Officials with the Sibley East School District say that a norovirus is to blame for more than 200 students and staff calling in sick to the district’s elementary school in Gaylord this week. State health officials were called after large numbers of people called in with a severe stomach virus. Sibley East Elementary Principal Mari Lu Martens says that over 200 called in sick on Thursday, but many of those that were out on Wednesday were back in school. The Sibley East elementary and junior high schools were both disinfected, and self-service food offerings have been taken away in hopes of stopping the outbreak. Official test results are due in a couple of weeks. Noroviruses are the leading cause of food-borne illness outbreaks in Minnesota, and are very contagious. Symptoms include vomiting, diarrhea and stomach cramps. The best way to prevent an infection is to wash your hands with warm, soapy water for at least 20 seconds before preparing food or eating and after using the bathroom or changing a diaper.