The rotavirus is a round-shaped virus under the electron microscope, which is the main cause of severe dehydration diarrhea and vomiting in young children aged 6 to 24 months in the world. It is the most dangerous for the youngest baby. Almost all children are infected with rotavirus before the age of 5. Rotavirus can cause enterovirus infection, causing fever, vomiting and severe diarrhea and dehydration. Severe cases can cause vomiting or diarrhea more than 20 times a day. Symptoms usually last 3 to 9 days. Rotavirus is highly contagious and is usually transmitted through the fecal-oral route (eg, ingesting contaminated food and water, exposure to contaminated surfaces such as toys); infection may even occur in well-sanitized locations.