The Australian National AIDS and Injecting Drug Use Study was designed
to monitor the risk behaviour of Australian injecting drug users (IDU
s) in a number of major cities, and to estimate the seroprevalence of
those interviewed. Differences in risk behaviour found across 2 years
in Perth are reported. One hundred and ninety-six Perth IDUs were inte
rviewed in 1989, and 150 in 1990 using the same survey questionnaire,
with a small cohort of 38 respondents being followed up across the 2 y
ears. Significant injecting differences between 1989 and 1990 in both
the cohort and independent samples were found. In general, these amoun
ted to a greater likelihood that a new needle and syringe would be use
d on each injecting occasion, and a greater use of bleach in 1990 than
in 1989. The most common response of respondents who said they had ch
anged their drug use behaviour in 1990 was to report ceasing to share
needles, while the most common response in 1989 was reduced sharing, T
here was an increased use of condoms for vaginal intercourse with all
partners in both studies across the 2 years. Seropositivity for all ne
w cases across the 2 years was 1.75%. It is apparent that there has be
en a significant shift in risky behaviour in the direction of greater
safety across the 2 years. There is also objective corroborative evide
nce in increased demand for sterile injecting equipment sold through p
harmacists, although there is no evidence that drug use increased sign
ificantly during the same period. It is concluded that the availabilit
y of sterile needles and syringes should be maintained and improved an
d that emphasis should be placed on encouraging safer sexual behaviour
among IDUs.