[Prevalence of human immunodeficiency virus infection in drug addicts assisted from 1991 to 1996 at a detoxification center in Castilla y Leon].

BACKGROUND

The Word Health Organization (WHO) has recommended epidemiologic surveillance of infection by the human immunodeficiency virus (HIV) in high risk populations. An important decrease has recently been observed in the prevalence of HIV infection in drug addicts in different regions in Spain with notable differences being found. The evolution of the prevalence of HIV infection in intravenous drug addicts initiating detoxication in Castilla and Leon was analyzed.

METHODS

Six hundred forty-seven drug addicts (535 males and 112 females) were studied over 6 years (1991-1996) analyzing HIV seropositivity, demographic variables, drug use, age of initiation in drug consumption and route used.

RESULTS

Most of the drug addicts were males (83%) with a mean age of initiation in the use of drugs of 19.6 years. Heroine was most frequently consumed in 95% of the patients. The mean length of consumption on admission was 8.6 years with no significant differences being observed in sexes. A relationship was observed between HIV infection and the lower age of initiation in drug usage with the greater the age of admission to detoxication the longer the time having consumed drugs. The prevalence of HIV infection significantly decreased in males and females from 36.8% in 1991 to 17.4% in 1996 (p < 0.0005), with this decrease being related to the change from the intravenous to the smoked route of drug intake. On multivariate analysis by logistic regression the odds ratio at one year of admission was significant (OR = 0.80), years of drug addiction (OR = 1.15), intravenous route (OR = 3.04) and female sex (OR = 2.75).

CONCLUSIONS

A significant decrease has been observed in the prevalence of HIV infection in drug addicts in Castilla and León attending a therapeutic center for detoxication from 1991-1996.