Rotavirus infection produces a spectrum of responses that vary from subclinical infection, to mild diarrhea, to a severe and occasionally fatal dehydrating illness.
Rotavirus is the major cause of nonbacterial gastroenteritis, especially in infants and very young children (6 months-2 years of age). The shedding of rotavirus in feces is fairly common among asymptomatic neonates.
In temperate climates, rotaviral infections are seasonal; they peak in frequency during the winter months and are uncommon during the summer. Rotaviral gastroenteritis has sometimes been called “winter vomiting disease.” The disease is characterized by diarrhea of acute onset and a duration of 4 to 8 days. Vomiting is often the initial symptom. Some patients experience vomiting without diarrhea.
Peak viral counts are reported to occur on days 3 to 5 after onset of symptoms. The virus is eliminated from the infected individual within a few days following acute infection. Specimens collected 8 days or more after onset of symptoms may not contain enough rotavirus antigen to produce a positive reaction.
Stool specimens should be collected as soon after onset of symptoms as possible.
This assay does not preclude the presence of other pathogenic organisms. While the relationship between rotavirus and gastroenteritis is well established, coinfection with bacterial pathogens is possible. Bacterial testing should be performed in parallel with the rotavirus antigen test to rule out bacterial etiology of the illness.
Results of the rotavirus antigen assay must be interpreted with caution. A negative result does not exclude the possibility of rotavirus infection, as too small a quantity of virus or inadequate or improper sampling may cause a false-negative result.
Rotavirus Ag in stool is done daily in metra labs with high accuracy.