Large measles epidemic in Switzerland from 2006 to 2009: consequences for the elimination of measles in Europe.

Switzerland adheres to the objective of eliminating measles within the European region of the World Health Organization (WHO) by 2010. After several years with a relatively low annual incidence rate (0.3 to 1 case per 100,000 inhabitants), there has been a large epidemic of measles from November 2006 to August 2009. By mid September 2009, 4,415 cases were notified by physicians and laboratories, corresponding to an incidence rate of 15 per 100,000 in 2007 and 29 per 100,000 in 2008; by far the highest rates in Europe. This exceptionally long nationwide epidemic comprised three successive waves, with peaks in August 2007 (171 cases), March 2008 (569 cases) and March 2009 (417 cases). It mainly affected children aged from five to 14 years (48% of cases). Most cases were not vaccinated (93%) or were incompletely vaccinated (5%). In total 656 patients (15%) suffered complications or were hospitalised. Insufficient, spatially heterogeneous immunisation coverage (87% for at least one dose at the age of two years at the national level) has allowed a sequence of numerous outbreaks to occur, despite the gradual strengthening of measures to control the disease. Several exportations to Europe (81 in 2007 and 2008) and to the rest of the world (10 for the whole of the epidemic) have in some instances caused large outbreaks. The epidemic was a threat to the goal of eliminating measles in Switzerland and in Europe. The Federal Office of Public Health (FOPH) and its partners are currently working on a national strategy to eliminate measles.