A number of East Tennessee school systems have closed this week because so many students and teachers were sick.

Three of them--- Union, Monroe, and Roane, will still be closed on Monday. New to the list are Oneida, which will be closed Monday, and Grainger County, which will close Monday and Tuesday.

School leaders blame flu-like symptoms and a stomach virus for most of the absences. While the students are recovering at home, workers worked to clean and sanitize the school in hopes of stopping the spread of sickness.

February is typically peak season for the flu, and Norovirus, commonly known as the stomach bug, is also common this time of year.

Flu season usually ends by April.

Many of you reached out with questions about preventing the spread of illness in schools, and we took your concerns to Dr. Ryan Redman at East Tennessee Children's Hospital.

Question: Are you seeing increase in illnesses in kids?

"Yes. We have started to see an increase in specifically our flu numbers but also other circulating viruses, that are causing everything from respiratory problems to vomiting and diarrhea problems."

Question: Does closing school help?

"Usually when you get a lot of it circulating within a group, it's a good idea to kind of break contact between people so closing schools is an effective strategy. Usually when school does shut down, we do recommend you try to stay away from public places because it doesn't make any sense for them to close down a school if everybody goes to the mall and spreads the viruses amongst themselves there. So usually you want to stay at home as much as possible and just  kind of let everything settle down."

Question: Does cleaning schools help?

"Absolutely. You need to clean the whole area. That's one of the reasons this is helpful for schools. They are able to clear all the hard surfaces of any virus particles that may still be on there. Viruses have a limited life span on hard surfaces. giving that time between where kids are around when you close school, that gives time a chance to kill a lot of these things in addition to a lot of the cleaning agents they are using."

Question: What happens if you come into contact with someone who is sick?

"Making sure you're not touching your eyes or your nose or putting fingers in your mouth. Sharing utensils or drinks. All of that kind of common sense stuff."