1. Biological and Health Sciences Center, University of Caxias do Sul, Caxias do Sul, Brazil
2. Department of Pediatrics, Porto Alegre Clinical Hospital, Faculty of Medicine, University of Rio Grande do Sul, Porto Alegre, Brazil
3. Department of Epidemiology, Columbia University, New York, NY
4. Department of Pediatrics, Faculty of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirão Preto, Brazil
5. Department of Public Health, University of Maranhão, São Luis, Brazil