1. Hepatitis Virus Diversity Research Unit, Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of The Witwatersrand, Johannesburg 2193, South Africa
2. Paediatric Clinic, Aliveri, 34500 Island of Euboea, Greece
3. Department of Clinical Virology, Medical School, University of Crete, 71003 Heraklion, Greece