Detection of enteroviruses in clinical samples of patients with aseptic meningitis by rapid antigen detection assay

Abstract

Introduction. Human enteroviruses represent the most common etiological agents of aseptic meningitis. Rapid diagnosis of aseptic meningitis affects the management of patients. Objective. The aim of this work was to assess the efficacy of rapid antigen detection (RAD) assay for the confirmation of human enteroviruses in comparison to that of the conventional cell culture (CCC), and to identify the serotypes associated with aseptic meningitis cases in the Autonomous Province of Vojvodina. Methods. RAD assay was carried out using centrifugation of inoculated Vero, RD and HEp-2 cell cultures and indirect immunofluorescence with Pan-Enterovirus 2E11 reagent (Millipore-Chemicon). CCC was performed using the same type of cells and the same immunofluorescence reagent for enterovirus confirmation. Results. Out of 70 analyzed samples (29 cerebrospinal fluid specimens, 27 stool specimens, 9 rectal and 5 throat swabs) , 36 (51.4%) were positive by immunofluorescence after CCC and 34 (48.6%) by the RAD assay. The sensitivity of RAD assay was 94.4% and specificity 100%. Detection time of enteroviruses by the RAD assay was 3 days, and by CCC varied from 3 to 13 days (mean time 6.1 days). Within 72 h from inoculation, a cytopathic effect (CPE) occurred in only 19 (47.5%) of 40 CPE positive samples. Serotyping revealed 11 types of enteroviruses: coxsackievirus A16, B3, B4, B5, and echovirus 2, 4, 6, 11, 13, 16 and 30. Conclusion. The RAD assay was slightly less sensitive than CCC and significantly shortened the detection time of enteroviruses, so it may be useful in rapid diagnosis of enteroviral meningitis.