| Institution: | (1) Department of Food and Environmental Hygiene, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 66, 00014 Helsinki, Finland;(2) National Public Health Institute, Helsinki, Finland;(3) National Public Health Institute, Kuopio, Finland;(4) Laboratory Division (HUSLAB), Department of Virology, Helsinki University Central Hospital, Helsinki, Finland;(5) Tampere University Hospital, Tampere, Finland;(6) Centre for Laboratory Medicine, Tampere University Hospital, Tampere, Finland |
