1. What type of isolation should the patient be in while in the hospital? 

Enteric isolation. The virus is transmitted by fecal-oral contamination. Strict hand-washing and the use of gloves by health care workers delivering care to patients with gastroenteritis are necessary. Hospital outbreaks of rotavirus infection have occurred when health care workers have transmitted the virus from one patient to another.

2. Why does rotavirus cause a watery diarrhea instead of a bloody diarrhea?

Classic explanation: Rotavirus causes a malabsorptive diarrhea, which can be reduced by stopping oral feedings. The virus causes a blunting and atrophy of small intestinal villi, which results in reduced adsorptive capacity.

New idea (1996). Rotavirus encodes a viral enterotoxin (NSP4). The viral enterotoxin is responsible for the acute diarrhea. (Dr. Mary Estes from Baylor Medical School demonstrated this in an animal model). Rotavirus infection does eventually result in blunting and atrophy of the intestinal villi (this process takes 2-4 days to occur and it can take 2-8 weeks to regenerate effective villi), therefore malabsorptive diarrhea is also a major problem after the initial enterotoxin induced diarrhea.

3. Describe the rapid test for rotavirus detection. 

The enzyme immunoassay (EIA) for rotavirus antigen was positive. This test and latex agglutination are the most common tests used to detect rotavirus. The virus was first discovered in the stools of children with vomiting and diarrhea by using electron microscopy. It was named for its characteristic wheel-like ("rota") morphologic appearance on electron microscopy. However, this technique is not routinely used because of the ease of EIA and latex agglutination. RNA gel electrophoresis can also be used to detect rotavirus in stool specimens, but its use is primarily as a research tool for epidemiologic and vaccine studies. Virus isolation is not routinely performed in a clinical laboratory setting because it is inefficient and too time consuming.

4. What is the best treatment for rotavirus infection?

Effective treatment to date includes aggressive use of intravenous and/or oral rehydration therapy. Oral rehydration is limited to patients without severe vomiting. There is no specific antiviral agent for rotavirus infections. Vaccines for prevention or modification of rotavirus-induced diarrhea are A vaccine for prevention or modification of rotavirus-induced diarrhea has recently been approved (see question 7).

5. Can patients get this infection again?

Yes. Type specific immunity is generated in response to rotavirus infection, which provides partial protection from another infection. However, at least 4 serotypes of rotavirus exist.

6. Are other family members likely to acquire this infection?

Yes, but due to pre-existing immunity, the disease is likely to be much less severe.

7. Is there an effective vaccine to prevent illness? 

A new vaccine (RV-TV for rotavirus-tetravalent) was being evaluated and FDA approved on August 31, 1998. This vaccine was developed by placing the gene encoding the human rotavirus capsid protein of different serotypes into a rhesus rotavirus. All four rotavirus serotypes, are included hence the tetravalent vaccine. In the attached study, the vaccine gave 88% protection against severe diarrhea caused by rotavirus, 75% protection against dehydration and produced a 70% reduction in hospital admissions. The researchers concluded that the quadrivalent rhesus rotavirus – based vaccine induced a high level of protection against severe diarrheal illness caused by rotavirus.

However, this vaccine was withdrawn from use in July, 1999. (See attached article from MMWR). This action was based on reports to the Vaccine Adverse Events Reporting System of Intussception (a type of bowel obstruction that occurs when the bowels folds in on itself) among 15 infants who received rotavirus vaccine.