Antibodies to the human immunodeficiency virus in needles and syringes used by intravenous drug abusers

The sharing of needles and syringes by intravenous drug abusers has been recognized as a critical factor in the transmission of the human immunodeficiency virus (HIV). In an attempt to reduce the sharing of needles and syringes among intravenous drug abusers, a pilot sterile needle-and-syringe exchange programme was established in an inner city neighbourhood in Sydney. The contents of exchanged syringes were screened for antibody to HIV by the enzyme-linked immunosorbent assay (ELISA); reactive and borderline samples were tested further by the Western Blot method. Of a sample of 300 needles-and-syringes that were exchanged, three (1%) needles-and-syringes were confirmed as containing antibody-seropositive blood by both ELISA and Western Blot methods and thus as being potentially infectious. As only 70% of known positive-control syringes were detected in this study, the proportion of potentially infectious needles-and-syringes that was found may have underestimated the proportion of infectious injection equipment that was returned. These findings highlight the importance of the removal of used needles and syringes from circulation in addition to the supply of sterile equipment. This method of monitoring exchanged needles-and-syringes is suggested as a means to evaluate measures that are designed to reduce the transmission of HIV among intravenous drug abusers. The rapid implementation of sterile needle-and-syringe exchange programmes is imperative to stem the spread of HIV infection.