Summary of research findings through 2013:

Who did we reach?

  • UFO participants are all recruited by street-based outreach in locales and neighborhood throughout San Francisco where young IDU hang out
  • 1505 young IDU were screened and interviewed between 2000-2013
  • 965 were hepatitis C negative and invited to participate in follow-up study
  • The average age of the participants was 23 years old;
  • The majority (70%) were male
  • Only 28% reported stable housing in the prior 3 months

Injection drug use

  • IDU in UFO had been injecting on average for 5 years
  • More than one-third (35%) reported daily injection drug use in the last 30 days with a median of 3 injections per day
  • 78% had ever shared a syringe
  • Nearly half (42%) borrowed a used syringe in the prior 3 months
  • 76% had shared other injecting equipment, such as cookers or rinse, in the last 3 months
  • 76% used at least 1 of several needle exchange venues in the last 30 days

Drug treatment

  • Almost two-thirds (65%) had a history of drug treatment
  • Only 16% had participated in drug treatment in the prior 3 months

Hepatitis C

  • Almost half (35%) of young IDU screened by UFO have antibodies to HCV, indicating previous or current infection
  • HCV incidence is very high: 27% per year
  • 20% of young IDU who get infected with HCV spontaneously resolve the infection, but many of these get re-infected


  • HIV prevalence is lower than HCV prevalence at 4%
  • The majority (89%) of HIV infections detected in UFO participants are in males
  • HIV prevalence was highest among male IDUs who have sex with men

Hepatitis B

  • 21% had been infected with HBV
  • HBV immunizations are still needed among young IDU:
  • Only 22% of participants had been previously vaccinated
  • More than half (56%) were susceptible and could benefit from vaccine

Gender differences

  • Female IDUs were significantly younger than males (21 vs 24)
  • Females were more likely to engage in needle borrowing, sharing cookers or rinse, and being injected by someone else
  • Females were more likely than males to report recent sexual intercourse and to have IDU sex partners


  • Most (85%) young IDU had a history of incarceration (jail or prison)
  • Of those, 36% had been incarcerated in the last 3 months
  • HBV and HCV infections were significantly higher among those with any history of incarceration (29% and 42% respectively) compared with those with no incarceration history


  • 16% reported a heroin overdose in the last 3 months
  • Three-fourths (73%) had ever witnessed a heroin-related overdose, and half (50%) had witnessed an overdose in the last 12 months
  • 14% of those who had witnessed an overdose in the past year