An official website of the United States government
Here's how you know
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Figure 1 Prevalence of HIV infection among young injecting heroin users in two cross sectional studies carried out in Barcelona, Madrid, and Seville in 1995 and 2001–2003, by time since first injection.