Filet americain, the Dutch spread for on bread made of raw ground beef, must be frozen for a period of 48 hours to be safe for consumption, particularly by pregnant and people whose immune system has been compromised, the food safety board RIVM warned on Wednesday.

Freezing the popular spread to a temperature of minus 12 would kill the toxoplasmosis parasite that may be present in raw meat and which causes the infection affecting hundreds of people each year.

Cancer patients and pregnant women are particularly vulnerable, the board said, and the infection can lead to premature births, eye disease and brain malformation.

Some 750 people a year get toxoplasmosis and in the case of pregnant women half have babies with congenital diseases. Half of the total number of cases is caused by the consumption of raw meat, and filet americain in particular.

The measure could save some €10m to €30m a year. Freezing the product could bring down health care costs and would also save on special educational facilities for brain-damaged children, the board said.