1. Department of Pathology, Hospital Infantil de México Federico Gómez, Dr. Márquez 162, México, D.F., CP 06720, México
2. Universidad La Salle, Facultad Mexicana de Medicina, México, D.F., México
3. Emergency Room, Hospital Infantil de México Federico Gómez, México, D.F., México
4. Intensive Care Unit, Hospital Infantil de México Federico Gómez, México, D.F., México