A further 147 cases of measles were reported last week, bringing the total to 613, the public health institute RIVM said on Thursday.

The outbreak, which began in May, has also spread to four new local authority health services, including Utrecht and The Hague.

Among the new cases are two healthcare workers who probably contracted the disease during their work. Several hospitals in the affected regions and with low take-up of vaccination are now taking preventative measures.

The RIVM expects a falling-off of cases during the summer holiday and for the outbreak to reach its peak after the summer.

Bible Belt

Most of the cases are in the Bible Belt region where staunchly Protestant communities do not vaccinate their children on religious grounds.

Last week, prime minister was criticised by ministers in the orthodox Dutch Protestant church for saying: ‘God never meant these children to suffer because He also ensured there are vaccines.’