Faculty Bibliography

Although European and Australian studies of syringe exchange programs have reported safer injection among participants and no increase in drug use, the generalizability of these findings to the US is uncertain. We report on the operations and potential effectiveness of the longest-operating syringe exchange in the US and compare our results to studies of exchange programs outside the US. The sample of 204 study subjects reported no change in the frequency of injection, from 155 to 152 injections per month, and a decline in the frequency of unsafe injections, from 56 to 30 times per month, while participating in the program. In all studies, participants report reduction in unsafe injections, and no increase in illicit drug use. However, the comparison also suggests that a high proportion of Tacoma exchangers have higher initial rates of drug injection, unsafe injection and homelessness, all of which were associated with unsafe injection while using the exchange. These indicate a need for additional services but that the Tacoma program is no less effective than European and Australian programs.

Recent cases of 'AIDS-like' CD4 lymphocytopenia in the absence of HIV infection have generated considerable scientific and public interest. We studied CD4 cell counts and percentages from 1984 to 1992 among 1,246 HIV-seronegative injecting drug users in New York City, a population at very high risk for exposure to bloodborne pathogens. Severe CD4 lymphocytopenia was rare, and there was no evidence of an increase over time. Of 229 subjects with longitudinal data, only four met the surveillance definition for 'idiopathic CD4 lymphocytopenia' (ICL). CD4 cell counts of < 500 cells/microliters were, however, associated with subsequent HIV seroconversion (12.7/100 person-years at risk, relative risk (RR) = 4.53, 95% exact binomial confidence interval (CI) 1.7-10.7, p = 0.002)