Injecting drugs in tight spaces: HIV, cocaine and collinearity in the Downtown Eastside, Vancouver, Canada.

This commentary revisits the political turmoil and scientific controversy over epidemiological study findings linking high HIV seroincidence to syringe exchange attendance in Vancouver in the mid-1990s. The association was mobilized polemically by US politicians and hard-line drug warriors to attack needle exchange policies and funding. In turn, program restrictions limiting access to syringes at the Vancouver exchange may have interfaced with a complex conjunction of historical, geographic, political economic and cultural forces and physiological vulnerabilities to create an extraordinary HIV risk environment: (1) ghettoization of services for indigent populations in a rapidly gentrifying, post-industrial city; (2) rural-urban migration of vulnerable populations subject to historical colonization and current patterns of racism; and (3) the flooding of North America with inexpensive powder cocaine and heroin, and the popularity of crack. In fact, we will never know with certainty the precise cause for the extreme seroincidence rates in Vancouver in the early to mid-1990s. The tendency for modern social epidemiology to decontextualize research subjects and assign excessive importance to discrete, "magic bullet" variables resulted in a counterproductive scientific and political debate in the late 1990s that has obfuscated potentially useful practical lessons for organizing the logistics of harm reduction services - especially syringe exchange - to better serve the needs of vulnerable populations and to mitigate the effects of political-economically imposed HIV risk environments. We would benefit from humbly acknowledging the limits of public health science and learn to recognize the unintended consequences of well-intentioned interventions rather than sweep embarrassing histories under the rug.