In the suburbs of Pittsburgh, Pennsylvania, dozens of schoolchildren were ill unknown disease, resulting in the school have been canceled classes for 800 students, at least until next week.
At first, classes were canceled on Friday after 134 students in middle and elementary schools were identified symptoms similar to the flu.
However, after the Tuesday morning some students threw up in class, the school principal decided to immediately dissolve all the students go home and cancel the rest of the week all the classes.
Preliminary tests showed that the discomfort was not caused by any bacteria and a food poisoning. The analyzes also showed that the virus is "highly contagious" and spread through human contact with contaminated surfaces.