[1] MULTICTR AIDS COHORT STUDY, CHICAGO, IL USA
[2] UNIV PITTSBURGH, GRAD SCH PUBL HLTH, PITTSBURGH, PA 15260 USA
[3] JOHNS HOPKINS UNIV, SCH PUBL HLTH, BALTIMORE, MD 21218 USA
[4] UNIV CALIF LOS ANGELES, LOS ANGELES CTY HARBOR MED CTR, TORRANCE, CA 90509 USA
[5] NIAID, BETHESDA, MD 20205 USA
[6] CETUS CORP, EMERYVILLE, CA 94608 USA