Measles is a highly infectious viral illness with the potential for serious and life threatening complications. Travel remains an important factor in the international spread of measles.

Measles is spread by airborne or droplet transmission. Initial symptoms can include fever, runny nose, conjunctivitis and cough. A rash usually appears a few days later that starts at the head and spreads to the trunk and limbs over three to four days. Individuals are infectious from the time when the first symptom appears to four days after the appearance of the rash. The incubation period (the time from exposure to the virus to developing symptoms) is about ten days (ranging between seven and 18 days).
 
Complications of measles infection can occur including otitis media (ear infections), diarrhoea and convulsions (fits). Rarely encephalitis (inflammation of the brain) or sub-acute sclerosing pan-encephalitis (chronic late onset brain inflammation leading to death) are reported. The risk of death from the complications of measles infection is age-related; it is high in children younger than one year and in adults.
 
Measles is endemic in many countries. In particular, countries experiencing or recovering from a conflict or natural disaster are particularly prone to outbreaks of measles. Damage to health infrastructure and health services can interrupt routine immunisation schedules and overcrowding in residential camps greatly increases the risk of infection. 

Limitations in national surveillance and reporting systems together with cases not seeking healthcare, and so not being accounted for, result in an underestimate of the number of measles cases globally. WHO information on global surveillance of measles

Some verified outbreak reports for measles, mumps and rubella worldwide are available on our Outbreak Surveillance Database.

Prevention

Individuals who have never had measles infection or are unvaccinated or incompletely vaccinated, may be at risk from measles when visiting countries reporting cases, especially if staying with friends or family and mixing with the local population.

All UK travellers should ensure they are up-to-date with the Measles, Mumps and Rubella (MMR) vaccination, according to current UK recommendations.

* MMR can be given from six months of age in some circumstances, e.g. before travel to an endemic country and/or where an outbreak is occurring. If first dose is given before the child’s first birthday, two further doses should be given at 12-13 months and at 3 years and 4 months to 5 years.
** Children who are travelling to measles endemic areas or to an area where there is a current outbreak who have received one dose of MMR at the routine age should have the second dose brought forward to at least one month after the first. If the child is under 18 months of age and the second dose is given within three months of the first dose, then the routine pre-school dose (a third dose) should be given in order to ensure full protection.

Additional guidance on measles vaccine for individuals who are travelling or going to reside abroad is available in Immunisation against infectious disease: measles.

Advice on immunisation against measles is also available for those whose immunisation status is uncertain.

In the UK, measles is a notifiable disease. Any case of suspected measles should be notified to the local Health Protection Team.

Resources

• Public Health England: Immunisation against infectious disease. Measles
• Public Health England: Measles symptoms, diagnosis, complications and treatment
• Public Health England: Measles guidance, data and analysis
• World Health Organization. Measles Fact Sheet: November 2016
• Further details on measles containing vaccines can be found in: Summary of Product Characteristics (SPC), Electronic Medicines Compendium
• European Centre for Disease Prevention and Control: Monthly measles epidemiological updates