Rotaviruses are the most common cause of diarrheal disease among infants and young children. Nearly every child in the world is infected with a rotavirus at least once by the age of five. Immunity develops with each infection, so subsequent infections are less severe. Adults are rarely affected. The most common symptoms of rotavirus infection are severe watery diarrhea, vomiting, fever, and/or abdominal pain. Symptoms usually start about two days after exposure to rotavirus. Vomiting and watery diarrhea can last for three to eight days. There is no specific medicine to treat rotavirus infection. Since rotavirus disease can cause severe vomiting and diarrhea, it can lead to dehydration.