A measles outbreak is taking place in an area of the Netherlands known as the Dutch “Bible Belt.” The region which is largely comprised of conservative Protestant Christians has 161 reported cases in children, with almost half occurring in the past ten days, the public health institute RIVM said on Monday.

Officials say actual numbers may be higher since not all patients have gone to a doctor to report symptoms. Most of the cases are reported in children between the ages of four to 12 who attend orthodox Protestant schools and are not vaccinated against the disease. Five have been hospitalized, DutchNews.nl reports.

"There is a phrase in the Bible which says intervening is against the will of god," Roel Coutinho, director of the RIVM Centre for Infectious Disease Control, told Xinhua. "Therefore, people choose to let themselves and their children not be vaccinated.”

Measles is a contagious respiratory virus that spreads through coughing or sneezing. Symptoms can be fever, runny nose, cough and body rash. The disease can cause ear infections and pneumonia. Out of every 1,000 children who get measles, one or two will die, according to the U.S. Center for Disease Control.

Most Dutch citizens are vaccinated against measles when they are 14 months old and later when they turn nine years old as part of a national inoculation program introduced in 1979. The current outbreak, which is clustered in schools run by the Dutch Reformed Church, objects to vaccination.

“We are talking about several thousands of unvaccinated children currently at risk of getting measles," Coutinho told Xinhua.

The Dutch “Bible Belt” known as De Bijbelgordel in Dutch, is a strip of land in the Netherlands that stretches across the country from the Veluwe area to Zeeland province inhabited by conservative Protestants. Out of the five children who have been hospitalized, two have pneumonia and two other have meningitis. The symptoms of the fifth child have not been released, DutchNews.nl reports.

This isn’t the first time the Netherlands has experienced a measles outbreak in the “Bible Belt.” Between 1999 and 2000, three children died from the disease, 150 were hospitalized and 3,300 were infected, the Irish Times reports. Since then, the Dutch government started a public awareness campaign in the region about measles vaccination in the region hoping to avoid another epidemic.

“We expect this outbreak to spread again very much as in 1999 – from schools to meetings and other social occasions,” Coutinho said. “The problem is that we are talking about several thousand unvaccinated children currently at risk of getting measles – and one sick child can infect 10 more.”