When a person is infected with a rotavirus, symptoms may include diarrhea, high fever, and lack of appetite. Diarrhea is probably the most dangerous of the symptoms, since it can lead to dehydration. Not everyone who is infected with the virus will develop symptoms. Possible symptoms of rotavirus infections are sometimes seen with other medical conditions.
When a person becomes infected with rotavirus, it begins to multiply within the small intestine. After approximately two days, rotavirus symptoms can begin. This period between the rotavirus transmission and the start of symptoms is called the "rotavirus incubation period."
Not all people who are infected with the virus will develop symptoms. If symptoms do occur, the illness tends to begin suddenly. Common rotavirus symptoms include:
- Upset stomach
- Watery diarrhea
- Severe dehydration
- High fever (greater than 102.2°F)
- Loss of appetite
- Mucus in stool.
The watery diarrhea can be mild to severe and generally will last for three to nine days. Severe diarrhea can lead to a dangerous depletion of body fluids called dehydration, which can result in death if untreated. Virtually all children become infected with rotavirus in the first three to five years of life, but severe diarrhea and dehydration occur mainly among children aged 3 to 35 months.
Symptoms of rotavirus often occur with upper respiratory infections, such as the common cold, although scientists are not sure of the connection.
In the United States and other countries with a temperate climate, rotavirus has a winter seasonal pattern, with annual epidemics occurring from November to April. Rotavirus infections tend to start in the west and spread east, starting in California and ending in New England. In tropical areas, rotavirus infections occur year-round, increasing slightly during the cooler, rainy season.