Incidence of bloodborne virus infection and risk behaviours in a cohort of injecting drug users in Victoria, 1990‐1995

Abstract

ObjectiveTo assess changes in risk behaviours for transmission of bloodborne viruses and incidences and prevalences of these viruses in a field‐recruited cohort of injecting drug users. DesignProspective longitudinal cohort study. SettingMetropolitan and rural Victoria, June 1990 to December 1995. Subjects626 current injecting drug users (i.e., who had injected drugs within the previous 12 months). Main outcome measuresSeroconversion to HIV and hepatitis B and C viruses (HBV and HCV); risk behaviours for infection. ResultsHIV incidence was very low (0.2 per 100 person‐years). HCV incidence was high (10.7 per 100 person‐years), but fell throughout the study, although the downward trend did not reach statistical significance. HBV incidence was moderate (1.8 per 100 person‐years) and did not fall. Prevalence of risk behaviours, notably sharing needles and syringes, decreased significantly. ConclusionsSignificant change has occurred in the risk behaviours of the cohort, confirming results of cross‐sectional studies of injecting drug use. This change may be responsible for the apparent decline in HIV and HCV incidence. Further studies are needed to monitor the incidence of bloodborne viruses in injecting drug users. Efforts to decrease risk of transmission should continue.

Prevalence and incidence of hepatitis B virus infection in STD clinic attendees in Pune, India

“…This estimated incidence of HBV is higher than that reported in injecting drug users in Switzerland (2.1% per 100 person years), 14 and in Australia (1.8 per 100 person years). 15 HBV incidence observed in our study population was also higher than that reported in men having sex with men (MSM) in Brazil (4.44 per 100 person years). 16 Among the sexual behaviour variables, "anal sex in males with commercial sex workers" only was found to be associated with incident HBV infection.…”

Infection with HIV and hepatitis C virus among injecting drug users in a prevention setting: retrospective cohort study

“…A recently published prospective cohort study among injecting drug users in another Australian state revealed a decline in incidence of hepatitis C virus, albeit non-significant, of 16.6 to 8.1/100 person years over the period 1990-5 31. The absence of a similar decline in this study among an inner city population of injecting drug users already attending an HIV prevention service strongly suggests that current efforts aimed at the prevention of bloodborne viral transmission are inadequate to stem hepatitis C virus infection.…”

Screening injecting drug users for sexually transmitted infections and blood borne viruses using street outreach and self collected sampling

“…The time from assault to presentation ranged from three to 72 hours and six patients presented later than 24 hours. They received the PEP an average of 58 minutes after presentation, one with zidovudine alone and the rest with three drugs including either zidovudine and lamivudine (12) or stavudine and lamivudine (1) with either nelfinavir (9) or indinavir (4). Thirteen patients accepted prophylaxis against chlamydia and gonorrhoea and 12 took emergency contraception.…”

“…12 13 In contrast with North America and eastern Europe, where an HIV prevalence of 5-56% in IDUs has been reported, 3 14 15 the HIV prevalence in Australian IDUs is significantly lower at 1-2%. 12 16 Injecting drug use is associated with unsafe sexual practices and a high prevalence of STIs. [1][2][3] Factors contributing to a high risk of STIs include exchange of sex for drugs, high rates of commercial sex work, high lifetime number of sexual partners and partner change, and high lifetime prevalence of STIs.…”