Faculty Bibliography

"Intravention," prevention activities that are conducted by and sustained through ongoing actions of members of communities-at-risk, is an appropriate goal for HIV intervention activities. Data from 120 injection drug users in a Brooklyn, New York, neighborhood that has seen decreases in HIV prevalence among IDUs and little HIV diffusion to young adults indicate that most of them have recently (3 months) urged other people to engage in one or more self-protective actions. These data suggest that the common image of IDUs as simply being sources of social and medical problems is inaccurate. Research is needed into how to create and diffuse "communities of intravention; " and we suggest that behavioral interventions be evaluated for their success or failure at creating outward-focused health communication by participants as well as for their impact on individual risk behaviors.

This article estimates the population prevalence of current injection drug users (IDUs) in 96 large US metropolitan areas to facilitate structural analyses of its predictors and sequelae and assesses the extent to which drug abuse treatment and human immunodeficiency virus (HIV) counseling and testing are made available to drug injectors in each metropolitan area. We estimated the total number of current IDUs in the United States and then allocated the large metropolitan area total among large metropolitan areas using four different multiplier methods. Mean values were used as best estimates, and their validity and limitations were assessed. Prevalence of drug injectors per 10,000 population varied from 19 to 173 (median 60; interquartile range 42-87). Proportions of drug injectors in treatment varied from 1.0% to 39.3% (median 8.6%); and the ratio of HIV counseling and testing events to the estimated number of IDUs varied from 0.013 to 0.285 (median 0.082). Despite limitations in the accuracy of these estimates, they can be used for structural analyses of the correlates and predictors of the population density of drug injectors in metropolitan areas and for assessing the extent of service delivery to drug injectors. Although service provision levels varied considerably, few if any metropolitan areas seemed to be providing adequate levels of services.

Issues of cost and complexity have limited the study of the population sizes of men who have sex with men (MSM) and injection drug users (IDUs), two groups at clearly increased risk for human immunodeficiency virus (HIV) and other acute and chronic diseases. We developed a prototypical, easily applied estimation model for these populations and applied it to Miami, Florida. This model combined HIV prevalence estimates, HIV seroprevalence rates, and census data to make plausible estimates of the number and proportion of MSM and IDUs under a number of assumptions. Sensitivity analyses were conducted to test the robustness of the model. The model suggests that approximately 9.5% (plausible range 7.7%-11.3%) of Miami males aged 18 years or older are MSM (point estimate, N = 76,500), and 1.4% (plausible range 0.9%-1.9%) of the total population aged 18 years or older are IDUs (point estimate, N = 23,700). Males may be about 2.5 times more likely than females to be IDUs. The estimates were reasonably robust to biases. The model was used to develop MSM and IDU population estimates in selected urban areas across Florida and should be replicable in other medium-to-large urban areas. Such estimates could be useful for behavioral surveillance and resource allocation, including enhanced targeting of community-based interventions for primary and secondary HIV prevention.