Secondary severe acute respiratory syndrome coronavirus 2 transmission from childcare workers versus teachers in school-associated screening events, Okinawa, Japan, January-March 2022

OBJECTIVES: To compare secondary severe acute respiratory syndrome coronavirus 2 transmission detected through reverse transcription polymerase chain reaction (RT-PCR) screening in childcare and school-aged settings during the Omicron wave. METHODS: ). RESULTS: : 0.15; 95% confidence interval: 0.06-0.33). No secondary infections were detected after teacher/staff-index events in junior high (n = 11) or high schools (n = 6). CONCLUSIONS: Childcare worker-index events in nurseries and kindergartens generated secondary cases in ≈30% of events, whereas teacher/staff-index events in elementary and secondary schools infrequently generated secondary cases under mitigation measures. Prioritizing screening and prevention resources toward childcare workers may improve efficiency when diagnostic capacity is constrained.