A-Z Index × Submit A-Z Index × Submit A-Z Index Search Dropdown × Submit Facebook Twitter LinkedIn Syndicate Emerging Infectious Disease journal ISSN: 1080-6059 Disclaimer: Early release articles are not considered as final versions. Any changes will be reflected in the online version in the month the article is officially released.
An ongoing measles outbreak in Israel, involving ≈3,200 cases and 16 deaths, threatens the country’s measles elimination status and reflects declining vaccination rates observed globally and within Israel. Epidemiologic investigations supported by sequencing suggest that a single importation triggered the outbreak, underscoring the critical role of rapid genomic surveillance in outbreak control.
Measles is a highly contagious, vaccine-preventable disease; clinical manifestations typically include high fever, maculopapular rash, cough, and conjunctivitis. Severe complications, including pneumonia and encephalitis, can occur in up to 30% of cases, and the case-fatality rate is ≈1/1,000 cases ( 1 ). Despite an effective vaccine (measles, mumps, and rubella [MMR]), measles remains a major global health concern; in 2025, Romania, Vietnam, Morocco, and the United States reported outbreaks ( 2 – 4 ).
In Israel, MMR vaccine coverage has declined in recent years to 83% receiving the first dose at <25 months of age and 87% a second dose at <8 years of age. Corresponding rates are 83% and 85% in Jerusalem and 89% and 93% in the Central District; coverage is lower in Ultra-Orthodox communities (Israel Ministry of Health, unpub. data). Israel achieved measles elimination in 2015, but outbreaks continue, including >4,000 cases in 2018–2019 and smaller outbreaks during 2023–2024 ( 5 – 7 ). We report on an ongoing measles outbreak that began in Israel in April 2025.
During April 7, 2025–February 28, 2026, a total of 3,203 measles cases, including 16 deaths, were reported across Israel, the largest outbreak since 2018–2019 ( 8 ). Epidemiologic investigations found 13 case-patients had a history of travel abroad shortly before illness onset ( Table ). Among reported case-patients, mean age was 5.58 years (SD 9.35 years; range 1 month–73 years); 82.7% were unvaccinated, 7.1% were partially vaccinated, 2.2% were fully vaccinated, and 8.5% had unknown vaccination status.
As part of routine surveillance, 132 measles virus–positive samples collected during April 2025–February 2026 were selected for sequencing (Appendix). Samples were sequenced on the basis of the following criteria: all available imported cases, all travel-associated cases, representative samples from newly affected areas, and randomized samples collected in established outbreak locations every 2 weeks throughout the outbreak. Samples were excluded from sequencing when epidemiologic data showed that transmission occurred in established measles-positive locations (i.e., same street or household) (Appendix). Complete measles virus genomes were sequenced ( 9 ) (Appendix) and used for phylogenetic analysis to support transmission chain reconstruction. The N450 region of the measles viral genome confirmed the sequences as genotype B3, matching the reference MVs/Quetta.PAK/44.20 strain from Pakistan.
Figure 1 . Phylogenetic analysis from investigation of genomic and epidemiologic insights into ongoing measles outbreak, Israel, 2025–2026. Phylogenetic tree including 132 sequences from Israel collected during April 2025–February 2026 and 29 global...
Figure 2 . Geo…