The incidence of pertussis in the Netherlands has remained high since an outbreak occurred in 1996 Neppelenbroek, S E and de Melker, H and Schellekens, J. F.P and Conyn-Van Spaendonck, M A E, Eurosurveillance, 4, 52 (1999), https://doi.org/10.2807/esm.04.12.00052-en