Galveston County Daily News (Internet / Print) 01/18/06 Weekly Column by Dr. Sally Robinson and Dr. Keith Bly: Rotavirus is the most common cause of severe diarrhea in children in the United States, with more than 3 million cases each year and 55,000 hospitalizations of children under age 5 for dehydration resulting from the infection. Rotavirus infections occur most often during the winter months. As with any illness, you can reduce your child’s risk of becoming infected by washing hands frequently, cleaning contaminated surfaces promptly and washing soiled clothing.