Case report: Clinical and virological characteristics of aseptic meningitis caused by a recombinant echovirus 18 in an immunocompetent adult

Abstract

Echovirus 18 has been recognized as an important causative pathogen of aseptic meningitis in young children worldwide, and echovirus 18-induced meningitis is rarely found in adults with immunocompetence. In this case study, we report the clinical and virological characteristics of aseptic meningitis caused by recombinant echovirus 18 in an adult with immunocompetence. A 31-year-old woman with immunocompetence was admitted to our hospital with fever, dizziness, severe headache, nausea, and vomiting for the past 1 day and was diagnosed with viral meningitis based on the clinical manifestations and laboratory results from cerebrospinal fluid (CSF). The patient received antiviral treatment with ribavirin and interferon as soon as the enterovirus infection was identified using qRT-PCR and was cured after 4 days. From the oropharyngeal swab and CSF samples, two echovirus 18 strains were isolated with a single nucleotide difference located at the 5′ UTR. Phylogenetic analyses based on the VP1 gene showed that the two strains belonged to the subgenotype C2 and were clustered with sequences obtained from China after 2015, while the results from the 3D polymerase region showed that the two strains were closely related to the E30 strains. Bootscanning results using the 5′ UTR to 2A region and the 2B to 3′ UTR region showed that potential intertypic recombination had occurred in the 2B gene. Recombination analyses further confirmed that the two strains (echovirus 18) presented genome recombination with echovirus 30 in the nucleotide regions of the 2B gene. To the best of our knowledge, this is the first report of echovirus 18-induced meningitis in an adult with immunocompetence from mainland China, highlighting the need for close surveillance of echovirus 18 both in children and adults in the future.

Metatranscriptomics revealed the molecular characterization of circulating enterovirus strains causing aseptic meningitis in children in Wuxi, China

“…Recombination, which is very common in enteroviruses like E18, has significant impacts on aspects such as viral evolution, transmission, and virulence [ 21 ]. Our detected CHN/WX/CSF14 strain is closely related to LJ/0530/2019, first isolated from an immunocompetent adult with aseptic meningitis [ 18 ]. This strain was a recombinant with a 2B gene mosaic from echovirus 30.…”

“…In 2015, an E18 associated encephalitis/meningitis was first reported in Hebei, China [ 17 ]. To date, at least 10 provinces have reported circulating E18, with some documented small-scale outbreaks [ [18] , [19] , [20] ]. Generally, circulating E18 strains in China cluster within the C2 subgroup [ 19 ].…”