1. Department of Paediatrics, Federal University of Bahia School of Medicine, Salvador, Brazil
2. Department of Pathology, Federal University of Bahia School of Medicine and Centro de Pesquisa Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil
3. Virology, University of Helsinki and University Central Hospital, Helsinki, Finland
4. Department of Paediatrics, University of Turku, Turku, Finland