There has been a sharp rise in the number of measles infections in the Netherlands, with 108 cases reported so far this year, according to public health institute RIVM.

Of these, 45 were recorded in the past two weeks, and four primary schools have clusters of infections, the RIVM said. However, there is no question of a nationwide epidemic, the agency said.

The schools most affected by the disease are located in the Amsterdam, Rotterdam, The Hague and Eindhoven health board regions and officials are now carrying out a programme of contact tracing.

The RIVM said some of those infected had contracted the disease abroad and then spread it via unvaccinated contacts. Seventeen of this year’s cases involve people who caught measles during a holiday in Morocco, and three who picked it up in Romania.

There are major epidemics in both countries, the RIVM said, and in Morocco, over 100 people have died.

Measles has been part of the childhood vaccination programme since 1976. Children are vaccinated twice, at the age of 14 months and three years.

The last major outbreak of measles in the Netherlands was in 2013 and 2014, and again, holidays abroad were thought to be responsible.