[Rates of human immunodeficiency virus (HIV) infection in intravenous drug addicts from the Barcelona area, according to sex and age of drug consumption onset].

Background: The differences in the rates of HIV infection in intravenous drug addicts according to the age of onset of drug consumption, sex and length of intake were evaluated.

Methods: The study sample was made up of 650 intravenous drug addicts (535 males and 115 females) admitted to a Hospital Detoxication Unit over 7 years (1987-1993). Of all these patients HIV serology and a questionnaire related to sociodemographic variables and drug consumption (age, sex, year of onset of intravenous drug intake, length of addiction and year of admission) were obtained.

Results: The rate of HIV infection for any length of addiction was higher in females than in males with this difference being significant for a length of addiction of less than 24 months (p = 0.03). The greater the age of onset in the use of intravenous drugs the lower the rate of HIV infection (p < 0.0001). In addiction times of less than 24 months the subjects who began drug consumption at an earlier age than the mean (19 years) presented significantly higher HIV infection rates (p = 0.04).

Conclusions: Among the intravenous drug consumers in the area of Barcelona, Spain subgroups may be found: those who enter the consumption of intravenous drugs early and women, demonstrating high rates of HIV seroprevalence from the onset of their addiction.