A nasty stomach flu swept through Carroll Elementary School in the Dallas suburb of Frisco making 60 students sick Wednesday, 170 on Thursday and 350 sick or staying away from school Friday to avoid the diarrhea, stomach cramps and vomiting, nbcdfw.com in Dallas reported.
Since so many children were getting sick in school, Principal Melissa Longfellow said staff and teachers, who were also getting sick, helped with clean up.
However, cleaning crews were assigned to sanitize surfaces at the school to make it ready for Monday.
The health department had not recommended closing the school, because the 24-hour virus seemed to be running its course.
Norovirus, a very contagious virus, can come from an infected person, contaminated food or water, or by touching contaminated surfaces.
The virus causes the stomach or intestines or both to become inflamed causing stomach pain, nausea and diarrhea.