The need for a global understanding of epidemiological data to inform human immunodeficiency virus (HIV) prevention among injecting drug users

Since the 1980s, the injecting of illicit drugs, especially opiates, cocaine and amphetamines, has become a worldwide epidemic, affecting more than 130 countries. Because many injecting drug users (IDUs) share injecting equipment with other IDUs, they are at very high risk of contracting human immunodeficiency virus (HIV) and other blood-borne infections. Using case examples from Asia, Eastern Europe and Africa, we show that only a fraction of the data required to monitor HIV prevention among IDUs is effectively collected. In Asia, considerable work has been done to estimate the size of drug-injecting populations and measure risk behaviours. A few HIV prevalence surveys have also been carried out. In Eastern Europe and the countries of the former Union of Soviet Socialist Republics, the focus of attention has been on the monitoring of service reach and the establishing of infection rates among those seeking services, while reliable estimates of the number of IDUs at risk and, therefore, the proportion of IDUs reached by services, are lacking. In Africa, the main purpose of specific data collection has been to establish the existence of a significant drug-injecting problem. For a comprehensive understanding of the HIV epidemics among IDUs and of the efforts to prevent them, however, all three types of data, on the size and pattern of drug injecting, on service provision and on programme impact, including on risk behaviours and HIV prevalence and incidence, need to be systematically collected. In particular, the monitoring of the coverage of treatment and prevention services for