Contribution of the EuroRotaNet surveillance network to rotavirus strain surveillance in Europe.

Two rotavirus strain surveillance networks operate in Europe: the World Health Organization Global Rotavirus Surveillance Network and the European Rotavirus Network (EuroRotaNet). We describe and appraise rotavirus strain surveillance, with a focus on EuroRotaNet, which has conducted rotavirus strain surveillance since 2007 across 21 European countries. Since EuroRotaNet began, epidemiological and genotype data has been collected on over 90,000 rotavirus-positive specimens. We identified distinct differences in strain distribution across seasons, countries, regions and age cohorts. As infant rotavirus vaccination has been rolled out in some European countries, the EuroRotaNet surveillance network is able to monitor changes in strain type circulation and signs of potential emergence of vaccine escape strains, comparing countries with and without vaccination programs. Despite natural fluctuations in strain distribution, the data show an increase in strain diversity after vaccine introduction, although no strain displacement due to vaccination nor emergence of unusual strains of epidemiologically significance were noted. The EuroRotaNet surveillance network takes a pragmatic approach to surveillance and is not overly prescriptive, creating a wide, engaged and sustainable network.