Changes in heroin administration route and frequency of human immunodeficiency virus infection

BACKGROUND: Self-administration of drugs by different intravenous routes may induce a reduction in the organic complications of drug addiction (DA). The aim of this study was to evaluate the changes in the way of drug administration in a series of DA individuals in the province of Cadiz, Spain, and the evolution of the frequency of infection by the human immunodeficiency virus (HIV) in these patients. METHODS: The reports of all the drug users from the province of Cadiz admitted to the Detoxication Unit of the Hospital Punta de Europa in Algeciras, from January, 1989 to July, 1993 were reviewed. At the time of admission many data were evaluated, fundamentally the main route of drug administration, and anti-HIV seropositivity. RESULTS: Seven hundred ten drug users were included in the study. Ninety-seven percent used mainly heroin. The route of drug administration on admission was intravenous in 56.1%, pulmonary in 39.7%, inhalatory in 3.2% and oral in 0.8%. Forty-one point seven percent patients were seropositive for HIV. The frequency of the use of the intravenous route throughout the semesters analyzed was I/89: 85.7%, II/89: 89.6%, I/90: 80%, II/90: 80.8%, I/91: 59.8%, II/91: 50%, I/92: 44.9%, II/92: 39%, I/93: 34.3% (p < 0.00001). The use of the respiratory route significantly increased. The percentage of anti HIV positivity in the drug users evaluated was 67.4, 80.8, 56.4, 46.9, 40.7, 34.1, 30.6, 36.3, 23.2% (p < 0.00001), respectively for the same periods. The decrease in the use of the intravenous route and the reduction in anti HIV seropositivity demonstrated a correlation coefficient of 0.91 with a confidence interval from 0.62 to 0.98 (p < 0.05). CONCLUSIONS: The decrease, over time, in the use of the intravenous route for heroin administration in the collective analyzed was significantly associated with a decrease in HIV infection in these patients.