Discrepancies in viral gastroenteritis diagnosis: an unusual dual reovirus–adenovirus infection case

BACKGROUND: : A variable rate of false-positive results may be observed with commercial assays for the detection of rotavirus and adenovirus antigen in stool specimens, depending on the quality of the reagents and the presence of potentially interfering substances in stool samples. OBJECTIVE: : The present report analyse the discrepant results that could be obtained by the commercially available diagnostic tests and that can mask the reliable viral diagnosis. STUDY DESIGN: : One fecal sample was collected from a hospitalized child aged 6 months with acute watery diarrhea and dehydration. The fecal specimen was processed the same day for the rotavirus and adenovirus antigen detection. RESULTS: : The sample was positive for rotavirus antigen by one-step membrane test based on immunochromatographic assays (ICA) and enzyme immunoassays (EIA) monoclonal test but it was negative by an EIA polyclonal test, polyacrylamide gel electrophoresis (PAGE) and RT-PCR assays. In the other hand, the sample was positive for adenovirus antigen by ICA and EIA adenovirus type 40/41. Finally, the sample showed by PAGE an electrophoretic profile resembled that of reovirus. CONCLUSION: : The use of a wide repertory of diagnosis tests allowed to reach an unusual reovirus–adenovirus type 40/41 dual infection. This case also point out the potential participation of reovirus in the ethiology of the diarrhea illness.