Measles

麻疹

Evidence-backed information EN 6/7 applicable sections · ZH 6/7 applicable sections Updated Oct 23, 2026

Measles is a highly contagious viral disease that remains a leading cause of death among young children worldwide despite an effective vaccine ^[1]^[2]. Global vaccination efforts prevented an estimated 59 million deaths between 2000 and 2024, yet approximately 95,000 people died of measles in 2024, mostly children under five ^[1]^[2]. Outbreak reports from the United States and the Region of the Americas indicate continued transmission in these areas ^[3]^[4].

Read the full clinical and epidemiological profile 7

Definition

Measles is a highly contagious, potentially fatal, vaccine-preventable disease caused by the measles virus ^[1]^[2]^[5]. It infects the respiratory tract and subsequently disseminates throughout the body ^[1].

Clinical features

Illness typically begins 7–14 days after exposure with high fever, cough, runny nose, and bloodshot eyes, followed by a generalized maculopapular rash ^[1]^[2]^[5]. Tiny white spots may appear inside the mouth, and vaccinated persons can exhibit milder or absent symptoms ^[2]^[5]. Severe disease is more frequent among poorly nourished young children and those with weakened immunity ^[2].

Epidemiology

Before widespread vaccination after 1963, major epidemics occurred every two to three years causing about 2.6 million annual deaths ^[1]. Measles still causes substantial mortality, with over 95% of the 95,000 deaths in 2024 occurring in low-income countries with weak health systems, especially in Africa and Asia ^[1]^[2]. Reported case numbers in 2020 must be interpreted cautiously due to COVID-19 surveillance disruption, and pandemic-related vaccination interruptions raise resurgence risk ^[5]. Outbreaks have been documented in the United States and the Region of the Americas ^[3]^[4].

Transmission

Measles is one of the world’s most contagious diseases, spread by contact with infected nasal or throat secretions (coughing or sneezing) or breathing the air that was breathed by someone with measles ^[1]. The virus remains active and contagious in the air or on infected surfaces for up to two hours ^[1]. It can be transmitted by an infected person from four days prior to the onset of the rash to four days after the rash erupts ^[1]. Measles is also transmitted via droplets from the nose, mouth or throat of infected persons ^[2].

Prevention

Routine childhood vaccination with the safe and effective measles vaccine is the primary means to prevent illness and onward spread ^[1]^[2]. Mass immunization campaigns in areas with low routine coverage are key public-health strategies to reduce deaths ^[2]. Achieving and maintaining high immunization coverage is essential to avert resurgences linked to disrupted services ^[5].

Surveillance note

GlobalID source-data note: Finland THL source code 170 is displayed in the upstream English dimension as ‘Cinderella disease’. The official Finnish label is ‘Tuhkarokko’, meaning measles; this is an upstream translation error, not a mapping to a different disease.

References

1 World Health Organization. Measles [Internet]. cited 3 Sept 2026. Available from: https://www.who.int/news-room/fact-sheets/detail/measles
2 World Health Organization. Measles [Internet]. cited 3 Sept 2026. Available from: https://www.who.int/health-topics/measles
3 World Health Organization. Measles - United States of America [Internet]. Disease Outbreak News. cited 23 Apr 2026. Available from: https://www.who.int/2025-DON561
4 World Health Organization. Measles – Region of the Americas [Internet]. Disease Outbreak News. cited 23 Apr 2026. Available from: https://www.who.int/2025-DON565
5 Hübschen JM et al. Measles. Lancet. 2022 Feb 12. PMID: 35093206. doi: 10.1016/S0140-6736(21)02004-3. PubMed: https://pubmed.ncbi.nlm.nih.gov/35093206/