Enterovirus D68 serosurvey: evidence for endemic circulation in the Netherlands, 2006 to 2016

Background: Enterovirus D68 (EV-D68) has caused major outbreaks of severe respiratory illness world-wide since 2010. Aim: Our aim was to evaluate EV-D68 circulation in the Netherlands by conducting a serosurvey of EV-D68 neutralising antibodies (nAb) among the Dutch general population. Methods: We screened 280 sera from children and adults in the Netherlands and used two independent sets of samples collected in the years 2006 and 2007 and in the years 2015 and 2016, time points before and after the first EV-D68 upsurge in 2010. Neutralisation capacity of the sera was tested against the prototype Fermon EV-D68 strain isolated in 1962 and against a recent EV-D68 strain (genotype B-3) isolated in France in 2016. Results: Regardless of the time of serum collection, we found remarkably high overall seropositivity (94.3-98.3%) for nAb against both EV-D68 strains. Geometric mean titres increased in an age-dependent manner. Conclusions: Our data suggest that EV-D68 has been circulating in the Netherlands for decades and that the enterovirus surveillance does not accurately capture the prevalence of this clinically relevant pathogen.