Several thousand children in eastern Germany have fallen sick. The exact cause of the outbreak remains unknown, but a food-borne virus is suspected.
More than 6,000 students and preschoolers, as well as few teachers, have been affected by a diarrhea and vomiting bug.
The first reports of the gastroenteritis began surfacing on Tuesday. By Friday, there were reported illnesses in five of Germany's 16 states.
The ill have not suffered any further complications.
"All the institutions which have registered cases of the illness so far are probably being provided by the same caterer," wrote the Robert Koch Institute, which researches and advises the German health ministry on infectious diseases. "This suggests that it is an outbreak caused by food."
It remains unclear whether the norovirus, salmonella bacteria or a natural toxin is responsible for this wave of illness, the largest gastrointestinal disease wave to hit Germany in years.
The affected German states include Saxony, Thuringia, Berlin, Brandenburg
Authorities have set up a regional taskforce to tackle the problem and prevent it from spreading.
tm/mr (dpa, Reuters)