Summary from abstract by Simon Collins, HIV i-Base

A very useful and timely epidemiology review of research papers on global HIV and IDU by the Reference Group to the UN on HIV and Injecting Drug Use was published in September in the Lancet. [1]

In a systematic search of peer-reviewed, internet, and grey literature databases; and data requests were made to UN agencies and international experts, over 11,000 documents were reviewed, graded, and catalogued.

Injecting drug use was identified in 148 countries but data for the extent of injecting drug use was absent for many countries in Africa, the Middle East, and Latin America. The presence of HIV infection among injectors had been reported in 120 of these countries. Prevalence estimates of injecting drug use could be ascertained for 61 countries, containing 77% of the world’s total population aged 15–64 years. Extrapolated estimates suggest that 15·9 million (range 11·0–21·2 million) people might inject drugs worldwide; the largest numbers of injectors were found in China, the USA, and Russia, where mid-estimates of HIV prevalence among injectors were 12%, 16%, and 37%, respectively. HIV prevalence among injecting drug users was 20–40% in five countries and over 40% in nine.

The researchers estimated that, worldwide, about 3 million (range 0·8–6·6 million) people who inject drugs might be HIV positive.

The authors concluded “The number of countries in which the injection of drugs has been reported has increased over the last decade. The high prevalence of HIV among many populations of injecting drug users represents a substantial global health challenge. However, existing data are far from adequate, in both quality and quantity, particularly in view of the increasing importance of injecting drug use as a mode of HIV transmission in many regions”.

In a separate editorial comment, Kamvar Arasteh and Don Des Jarlais from the Beth Israel Medical Center, New York, highlights the importance of the disturbing trends observed in the article for Asia and eastern Europe. [2]

In China, with the largest estimated population of injecting drug users and an HIV prevalence of 12% in users, HIV infections have been rising. In Vietnam, the prevalence of injecting drug use is estimated at 0·25% with an HIV prevalence of 34%. In Malaysia, the prevalence of injecting drug use is 1·3% with an HIV prevalence of more than 10%.

These estimates reveal large gaps between the numbers of IDUs who access prevention services and HIV testing. In 2007, less than half of IDUs in China had received an HIV test in the previous 12 months and knew their status, only a third reported using a condom during their last sexual intercourse, and only 40% reported using sterile injection equipment the last time they injected.

They concluded that “if HIV-prevention efforts are implemented on a large scale when prevalence is low in injecting drug users, it is possible to avert larger HIV epidemics. Thus it should be an imperative—for both resource-constrained countries and international donors—to implement large-scale evidence-based programmes for HIV prevention wherever there is an indication of a problem with the development of injecting drug use.”

References

1. Mathers BM et al for the 2007 Reference Group to the UN on HIV and Injecting Drug Use. Global epidemiology of injecting drug use and HIV among people who inject drugs: a systematic review . The Lancet DOI:10.1016/S0140-6736(08)61311-2. (Early publication 24 September 2008).
2. Arasteh K. Injecting drug use, HIV, and what to do about it. Comment. The Lancet DOI:10.1016/S0140-6736(08)61312-4. (Early publication 24 September 2008).