Injection Drug Use and Emerging Blood-Borne Diseases

To the Editor.  —Injection of illicit psychoactive drugs is important as an ecological niche for worldwide diffusion of "emerging" blood-borne pathogens, particularly those for which infection leads to a chronic carrier status. Illicit drug injection has now been reported in 118 different countries,¹ a substantial increase over the 80 countries known to have had illicit drug injection in 1989.² Contrary to popular stereotypes, many injection drug users (IDUs) travel widely, including internationally. The international diffusion of IDU includes spread to geographically remote areas—such as South American and Southeast Asian rain forest areas—where local inhabitants may have contact with animal reservoirs for emerging diseases.Human immunodeficiency virus type 1 (HIV-1) is the best-known emerging virus, and HIV-1 infection has been reported among IDUs in 80 different countries.¹ This is a substantial increase over the 52 countries known to have had HIV-1 infection among IDUs in 1989.²