Genomic and Epidemiologic Insights into Ongoing Measles Outbreak, Israel, 2025-2026

Area of Science:

• Epidemiology
• Genomic Surveillance
• Public Health

Background:

• Measles outbreaks pose a significant threat to public health, potentially jeopardizing disease elimination status.
• Declining vaccination rates globally and within Israel are contributing factors to the resurgence of measles.
• The current measles outbreak in Israel involves approximately 3,200 cases and 16 deaths.

Purpose of the Study:

• To investigate the cause and spread of the ongoing measles outbreak in Israel.
• To assess the impact of declining vaccination rates on measles transmission.
• To emphasize the importance of genomic surveillance in controlling infectious disease outbreaks.

Main Methods:

• Epidemiologic investigations were conducted to trace the outbreak's origins and transmission patterns.
• Genomic sequencing was employed to support epidemiologic findings and identify the source of importation.
• Analysis of vaccination rates in Israel and globally was performed.

Main Results:

• The outbreak appears to have been triggered by a single importation event.
• Genomic data corroborated the epidemiologic findings regarding the outbreak's source.
• The outbreak has placed Israel's measles elimination status at risk.

Conclusions:

• Rapid genomic surveillance is a critical tool for effective outbreak control.
• Addressing declining vaccination rates is essential to prevent future measles outbreaks and maintain elimination status.
• Public health interventions must be informed by both epidemiologic and genomic data.