Epidemiological linked cases Imatinib 152459-95-5 (=blue) had a known contact with another case. Patient characteristics Twenty-eight (=43%) of the 65 cases were females. The median age was 6 years (range 7 months to 27 years). Most cases were between 5 and 10 years old (N=19, 29%) (Figure 3). Infants (< 1 year old) accounted for 22% (N=14) and the age group from 10 to 19 years accounted for 18% (N=12) of all the cases. Figure 3 Age distribution of the cases, measles outbreak Ghent, Belgium 2011. Number of measles cases by age group (years). The clinical presentation of measles was milder in children than in adults and infants. Children, till the age of 14, were absent from school for an average of 5 to 7 days. Adolescents and adults were absent for 14 up to 21 days from school or work.

Eight of the 14 infants were hospitalized during the outbreak. The reasons for hospitalization were most often dehydration and fever. No complications such as pneumonia or encephalitis were reported. All but two cases (3%) were unvaccinated. These two cases, 13 and 26 years old, had only received one dose of MMR-vaccine. The reported reasons for not being vaccinated were; personal, often anthroposophic, beliefs (72%, N=47), illness at the time of vaccination without catch-up vaccination (3%, N=2) and too young to be vaccinated (22%, N=14). The day care center The index case was part of a group of 14 infants, between the age of 6 months and 1 year, at a day care center. During the period in which we studied the outbreak one infant was shortly hospitalised for measles.

Seven other infants had been hospitalised, from one up to seven days, in the previous month with symptoms like stomatitis, exhaustion, fever, vomiting or rash. During their hospital stay nobody except our index case, was diagnosed with measles. The index case spread the measles virus to three children and one adolescent while sitting in the waiting room of a GP with an anthroposophic practice. The diagnosis of measles was not made during that consultation, but during a later hospital stay. We found laboratory confirmation of measles infection in all tested infants. For only one infant no sample could be obtained, but this infant had also shown symptoms associated with measles. The attack rate in the day care center is estimated at 100%. Further research into the medical history of parents, family and the staff, including trainees and interns, did not point to a possible source for the children.

None of them reported having had symptoms compatible with measles. The schools The schools offered education to children aged 3 to 12 years. One of the schools also offered secondary school (12-18y). There were a total of 804 pupils in the three anthroposophic Batimastat schools affected in this outbreak. We disturbed a questionnaire to all pupils and received 550 responses (response rate of 68%).