DES MOINES, Iowa — The Iowa Department of Public Health says it’s received numerous reports of norovirus illnesses in the past few weeks.

Norovirus cases occur all year but are usually higher in the colder months because people are indoors more and in closer contact.

The virus spreads easily when people don’t stay at home with diarrhea or vomiting and when they don’t wash their hands after going to the bathroom. The illness also spreads when people prepare food while ill with vomiting and diarrhea.

The state medical director, Dr. Patricia Quinlist, says people with diarrhea or have been vomiting should not handle food, no matter how well they wash their hands.

Norovirus symptoms include nausea, vomiting, diarrhea and low-grade fever.