Early Diagnosis of Enteroviral Meningitis by a Solid-phase Reverse Immunosorbent Test and Virus Isolation

Abstract

45 cases of aseptic meningitis/meningoencephalitis were studied with regard to enteroviral etiology by virus isolation and solid-phase reverse immunosorbent test (SPRIST), a cross-reacting test for enterovirus IgM. An etiological diagnosis was reached in 37/45 (82%) patients. Etiological diagnoses other than enteroviruses were found in 8 patients: Borrelia burgdorferi in 4, varicella-zoster virus in 2, herpes simplex virus in 1 and mumps virus in 1 patient. Enteroviruses (echovirus 6, 21 and 30) were isolated from cerebrospinal fluid (CSF) in 26/37 (70%) and from stool samples of 20/21 (95%) of patients with no other etiology. Altogether enteroviruses were isolated from CSF and/or faecal samples in 29 patients. Echovirus 30 dominated as etiologic agent. In 34/40 (85%) of the samples with an enterovirus, a cytopathogenic effect was observed in cell culture within 4 days. In patients with an enterovirus isolate a SPRIST IgM response to echovirus 3, 5, 7 and/or coxsackievirus B3 was detected in 6/13 (46%) sera sampled 3-4 days after the onset of meningeal symptoms and in altogether 17/25 patients (68%). In 4 out of these virus isolation positive and SPRIST negative patients a single serum for SPRIST was available less than 4 days after onset of meningeal symptoms. Antigen from echovirus 5 gave the highest diagnostic yield. The SPRIST IgM test was positive in 2 cases where virus isolation, complement fixation and neutralization tests were negative. Epidemiological data however supported an enteroviral diagnosis in both of them. In conclusion, both SPRIST and virus isolation seem to be valuable for the early diagnosis of enteroviral meningitis.