MANHATTAN— State and Riley County health officials continue working to determine why dozens of Manhattan High School students are getting sick at school.

Since the first week of school more than 120 students and staff at the school have been sent home due to reports of nausea and vomiting.

The first cases were reported from Manhattan High’s West Campus last week.

The county health department did not find similar illnesses at other area schools.

Parents of sick students are being asked by to provide stool samples to the Riley County Health Department, located at 2030 Tecumseh Rd. in Manhattan.

School officials are also asking students who get sick to stay home for an additional 24 hours after symptoms go away.

Principal Greg Hoyt said in a note to parents that the school nurse reported she had sent more students home from school with vomiting and related symptoms than she ever had in her many years of experience.