chruscinski, Andrzej; Kulasingam, Vathany; Pugh, Trevor J.; Dus, Tamara; Wouters, Brad; Oza, Amit M.; Ierullo, Matthew; Ku, Terrance; Majchrzak-Kita, Beata; Humar, Sonika; Bahinskaya, Ilona; Pinzon, Natalia; Zhang, Jianhua; Heisler, Lawrence E.; Krzyzanowski, Paul M.; Lam, Bernard; Lungu, Ilinca M.; Manase, Dorin; Pace, Krista; Mashouri, Pouria; Brudno, Michael; Garrels, Michael; Mazzulli, Tony; Cybulsky, Myron I.; Humar, Atul; Kumar, Deepali

doi:10.1371/journal.pone.0247258

Cited by 15 publications

(15 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ten studies did not report the age of the participants. Only 15 studies reported the median age [39, 47, 57, 59, 61, 64, 86, 107, 118, 121, 123, 124, 127, 137, 145] and only 21 studies reported the sex distribution of people with asymptomatic SARS-CoV-2 [39, 40, 46, 48, 50, 57, 59, 61, 63, 64, 72, 86, 87, 107, 113, 118, 121, 123, 124, 127, 137] (Table 1, S2 Table). The types of included studies changed across the four versions of the review.…”

Section: Resultsmentioning

confidence: 99%

“…Amongst all 130 included studies, 88 studies used more than one method of follow-up to ascertain asymptomatic status (Table 1, S2 Table). Only 22 of 130 studies reported the median or mean age [38,47,70,76,77,83,85,95,99,119-121,124,126,128,133,134,139,143,146,152,164] and only five studies included children only [65,67,110,115,118]. Only 31 studies reported the sex of people with asymptomatic SARS-CoV-2 (Table 1, S2 Table) [38,47,51,53,70,71,75,76,83,85,95,99,107,119-122,124,126,128,133,134,139,143,146,147,150,153,158,162,164].…”

Section: Resultsmentioning

confidence: 99%

“…Only 22 of 130 studies reported the median or mean age [38,47,70,76,77,83,85,95,99,119-121,124,126,128,133,134,139,143,146,152,164] and only five studies included children only [65,67,110,115,118]. Only 31 studies reported the sex of people with asymptomatic SARS-CoV-2 (Table 1, S2 Table) [38,47,51,53,70,71,75,76,83,85,95,99,107,119-122,124,126,128,133,134,139,143,146,147,150,153,158,162,164]. The types of included studies changed across the five versions of the review.…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Occurrence and transmission potential of asymptomatic and presymptomatic SARS-CoV-2 infections: update of a living systematic review and meta-analysis

Buitrago-Garcia

Ipekci

Heron

et al. 2022

Preprint

View full text Add to dashboard Cite

BACKGROUND Debate about the level of asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection continues. The amount of evidence is increasing and study designs have changed over time. We conducted a living systematic review to address three questions: (1) Amongst people who become infected with SARS-CoV-2, what proportion does not experience symptoms at all during their infection? (2) What is the infectiousness of asymptomatic and presymptomatic, compared with symptomatic, SARS-CoV-2 infection? (3) What proportion of SARS-CoV-2 transmission in a population is accounted for by people who are asymptomatic or presymptomatic? METHODS AND FINDINGS The protocol was first published on 1 April 2020 and last updated on 18 June 2020. We searched PubMed, Embase, bioRxiv and medRxiv, aggregated in a database of SARS-CoV-2 literature, most recently on 2 February 2021. Studies of people with PCR-diagnosed SARS-CoV-2, which documented symptom status at the beginning and end of follow-up, or mathematical modelling studies were included. Studies restricted to people already diagnosed, of single individuals or families, or without sufficient follow-up were excluded. One reviewer extracted data and a second verified the extraction, with disagreement resolved by discussion or a third reviewer. Risk of bias in empirical studies was assessed with a bespoke checklist and modelling studies with a published checklist. All data syntheses were done using random effects models. Review question (1): We included 94 studies. Heterogeneity was high and we could not reliably estimate values for the proportion of asymptomatic infections overall (interquartile range 13-45%, prediction interval 2-89%), or in studies based on screening of defined populations (interquartile range 18-59%, prediction interval 3-95%). In screening studies at low risk of information bias, the prediction interval was 4-69% (summary proportion 23%, 95% CI 14-35%). In 40 studies based on contact or outbreak investigations, the summary proportion asymptomatic was 18% (95% CI 14-24%, prediction interval 3-64%) and, in studies at low risk of selection bias, 25% (95% CI 18-33%, prediction interval 5-66%). (2) The secondary attack rate in contacts of people with asymptomatic infection compared with symptomatic infection was 0.43 (95% CI 0.05-3.44, 5 studies). (3) In 11 modelling studies fit to data, the proportion of all SARS-CoV-2 transmission from presymptomatic individuals was higher than from asymptomatic individuals. Limitations of the evidence include high heterogeneity in studies that were not designed to measure persistently asymptomatic infection, high risks of selection and information bias, and the absence of studies about variants of concern or in people who have been vaccinated. CONCLUSIONS This review does not provide a summary estimate of the proportion of asymptomatic SARS-CoV-2 across all study designs. In studies based on contact and outbreak investigation, most SARS-CoV-2 infections were not persistently asymptomatic. Summary estimates from meta-analysis may be misleading when variability between studies is extreme. Without prospective longitudinal studies with methods that minimise selection and measurement biases, further updates with the study types included in this living systematic review are unlikely to be able to provide a reliable summary estimate of the proportion of asymptomatic infections caused by wild-type SARS-CoV-2.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Occurrence and transmission potential of asymptomatic and presymptomatic SARS-CoV-2 infections: update of a living systematic review and meta-analysis

Buitrago-Garcia

Ipekci

Heron

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

“…It is well established that asymptomatic carriers are able to spread infection (Ooi andLow, 2020, Rasmussen andPopescu, 2021). In an observational study from Canada, symptomatic SARS-CoV-2 infection in HCWs was found to be more common than asymptomatic, and only 0.50% of the asymptomatic participants were PCR-positive (Ferreira et al, 2021). In our study, 12.3% of seropositive HCWs did not report any symptoms, highlighting that although asymptomatic infections are infrequent, they may cause outbreaks among both patients and co-workers.…”

Section: Discussionmentioning

confidence: 99%

SARS-CoV-2 seroprevalence among 7950 healthcare workers in the Region of Southern Denmark

Huth

Lillevang

Røge

et al. 2021

International Journal of Infectious Diseases

View full text Add to dashboard Cite

Objective Health-care workers (HCWs) carry a pronounced risk of acquiring severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We aimed to determine the seroprevalence and potential risk factors of SARS-CoV-2 infection among HCWs in the Region of Southern Denmark after the first pandemic wave in the spring of 2020. Methods Observational study conducted May-June 2020. SARS-CoV-2 IgG and IgM antibodies were measured in plasma. Participants were asked to complete a questionnaire consisting of demographic information, risk factors and COVID-19-related symptoms. Results A total of 7,950 participated. The seroprevalence of SARS-CoV-2 antibodies was 2.1% (95% CI 1.8-2.4). Seropositive participants were significantly older (mean age 48.9 years vs. 46.7 years in seronegative, P=0.022) and a higher percentage had experienced at least one symptom of COVID-19 (P<0.001). The seroprevalence was significantly higher among HCW working on dedicated COVID-19 wards (3.5%, OR 2.02 (95% CI 1.44-2.84). Seroprevalence was significantly related to 11-50 close physical contacts per day outside work (OR 1.54, 95% CI 1.07-2.22). Conclusion The prevalence of SARS-CoV-2 antibodies was low in HCWs. However, the occupational risk for contracting the infection is higher for those working on dedicated COVID-19 wards. Further, our results imply that attention should be paid to occupational risk factors in planning pandemic preparedness.

show abstract

“…This figure is 4.1% for HCWs of wards with patients with respiratory symptoms without laboratory evidence of SARS-CoV-2 positivity [8]. Reports of antibody positivity in HCW cohorts early in the pandemic ranged widely across studies, hospitals, and geographic settings from 3.4-1.4% in a large Canadian tertiary care center [9], 3.2% in an oncology department of an Austrian university hospital [10], to just 1% in a Californian regional health-care delivery network [11]. To date, there are no published data indicating the incidence of asymptomatic positive COVID-19 HCWs employed at a center dedicated exclusively to the treatment of cancer patients.…”

Section: Introductionmentioning

confidence: 99%

Prospective Observational COVID-19 Screening and Monitoring of Asymptomatic Cancer Center Health-Care Workers with a Rapid Serological Test

et al. 2021

View full text Add to dashboard Cite

Health-care workers (HCW) are at high risk for SARS-CoV-2 infection and, if asymptomatic, for transmitting the virus to fragile cancer patients. We monitored all asymptomatic HCWs of a cancer institute (94% of all employees agreed to enter the study) with the rapid serological test, VivaDiagTM, identifying SARS-CoV-2 associated-IgM/IgG. The tests were performed at time 0 (n = 606) and after 14 days (n = 393). Overall, the VivaDiagTM results of nine HCWs (1.5%) were positive, with one confirmed to be SARS-CoV-2-positive after oropharyngeal swab testing by RT-PCR. At time 0, all nine cases showed IgM expression while IgG was detected in only one. After 14 days, IgM persisted in all the cases, while IgG became evident in four. A chemiluminescence immunoassay (CLIA) confirmed IgM positivity in 5/13 VivaDiagTM positive cases and IgG positivity in 4/5 VivaDiagTM positive cases. Our study suggests that the VivaDiagTM test can be of help in identifying SARS-CoV-2 infected people in cohorts of subjects with a high prevalence.

show abstract

Prospective observational study and serosurvey of SARS-CoV-2 infection in asymptomatic healthcare workers at a Canadian tertiary care center

Cited by 15 publications

References 19 publications

Occurrence and transmission potential of asymptomatic and presymptomatic SARS-CoV-2 infections: update of a living systematic review and meta-analysis

Occurrence and transmission potential of asymptomatic and presymptomatic SARS-CoV-2 infections: update of a living systematic review and meta-analysis

SARS-CoV-2 seroprevalence among 7950 healthcare workers in the Region of Southern Denmark

Prospective Observational COVID-19 Screening and Monitoring of Asymptomatic Cancer Center Health-Care Workers with a Rapid Serological Test

Contact Info

Product

Resources

About