[1] UNIV MARYLAND,SCH MED,DEPT MED,DIV GEOG MED,BALTIMORE,MD 21201
[2] UNIV MARYLAND,SCH MED,DEPT PHARM,DIV INFECT DIS & TROP PEDIAT,BALTIMORE,MD 21201
[3] CANADA CTR DIS CONTROL,OTTAWA,ONTARIO,CANADA
[4] UNIV WASHINGTON,SCH MED,DEPT MICROBIOL,SEATTLE,WA 98195
[5] SEDE ORIENTE,FAC MED,MICROBIOL UNIT,SANTIAGO,CHILE