An outbreak of measles in orthodox Jewish communities in Antwerp, Belgium, 2007-2008: different reasons for accumulation of susceptibles Lernout, T and Kissling, E and Hutse, V and De Schrijver, K and Top, G, Eurosurveillance, 14, 19087 (2009), https://doi.org/10.2807/ese.14.02.19087-en