Drug Injecting and HIV-1 Infection: Major Findings from the Multi-City Study

This chapter, based on the results of the World Health Organization MultiCity Study on Drug Injecting and Risk of HIV Infection, attempts to illuminate similarities and dissimilarities in the characteristics of injectors, in HIV-1 prevalence and in risk behaviours around the world. The findings tend to show that the commonalities manifest in the general characteristics and in the behaviour of drug injectors across the globe far outweigh the differences. Analysis of the data permits the drawing of a profile of the drug injector as likely to be male, aged in the late twenties, having initiated injection at age 19, and being of heterosexual orientation. Further similarities are apparent in frequency of injecting, drugs injected, frequency of sexual intercourse, and frequency of unsafe sexual contact. Based on these facts one would expect to see a corresponding uniform spread of HIV-1 infection. The findings, however, contradict this assumption, since a wide range of HIV-1 seroprevalence was demonstrated. The spread of low, middle and high prevalence cities prompts the examination of factors that may be playing a prominent role in the spread of HIV-1, which is explained in later chapters.