RESUMEN
BACKGROUND: Health care workers (HCWs) are occupationally exposed to severe acute respiratory syndrome coronavirus (SARS-CoV-2). This study aimed to characterize COVID-19 in HCWs at an oncology hospital in Mexico City over 2-years, identify factors associated with severity, and establish transmission dynamics. METHODS: This retrospective study included HCWs with confirmed COVID-19. Socio-demographic, clinical, and outcome data were retrieved from March 2020 to March 2022. We compared the proportion of HCWs affected in each wave. A survey on COVID-19 transmission dynamics was conducted in a subgroup. RESULTS: We included 1,058 workers. The risk of COVID-19 was higher during the Omicron odds ratio (OR 2.10, 95% confidence interval [CI] 1.77-2.50, P < .001). Age ≥41 years old (OR 6.32, 95% CI 2.4-16.62) and being administrative staff (OR 5.51, 95% CI 1.72-17.6) or medical staff (OR 6.82, CI 95% 1.77-26.23), compared to nursing staff, were associated with severity. Vaccination with ≥1 vaccine against SARS-CoV-2 was a protective factor for severe disease (OR 0.04, 95% CI 0.005-0.331). CONCLUSIONS: This study highlights the impact of COVID-19 on HCWs in a cancer hospital in Mexico City and the impact of vaccination as a protective factor against severity.