Upsurge of Enterovirus D68, the Netherlands, 2016

Abstract

In June and July 2016, we identified 8 adults and 17 children with respiratory enterovirus D68 infections. Thirteen children required intensive care unit admission because of respiratory insufficiency, and 1 had concomitant acute flaccid myelitis. Phylogenetic analysis showed that all of 20 sequences obtained belong to the recently described clade B3.

Keywords: EV-D68; enterovirus; flaccid quadriplegia; infectious disease outbreaks; infectious myelitis; respiratory insufficiency; the Netherlands; viruses.

Figure 1

Respiratory enterovirus infections, University Medical Center Graningen, the Netherlands, 2014, 2015, and 2016. The total numbers of respiratory specimens tested for enterovirus in these years during April–July were 784, 828, and 871, respectively. Seventeen (2.2%) of 784 were positive for enterovirus in 2014, 5 (0.6%) of /828 in 2015, and 33 (3.8%) of /871 in 2016. Six (35%) of 17 were typed as enterovirus D68 in 2014, versus 0 of 5 in 2015, and 25 (76%) of 33 in 2016.

Figure 2

Maximum-parsimony tree of partial viral protein 1 sequences of enterovirus D68 (EV-D68). Included are the strains obtained in the laboratory of the University Medical Center Groningen (Groningen, the Netherlands) in 2014 (light gray, n = 23) and 2016 (black, n = 20) and worldwide isolates from 2014 (dark gray, n = 73). Recent strains cluster in the recently described clade B3, with a nucleotide divergence of 2.1% within clade B3, 5.5% to clade B1, and 7.3% to clade B2. Clades are according to Tokarz et al. and Gong et al (7,8). We submitted the 20 sequences we obtained during 2016 to GenBank under accession nos.: KX685066–KX685084 and KX710328. CHN, China; DNK, Denmark; ESP, Spain; FIN, Finland; FRA, France; GER, Germany; IRL, Ireland; ITA, Italy; NLD, the Netherlands; SVN, Slovenia; USA, United States. White circles indicate reference strains (n = 2).