RESUMEN
BACKGROUND: The human herpesvirus-6 (HHV-6) may be a cofactor of infection by the human immunodeficiency virus type 1 (HIV-1). However, there are discrepancies with respect to the possible epidemiological relation between both viruses. The aim of the present study was to study the prevalence of infection by the HHV-6 in intravenous drug addicts (IVDA) with and without HIV-1 infection. METHODS: IgG antibodies vs HHV-6 (anti-HHV-6-IgG) were determined by indirect immunofluorescence in 100 IVDA (29 seronegative and 71 seropositive for HIV-1 of which 45 were in stage II and 26 in IV-C1 of CDC) as well as in 100 healthy subjects of a similar age (control group). RESULTS: The prevalence of anti-HHV-6-IgG was much higher in the whole group of IVDA than in the control group and was equal in the IVDA with HIV-1 infection and in those patients without infection. There was no significant difference between the latter and the control group with the same being seen between the IVDA in different stages of HIV-1 infection. CONCLUSIONS: The results of this study suggest the existence of an epidemiological relation between human herpes virus-6 (HHV-6) infection and human immunodeficiency virus -1 (HIV-1). However, infection by the HHV-6 has no relation with the evolutive degree of the HIV-1 infection nor with intravenous drug addiction.