PHHP 111 - Lessons Learned from a Measles Outbreak in a Pediatric Population in Ohio

Background: The Centers for Disease Control (CDC) has recognized the increased risk for outbreaks due to vaccine hesitancy. Lack of access, cultural influences, and misinformation can contribute to inadequately vaccinated populations, and these may be especially prominent in immigrant populations. Measles has been linked to insufficient vaccination and four global genotypes have been identified -- B3, D4, D8, D11. The purpose of this outbreak investigation is to describe a cluster of measles in an immigrant population in the Midwestern United States.

Methods: This was a retrospective cohort investigation. Measles cases were identified using electronic medical and immunization records, diagnostic testing, line listing of exposed persons, and classified as a presumptive case based on local health department criteria.

Results: The outbreak contained 85 confirmed measles cases with onset dates from October 22nd, 2022, to December 24th, 2022. The children ranged in age from 6 months to 15 years with a median age of 1 year. Somali descent accounted for 70% of cases. Childcare attendees accounted for 58% of all cases. B3 was the prominent genotype identified in all positive cases. 2,849 patient exposures occurred within a pediatric healthcare system. The 2022 Ohio measles outbreak was the 5th largest since measles elimination.

Conclusions: This large-scale measles outbreak shows the impact of eligible children not being vaccinated and potential for widespread transmission. Migrant, high-risk populations require additional education, enhanced access, and outreach to encourage Measles, Mumps, Rubella vaccination. The downstream implications can result in risk of disease transmission to unvaccinated children and can pose a particular burden on healthcare systems and public health departments.