Almost 5,800 cases of whooping cough were recorded in the Netherlands in the first five months of the year, a sharp increase on previous years, the public health institute RIVM says.
In a normal year, between 2,400 and 9,000 children and adults are diagnosed with whooping cough, which can be fatal for very young children.
Doctors in particular should be alert to the symptoms, director Roel Coutinho said using microblogging service Twitter.
Whooping cough first manifests itself as a cold which turns into a deep cough in the third and fourth weeks. The infection usually lasts around six weeks.