The number of cases of Mexican flu in the Netherlands has exceeded 500 for the first time. In its latest figures, the National Institute of Public Health and the Environment reports 517 cases, over twice last week's total.

Only around 25 percent of those infected contracted the illness in the Netherlands. On Thursday, Belgium reported its first fatality as a result of the flu. So far no deaths in the Netherlands have been attributed to the virus.

The Dutch government has ordered 34 million flu vaccines, which are currently under development: two for every resident.