tetano
Editor, Senior Moderator
J Hosp Infect
. 2023 Feb 16;S0195-6701(23)00044-0.
doi: 10.1016/j.jhin.2023.01.018. Online ahead of print.
Comparison of risk factors for SARS-CoV-2 infection among healthcare workers during Omicron and Delta dominance periods in Japan
Y Li[SUP] 1 [/SUP], S Yamamoto[SUP] 1 [/SUP], Y Oshiro[SUP] 2 [/SUP], N Inamura[SUP] 2 [/SUP], T Nemoto[SUP] 2 [/SUP], K Horii[SUP] 3 [/SUP], J S Takeuchi[SUP] 4 [/SUP], T Mizoue[SUP] 5 [/SUP], M Konishi[SUP] 1 [/SUP], M Ozeki[SUP] 2 [/SUP], H Sugiyama[SUP] 6 [/SUP], W Sugiura[SUP] 7 [/SUP], N Ohmagari[SUP] 8 [/SUP]
Affiliations
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: COVID-19; Delta variant; Healthcare workers; Omicron variant; SARS-CoV-2.
. 2023 Feb 16;S0195-6701(23)00044-0.
doi: 10.1016/j.jhin.2023.01.018. Online ahead of print.
Comparison of risk factors for SARS-CoV-2 infection among healthcare workers during Omicron and Delta dominance periods in Japan
Y Li[SUP] 1 [/SUP], S Yamamoto[SUP] 1 [/SUP], Y Oshiro[SUP] 2 [/SUP], N Inamura[SUP] 2 [/SUP], T Nemoto[SUP] 2 [/SUP], K Horii[SUP] 3 [/SUP], J S Takeuchi[SUP] 4 [/SUP], T Mizoue[SUP] 5 [/SUP], M Konishi[SUP] 1 [/SUP], M Ozeki[SUP] 2 [/SUP], H Sugiyama[SUP] 6 [/SUP], W Sugiura[SUP] 7 [/SUP], N Ohmagari[SUP] 8 [/SUP]
Affiliations
- PMID: 36805085
- DOI: 10.1016/j.jhin.2023.01.018
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: COVID-19; Delta variant; Healthcare workers; Omicron variant; SARS-CoV-2.