1. Department of Clinical Sciences, Lund University/CRC, Skåne University Hospital, Malmö, Sweden
2. IHRC, Inc, under contract to Polio and Picornavirus Laboratory Branch, Centers for Disease Control and Prevention, Division of Viral Diseases, Atlanta GA, USA
3. Polio and Picornavirus Laboratory Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
4. Kristianstad University, Kristianstad, Sweden
5. Department of Paediatrics, Östersund Hospital, Östersund, Sweden