Molecular epidemiological study of HEV-B enteroviruses involved in the increase in meningitis cases occurred in Spain during 2006.

Human enteroviruses are one of the main etiological agents of aseptic meningitis and other central nervous system infections, particularly the serotypes included in the enterovirus B species. Molecular methods have proved useful to identify serotypes in clinical samples, facilitating the epidemiological study of these viruses. In the spring of 2006, there was a significant increase in meningitis cases caused by enteroviruses in Spain. In the present study, 138 enteroviruses directly detected in clinical samples of patients with aseptic meningitis (n = 116) and other neurological pathologies (n = 22) received by the National Center for Microbiology during the year, were genotyped by amplification and sequencing part of the VP1 region and phylogenetic analysis. Echovirus 30 was the most frequent serotype, followed in decreasing order by echovirus 6, 9, 13, 18, enterovirus 75, coxsackievirus A9, echovirus 11, 14, 29, 4, and coxsackievirus B4 and B5. Phylogenetic analysis with all Spanish echovirus 30 strains detected in 2006 and other reported echovirus 30 sequences, demonstrated that Spanish strains formed a new lineage, different from others previously described. In conclusion, echovirus 30 is the most commonly reported enterovirus serotype associated with aseptic meningitis in Spain. Direct molecular typing of clinical samples also allows rapid identification of the serotypes involved in an epidemic alert and phylogenetic analysis in the 3'-VP1 region is useful to study viral epidemiology.