Molecular detection and genotyping of enteroviruses from CSF samples of patients with suspected sepsis-like illness and/or aseptic meningitis from 2012 to 2015 in West Bank, Palestine

Abstract

Background: Human enteroviruses (HEVs) are the most frequently reported cause of aseptic meningitis with or without CSF pleocytosis in childhood. Rapid detection and genotype of HEVs is essential to determine the causative agent and variant causing sepsis-like illness and/or aseptic meningitis.

Aim: To investigate the molecular epidemiology of enteroviruses (EVs) among patients with sepsis-like illness and/or aseptic meningitis admitted to three major hospitals in West Bank, Palestine from 2012 to 2015.

Methods: During the study period, 356 CSF samples were collected from patients with sepsis-like illness and/or aseptic meningitis. Two RT-nested PCR assays targeting a partial part of 5'UTR for direct diagnosis and the VP1 region for genotyping by sequence analysis of the viral genome were used.

Results: HEV RNA was detected in 66 of 356 (18.5%) of CSF samples. Age distribution showed that 64% (42/66) were infants (<1 year), 18% were children between 1 and 5 years old, 12% were children between 5 and 10 years old, and 6% were more than 10 years old. Of the 66 EV cases, 12 were successfully genotyped. Five different EV genotypes were identified. All of them belonged to HEV-B species. The study showed that echovirus 6 genotype accounted for 42% of the sequenced cases. The HEV infections in the present study tended to show slight seasonal pattern with more cases occurring during spring and summer, yet still significant numbers were also reported in fall and winter seasons.

Conclusion: HEV was isolated from a significant number of children with sepsis-like illness and/or aseptic meningitis. In addition, the molecular method utilized for direct diagnosis and genotyping of HEV from CSF revealed that more than one HEV type circulated in the West Bank, Palestine during the study period.

Fig 1. Distribution of HEV cases (red bars) by season compared to total number of cases (blue bars).

Fig 2. HEV cases included in the study (2012–2015) with Ministry of Health-reported sepsis like illness and/or viral meningitis cases and incidence rates (2000–2015).

Fig 3. Phylogenetic consensus tree.

The tree depicts the viral capsid protein 1 (VP1) gene sequences for the 12 HEV isolates in Palestine (red triangle and tagged by their laboratory code and Accession number) along with 22 isolates from GenBank belonging to different geographical areas and genotypes. The tree was reconstructed by the maximum likelihood statistical method and based on the Tamura-Nei method. A bootstrap validation of 1000 replicates and a cut-off value for consensus tree of 75% were used. Polio virus-Sabin strains and HEV 68 were used as an out group.