Further Efforts Needed to Achieve Measles Elimination in Germany: Results of an Outbreak investigation/Des Efforts Supplementaires Sont Necessaires Pour Parvenir a Eliminer la Rougeole En Allemagne : Resultats De I'investigation D'une Flambee epidemique/Se Requerira Un Mayor Esfuerzo Para Eliminar El Sarampion En Alemania: Resultados De la Investigacion De Un Brote

Background Germany, with 82 million inhabitants, is committed to the WHO goal of eliminating indigenous measles transmission in the European Region by 2010. (1,2) WHO recommends that at least 95% of children receive two doses of a measles-virus-containing vaccine (MVCV)--the first at 12 months of age and the second before school entry, (2) and that older children who are susceptible also be targeted for a two-dose vaccination. (2) A nationwide two-dose routine measles vaccination schedule was implemented in Germany in 1991. (3) Since 2001, the first dose has been recommended at 11-14 months and the second at 15-23 months of age. (3) Childhood vaccination is usually performed by paediatricians of general practitioners and is free of charge. Vaccinations are not mandatory in Germany, but status is routinely documented from vaccination cards presented at school entry examinations. In 2001, measles became a notifiable disease in Germany, which resulted in strengthened surveillance. The number of measles cases notified in Germany decreased from 6037 in 2001 to a historical low of 122 in 2004. (4) In 2005, a resurgence was observed due to outbreaks in two states (776 cases). The highest attack rate occurred in children aged 1-4 years in Hesse and 5-9 years in Bavaria. (4) In 2006, a large outbreak occurred in the densely-populated state of North Rhine-Westphalia (NRW), with 18 million inhabitants. The epidemiological distribution of measles in Germany is a determinant of measles elimination in Europe because Germany has the largest population in the European Union; regions with high population densities; and geographic, economic and migrational characteristics conducive to measles importation and exportation. (4-6) In a school-based retrospective cohort study during the initial phase of the 2006 outbreak, we demonstrated a vaccine effectiveness of 98.1% in students with one MVCV dose and of 99.4% with two doses. (7) Low or diminishing vaccine effectiveness in older age groups was thus ruled out as an explanation for the outbreak. Here we describe the NRW outbreak in detail, present outbreak-related morbidity and costs in Duisburg (the most severely affected city in NRW), and identify areas for improvement in the national measles elimination strategy. Methods Case definition A case was defined as a person with generalized maculopapular rash [greater than or equal to] 3 days), fever and either cough, coryza of conjunctivitis. (2) Cases that occurred less than one maximum incubation period (18 days) apart in the same city or district were considered to be epidemiologically linked and related to the outbreak. Data collection District public health offices routinely notify measles cases to the Robert Koch Institute (RKI) in Berlin via their state authority. We analysed data from all measles cases during the NRW outbreak and compared the age distribution of these cases with data from 2001. We compared district-level measles vaccination coverage at school entry from 1995 and 2005. (8) All notified patients in Duisburg were contacted to be interviewed with a standardized questionnaire that covered demographic characteristics, clinical symptoms, date of rash onset, measles vaccination status, reasons for non-vaccination, physician consultations and hospitalization, as well as contact details relevant for disease transmission. Interviews were conducted face to face during home visits or by telephone through staff from the district public health office, the state public health institute or the RKI. If at least three attempts to contact the patient by telephone failed, the questionnaire was mailed. Parents were interviewed if the patient was