UCSF study identifies sexual exposure as a major means of HIV transmission among injection drug user

By Jeff Sheehy

HIV infection among injection drug users (IDUs) in San Francisco is strongly
associated with sexual behavior, with men who have sex with men (MSM) and women
who trade sex for money much more likely to become infected than other IDUs,
according to a study by UCSF researchers.

The study published in the May 5, 2001 issue of The Lancet, looked at data
collected about IDUs in San Francisco from 1986 through 1998. Researchers found
that over this time period, MSMs were 8.8 times more likely and women who
reported trading sex for money were 5.1 times more likely than other IDUs in
San Francisco to become infected with the HIV virus.

“We have had success here in San Francisco with keeping the incidence of HIV
among IDUs low by reducing needle-related risks for HIV with programs like drug
treatment and needle exchange. This study establishes that sexual behaviors
also pose a significant risk to IDUs for transmission of HIV,” said the study’s
lead author, Alex Kral, PhD, assistant adjunct professor at UCSF’s Urban Health
Study which is part of the Institute for Health Policy Studies and Department
of Family and Community Medicine. .

“There has been a tendency for IDU prevention programming to be needle
obsessed, and here in San Francisco that has worked to a certain degree. Now,
we need to focus new energy on sexual risk reduction among IDUs, while
continuing current programs that address needle-borne risks,” added Kral.

The data for the study was collected from 1,192 participants of the Urban
Health Study, a study of street-recruited IDUs conducted in San Francisco from
1986 through 1998.  The UCSF Urban Health Study was the first and is the
longest running study of IDUs recruited from the streets and not from drug
treatment centers.

Study co-investigators are Ricky N. Bluthenthal, PhD, associate sociologist
with the Health Program and Drug Policy Research Center at Rand and assistant
professor at Charles R. Drew University of Medicine and Science; Jennifer
Lorvick, staff research associate, Lauren Gee, MPH, senior statistician, and
Brian R. Edlin, MD, associate adjunct Professor and director, all of them at
UCSF’s Urban Health Study; and Peter Bacchetti, PhD, adjunct professor in UCSF’
s Department of Epidemiology and Biostatistics.

The research was supported by grants from the National Institute on Drug Abuse,
the University of California’s Universitywide AIDS Research Program and the San
Francisco Department of Public Health.