"What are noroviruses? Noroviruses are a group of related viruses that affect the intestinal tract causing gastroenteritis illness. This group of viruses has been also referred to as caliciviruses and Norwalk-like viruses. These viruses are an important cause of gastrointestinal illness throughout the United States, including Illinois." I've been so sick since Tuesday morning. Due to to that reason, I haven't been around my son, Wyatt, for 3 days. Posting in case anyone else lives in Illinois. Hope all is well with all your challenges.