[1] NATL AUTONOMOUS UNIV MEXICO, INST INVEST BIOMED, MEXICO CITY 04510, DF, MEXICO
[2] UNIV AUTONOMA YUCATAN, CTR INVEST REG, DEPT PATOL TROP, MERIDA 97000, YUCATAN, MEXICO
[3] INST MEXICANO SEGURO SOCIAL, UNIDAD INVEST CLIN ENFERMEDADES INFECCIOSAS & PARA, MEXICO CITY 04000, MEXICO
[4] HOSP INFANTIL MEXICO FEDERICO GOMEZ, BACTERIOL INTESTINAL LAB, MEXICO CITY 06720, MEXICO
[5] HOSP GEN OHORAN, SERV URGENCIAS PEDIAT, MERIDA 97000, YUCATAN, MEXICO