HIV seroconversion in intravenous drug users in San Francisco, 1985-1990

AIDS. 1994 Feb;8(2):223-31. doi: 10.1097/00002030-199402000-00010.

Abstract

Objective: To examine the HIV seroconversion rate, risk factors for seroconversion, and changes in risk behavior over time in intravenous drug users (IVDU) in San Francisco, 1985-1990.

Design: Observational study.

Setting: All methadone maintenance and 21-day methadone detoxification programs in San Francisco.

Participants: A total of 2351 heterosexual IVDU, of whom 681 were seronegative at first visit and seen at least twice ('repeaters').

Main outcome measures: HIV seroconversion rates, risk factors for seroconversion, and changes in behavior.

Results: The HIV seroconversion rate in repeaters was 1.9% per person-year (ppy) of follow-up [2.1% in women versus 1.7% in men (not significant); 4% in African Americans versus 1% in whites (P = 0.006); 3.9% ppy in the first third of the study, 1.2% in the second (P = 0.007), and 1.9% in the last (not significant)]. Risk factors for seroconversion were five or more sexual partners per year [hazard ratio (HR) = 2.6; P = 0.02], use of shooting gallery ever (HR = 2.9; P = 0.02), and less than 1 year (lifetime) in methadone maintenance (HR = 2.7; P = 0.02). Self-reported intravenous cocaine use fell from 33 to 15% over 5 years, shooting gallery use fell from 19 to 6%, and the proportion with five or more sexual partners fell from 25 to 10%. Bleach use rose to 75% of needle-sharers.

Conclusions: The 1985-1990 HIV seroconversion rate in IVDU (1.9% ppy) was comparable to that in San Francisco cohorts of homosexual men (1.4% ppy). A decline in HIV seroconversion coincided with changes in risk behavior. Stable attendance of methadone maintenance was highly protective: the seroconversion rate in subjects with 1 year or more in methadone was 12% ppy.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Amphetamines
  • Bias
  • Cocaine / administration & dosage
  • Cohort Studies
  • Comorbidity
  • Disinfection
  • Equipment Contamination
  • Ethnic Groups
  • Female
  • HIV Infections / prevention & control
  • HIV Infections / transmission
  • HIV Seropositivity / epidemiology*
  • HIV Seroprevalence / trends
  • Heroin Dependence / epidemiology
  • Heroin Dependence / rehabilitation
  • Humans
  • Injections, Intravenous / adverse effects
  • Male
  • Needle Sharing
  • Risk Factors
  • San Francisco / epidemiology
  • Sexual Behavior / statistics & numerical data
  • Sexual Partners
  • Sodium Hypochlorite
  • Substance Abuse Treatment Centers
  • Substance Abuse, Intravenous / epidemiology*
  • Substance-Related Disorders / epidemiology
  • Urban Population

Substances

  • Amphetamines
  • Sodium Hypochlorite
  • Cocaine