Progression of Human Immunodeficiency Virus Type 1 (HIV-1) Infection among Homosexual Men in Hepatitis B Vaccine Trial Cohorts in Amsterdam, New York City, and San Francisco, 1978–1991

Abstract

The authors evaluated the progression of human immunodeficiency virus type 1 (HIV-1) disease from the date of seroconversion to the development of acquired immunodeficiency syndrome (AIDS) and death among 362 well-documented seroconverters. The participants were homosexual men in hepatitis B vaccine trials in Amsterdam (n = 74), New York City (n = 120), and San Francisco (n = 168). There were significant differences in the proportion of deaths, mean age at seroconversion, and mean age at AIDS diagnosis in the three cohorts, but no significant differences in the reported use of zidovudine and Pneumocystis carinii pneumonia prophylaxis. Overall progression rates did not differ significantly across the cohorts: the median time to the development of AIDS was 122 months, and the median time from the initial AIDS diagnosis to death was 20 months. Multivariate proportional hazards analysis of progression from HIV-1 seroconversion to the development of AIDS found faster progression after June 1989. Multivariate proportional hazards analysis of progression from AIDS to death found younger age at diagnosis, an initial diagnosis of Kaposi's sarcoma, and more recent calendar time to be associated with slower progression. Multivariate proportional hazards analysis of progression from HIV-1 seroconversion to death found older age at seroconversion to be associated with faster progression. The 1987 expansion of the AIDS case definition, improved diagnostic methods, and more conscientious care-seeking behaviors may have resulted in diagnosis of AIDS at an earlier stage of HIV-1 infection, which would shorten the apparent time from seroconversion to progression to AIDS. This would also tend to increase survival after an initial AIDS diagnosis, which was observed in the more recent calendar periods, although such increases could also result from improved treatments and prophylaxis for HIV-1 disease. The time from seroconversion to death, a period not influenced by variations in diagnosing AIDS, lengthened only slightly in recent years.