National Study of Public Measles Exposures (2025)

When someone with measles visits a public place, health departments must act quickly to identify and notify people who may have been exposed. This process can be time- and resource-intensive, especially during large outbreaks.

However, there is limited data on how often these public exposures actually lead to additional cases. This makes it difficult for health departments to prioritize efforts and use resources efficiently.

This study brings together data from across the United States to:

• Understand when public exposures lead to transmission
• Identify patterns and risk factors
• Provide evidence to improve outbreak response

CORI is working with health departments nationwide to collect and validate data from 2025 measles exposure events. All data are de-identified and securely shared.

• Collect data: Compile information on measles cases and public exposure events from public sources
• Validate data: Partner with health departments to confirm details and fill gaps
• Analyze patterns: Identify when and where transmission occurs
• Share findings: Publish results to inform public health practice

• Findings from this study will help:

  • Improve how health departments respond to measles exposures
  • Support more efficient use of contact tracing resources
  • Inform future public health guidance
  • Strengthen data standards for outbreak response