1. Centre for Infectious Diseases and International Health, Windeyer Institute of Medical Sciences, University College London, 46 Cleveland Street, London W1T 4JF, UK.
2. Catedra de Microbiologia, Virologia y Parasitologia, Facultad de Ciencias Medicas, Universidad Nacional de Rosario, Argentina
3. Hospital I. Carrasco de Rosario, Boulevard Avellaneda 1402, 2000 Rosario, Argentina