[1] UNIV CALIF SAN FRANCISCO,DEPT LAB MED,SAN FRANCISCO,CA 94118
[2] IRWIN MEM BLOOD CTR,SAN FRANCISCO,CA 94118
[3] CTR DIS CONTROL & PREVENT,NATL CTR INFECT DIS,DIV HIV AIDS,ATLANTA,GA 30033
[4] UNIV SO CALIF,SCH MED,DEPT MED,LOS ANGELES,CA 90032
[5] UNIV WASHINGTON,DEPT MICROBIOL & MED,SEATTLE,WA 98195