Utility of Cell Culture‐Based Immunocolorimetric Assay for Detection of Rotaviruses in Fecal Specimens Collected From the Acute Gastroenteritis Children

BACKGROUND: Rotavirus (RV) is the leading cause of severe gastroenteritis in children and is responsible for significant morbidity and mortality in developing and low-income countries. Hence, precise and prompt diagnosis of rotavirus infection is vital for treatment. The currently employed detection methods include rotavirus real-time reverse transcriptase polymerase chain reaction (RT-qPCR) and antigen-capture enzyme-linked immunosorbent assay (Ag-ELISA) which have some known strengths and weaknesses. METHODS: Rotaviruses are difficult to grow in various cell substrates; however, a few cell lines, including MA104, show evident virus growth. Hence, MA104 cell-based immunocolorimetric assay (ICA) was developed, and its sensitivity and specificity were studied with the existing rotavirus detection methods that target the viral antigen or nucleic acid. A total of 84 fecal specimens obtained from acute gastroenteritis children were utilized, and the results of ICA were compared with commercial Ag-ELISA and in-house RT-qPCR. RESULTS: A cell culture-based RV-ICA was successfully standardized and validated with commercial Ag-ELISA and in-house RT-qPCR. The sensitivity and specificity of ICA with commercial Ag-ELISA were found to be 90.7% and 36.6%, respectively. The comparison of RT-qPCR with RV-ICA showed slightly lower sensitivity, that is, 84.3%, whereas increased specificity, that is, 57.1%. The positive predictive value of RV-ICA with Ag-ELISA and RT-qPCR was 60% and 90.7%, respectively. It is well accepted that RT-qPCR is a more sensitive and rapid assay for virus detection due to amplification and quantification of target nucleic acid. However, a cell culture-based ICA has an added advantage over Ag-ELISA and RT-qPCR, due to added possibility of rotavirus isolation from positive fecal specimens. CONCLUSIONS: The standardized cell culture-based RV-ICA supports the detection of live rotaviruses from fecal specimens over the commercial Ag-ELISA and RT-qPCR, thus helps identify samples suitable for rotavirus isolation.