Comparison of risk factors for SARS-CoV-2 infection among healthcare workers during Omicron and Delta dominance periods in Japan.
J Hosp Infect
; 134: 97-107, 2023 Apr.
Article
in English
| MEDLINE | ID: covidwho-2242693
ABSTRACT
BACKGROUND:
The risk factors for coronavirus disease (COVID-19) among healthcare workers (HCWs) might have changed since the emergence of the highly immune evasive Omicron variant.AIM:
To compare the risk factors for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among HCWs during the Delta- and Omicron-predominant periods.METHODS:
Using data from repeated serosurveys among the staff of a medical research centre in Tokyo, two cohorts were established Delta period cohort (N = 858) and Omicron period cohort (N = 652). The potential risk factors were assessed using a questionnaire. Acute/current or past SARS-CoV-2 infection was identified by polymerase chain reaction or anti-nucleocapsid antibody tests, respectively. Poisson regression was used to calculate the risk ratio (RR) of infection risk.FINDINGS:
The risk of SARS-CoV-2 infection during the early Omicron-predominant period was 3.4-fold higher than during the Delta-predominant period. Neither working in a COVID-19-related department nor having a higher degree of occupational exposure to SARS-CoV-2 was associated with an increased infection risk during both periods. During the Omicron-predominant period, infection risk was higher among those who spent ≥30 min in closed spaces, crowded spaces, and close-contact settings without wearing mask (≥3 times versus never RR 6.62; 95% confidence interval 3.01-14.58), whereas no such association was found during the Delta period.CONCLUSION:
Occupational exposure to COVID-19-related work was not associated with the risk of SARS-CoV-2 infection in the Delta or Omicron period, whereas high-risk behaviours were associated with an increased infection risk during the Omicron period.Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
COVID-19
Type of study:
Cohort study
/
Observational study
/
Prognostic study
Topics:
Variants
Limits:
Humans
Country/Region as subject:
Asia
Language:
English
Journal:
J Hosp Infect
Year:
2023
Document Type:
Article
Affiliation country:
J.jhin.2023.01.018
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