A recent study published by Oxford Academic (16/01/24) analyzed genetic and contact tracing data to evaluate the effectiveness of COVID-19 infection prevention measures in healthcare settings across 3 waves of the pandemic, including Omicron. Electronic contact records and viral sequencing from 12,933 infected healthcare workers and patients were examined.
During the first 2 waves, no transmission events were found between healthcare workers or patients despite over 600 identified contacts. This demonstrates effective infection control given the lack of cryptic transmission seen.
In the Omicron wave with over 1700 contacts, 8 possible transmission events were identified genetically, but only 1 was traced by contact records. This highlights the utility of viral sequencing in detecting cryptic infections.
The analysis shows infection prevention policies like masking and distancing successfully prevented COVID-19 transmission in healthcare settings prior to Omicron. Sequencing revealed some Omicron spread not caught by contact tracing, underscoring the importance of multifaceted prevention.
In summary, this rigorous study leveraging genetic analysis and contact networks provides real-world evidence that COVID-19 prevention measures in healthcare settings were largely effective across multiple waves and variants, with opportunities to further optimize policies as risks evolve.
The full study can be read here.