-- North Carolina health officials have yet to find an explanation for a mysterious illness suspected of contributing to about one-third of students at an elementary school staying home Friday.
Officials said they believe many of the students who were absent stayed home because of the disease that is under investigation.
At least 160 students and 11 staff members of the Shiloh Elementary School in Union County, North Carolina, were out Friday, sending officials from the human services department in Union County into action, according to a department official.
Richard Matens, executive director of Human Services at Union County, said today that not everyone absent likely developed the illness, but the large number of illnesses was troubling. He said only one person had visited an emergency room after exhibiting symptoms but no one had been hospitalized. The symptoms included vomiting and diarrhea.
Tahira Stalberte, chief communications officer for the Union County School District, said school officials knew of 30 children and 10 staff members who had symptoms Friday. She said some of the “absent” students were actually picked up by their parents during the day.
Health officials did not have a definitive number of people who had symptoms, but an online survey from the human services department was made available to those who felt ill over the weekend and it was filled out 179 times, Matens said.
Third-grader Matthew Parola was one of those sickened and told ABC News affiliate WSOC-TV in Charlotte he had been "scared because I thought I had a virus or something."
Matthew was back at school on Tuesday after the holiday weekend.
Matens told ABC News students’ family members have started to also come down with symptoms, suggesting the disease is a virus that can spread from person to person.
"Everything is hinting toward it’s viral in nature ... because family members are getting it," he said.
Matens said the illness has been lasting one to two days on average, but that more people are still getting sick. He said samples had been sent to a lab for examination.
"It’s probably the largest event in a single school that I have seen," he told WSOC-TV.
The elementary school underwent a deep clean over Memorial Day weekend, in an effort to calm the fears of students and staff returning on Tuesday. Matens said about 45 children were absent Tuesday, adding he did not know whether they were all ill or absent for other reasons. There are 500 to 600 students enrolled at the school, according to Matens.
An online survey from the human services department was made available to those who felt ill over the weekend and it was filled out 179 times, Matens said.
Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center, said if all the children got sick at the same time, there could be a "single source" contaminant such as food, which can be tainted with a communicable virus.
Additionally, he said there's a chance that the gastrointestinal norovirus could be the cause of the outbreak because of how quickly it spread and the symptoms of the illness.
"Norovirus is spread very, very readily," said Schaffner, who is not investigating the outbreak. "Some of these kids may have had something that brought them together like a church … that took place outside of the school.”