[An update on measles].

Measles is a highly contagious infectious disease, which needs more than 95% worldwide vaccination coverage of 2 doses to be eradicated. Despite an important involvement of the WHO for massive immunization, goals have not bean reached, and outbreaks can occur at any time in many countries, including Western Europe. In France, 22,000 cases were identified between 2009 and 2011, mainly in infants and young adults, which are not or not enough vaccinated (one dose). In 2012, even though the number of cases has drastically decreased, the outbreak is still going on, especially in South of France. That is why every clinician needs to be concerned about the clinical manifestations of the disease, and its complications. Besides a febrile rash, measles is often responsible of pneumonia and biologic hepatitis in adults. Hepatitis does not seem frequent in children. Clinicians need to be aware of specific complications, like encephalitis in case of cellular immunodepression, high risk of pneumonia in pregnant women. In patients previously vaccinated, incidence of complications is the same but patients are not contagious. Even if measles diagnosis is clinical, blood confirmation by serology is recommended in France when possible. Outcome is mainly favourable, but measles is not well-tolerated with high levels of hospitalisation even without any complication. Vaccination is the only way to protect against it.