Detections of rare enterovirus C105 linked to an emerging novel clade, Spain, 2019 to 2024

Abstract

Enterovirus (EV)-C105 is a rare genotype not previously detected in Spain. Between 2019 and 2024, we detected EV-C105 in respiratory samples of five patients, through routine EV surveillance. Three cases had respiratory illness and two were hospitalised for neurological illness. Four of the five sequenced strains belonged to an emerging clade (C1), defined by four novel nonsynonymous mutations in key antigenic epitopes. We recommend reinforced clinical awareness and EV genomic surveillance, including respiratory samples, even when symptoms are neurological.

Keywords: Enterovirus C; acute flaccid paralysis; molecular surveillance.

Figure 1

Bayesian-inferred phylogenetic tree with the most likely time of the most recent common ancestor for enterovirus C105 strains, Spain, 2019–2024 (n = 5)

Figure 2

Alignment of deduced amino acid sequences (n = 296) of the VP1 polyprotein of enterovirus C105 strains, Spain, 2019–2024 (n = 5) with the prototype sequence (JX393302) and sequences of global strains extracted from GenBank (n = 19), 2010–2023, showing only variable sites