Gastroenteritis - Viral Diagnostics

Laboratory Tests and Ancillaries

Laboratory testing in acute gastroenteritis is not routinely done. Certain lab exams may be done when the underlying diagnosis is unclear. A stool culture should be considered in those with high fever and bloody diarrhea. Laboratory assays or fecal sampling may be done for possible viral causes in symptomatic patients. A complete blood count (CBC) and blood culture should be considered if suspecting sepsis. Lab testing may also be necessary for surveillance. The most widely used assays for viral pathogen detection are the following: Electron microscopy, enzyme immunoassay, latex agglutination, gel electrophoresis, viral culture (especially for detection of enteric adenovirus, enterovirus, parechovirus, and cytomegalovirus), polymerase chain reaction (PCR), reverse transcription-PCR, and nucleic acid amplification test. A freshly obtained stool sample is preferred for identification of the offending pathogen. Serum electrolytes (eg bicarbonate, sodium), creatinine and glucose may be useful in assessing moderate to severe dehydration, especially in patients who require intravenous (IV) or nasogastric (NG) fluids. This may also be done in patients whose histories and/or physical findings are inconsistent with their diarrheal episodes.