Is cytomegalovirus infection a co-factor in HIV-1 disease progression?

The influence of cytomegalovirus (CMV) infection as a co-factor in HIV-1 di sease progression has mainly been studied in haemophiliacs and remains cont roversial. Based on the files of 1683 HIV-1-infected patients in the Seropo sitive Cohort (SEROCO) and Haemophiliacs Cohort (HEMOCO) cohorts, we studie d the role of CMV infection in progression to CD4(+) cell counts of less th an 200 mul, AIDS onset and death, in various HIV exposure groups. Adjusted relative risk (aRR) of progression to AIDS and to death was respectively 1. 30 (P = 0.05) and 1.58 (P = 0.007). In the sexual exposure group the influe nce of CMV infection on the risk of progression to AIDS was of borderline s ignificance (aRR = 1.50; P = 0.07) and was more marked on the risk of death (aRR = 2.00; P = 0.03). No such influence of CMV infection was observed in the transfusion and intravenous drug use exposure groups. When we studied the influence of CMV infection according to the stage of HIV disease, the m ain effect was on progression from AIDS to death, probably because CMV dise ase is a late event. Sexual CR;IV transmission and frequent re-exposure to CMV may explain why CMV infection emerged as an important co-factor for HIV progression only in the sexual exposure group.