Appendix Figure. Cases of measles investigated, by date of onset of symptoms, cluster, and measles virus strain, the Netherlands, June 1–October 16, 2008 (n = 99). D8 indicates the outbreak strain (MVi/Den Haag.NLD/25.08, accession no. EU878303). Association of cases with attendance at schools, camps, and daycare centers: red, schools A and B, The Hague, the Netherlands; orange, anthroposophic summer camp C, Drenthe, the Netherlands; light green, anthroposophic summer camp D, Switzerland; yellow, anthroposophic summer camp E, France; pink, child day care center F, Utrecht, the Netherlands; dark green, child day care center G, Utrecht; gray, unknown.