1Department of Pediatrics, Faculty of Medicine, Federal University of Bahia, Brazil 2Professor Hosannah de Oliveira Pediatric Center, Federal University of Bahia, Brazil 3Aliança Hospital, Salvador, Bahia, Brazil 4Central Laboratory of Bahia, Salvador, Bahia, Brazil 5Bacteriology Division, Adolfo Lutz Institute, São Paulo, São Paulo, Brazil 6Pan American Health Organization, Washington DC, USA