Nick Crofts

Spread of bloodborne viruses among Australian prison entrants

Abstract Objectives: To assess spread of bloodborne viruses among prison entrants in Victoria, Australia. Design: Voluntary confidential testing of all prison entrants for markers of exposure to bloodborne viruses with collection of minimal data on demography and risk factors over 12 months. Setting: Her Majestys Prisons, Pentridge and Fairlea, Victoria, Australia. Subjects: 3429 male and 198 female prison entrants (>99% of all prison entrants); 344 entered prison and were tested more than once. Main outcome measures: Prevalence and incidence of antibodies to HIV, hepatitis B, and hepatitis C viruses, and minimal data on risk factors. Results: 1562 (46%) gave a history of use of injected drugs, 1171 (33%) had antibody to hepatitis B core antigen, 1418 (39%) were anti-hepatitis C positive including 914 (64%) of the men who injected drugs, 91 (2.5%) were positive for hepatitis B surface antigen, and 17 (0.47%) were positive for antibody to HIV. Incidence rates for infection with hepa Conclusions: Hepatitis B and C are spreading rapidly through some populations of injecting drug users in Victoria, particularly among men aged less than 30 years at risk of imprisonment in whom rates of spread are extreme; this group constitutes a sizeable at risk population for spread of HIV. This spread is occurring in a context of integrated harm reduction measures outside prisons for prevention of viral spread but few programmes within or on transition from prisons; it poses an urgent challenge to these programmes. Key messages Key messages These programmes are seen to be effective in controlling the spread of HIV among injecting drug users among whom prevalence of HIV remains low There is, however, continued spread at high rates of hepatitis C and B among young injecting drug users entering prisons in Australia The highest rates (41% a year for hepatitis C and 21% a year for hepatitis B) are occurring among young male injecting drug users There is an urgent need to refocus harm reduction programmes to cope with the challenge of hepatitis C and to ensure prisoners are at no greater risk inside or on transition from prisons than they are outside

The prevalence and the risk behaviours associated with the transmission of hepatitis C virus in Australian correctional facilities

This study measured the prevalence and the risk factors associated with HCV antibody-positive prisoners. A total of 630 prisoners completed a questionnaire about risk behaviours associated with HCV transmission and were tested for HCV antibody from a blood test. Of these 362 (57.5%) prisoners were HCV antibody positive. A total of 436 (68.8%) prisoners reported ever injecting drugs and 332 reported injecting drugs in prison. HCV-positive prisoners were more likely to have injected drugs (OR 29.9) and to have injected drugs in prison during their current incarceration (OR 3.0). Tattooing was an independent risk factor for being HCV positive (OR 2.7). This is the first study conducted on prisoners that has identified having a tattoo in prison as a risk factor for HCV. Injecting drugs whilst in prison during this incarceration was also a risk factor for HCV. Our results show prisoners who injected drugs outside of prison continue to inject in prison but in a less safe manner.

Blood-borne virus infections among Australian injecting drug users: Implications for spread of HIV

To describe the epidemiology of infection with hepatitis C virus (HCV), hepatitis B virus (HBV) and human immunodeficiency virus (HIV) among injecting drug users (IDUs) in Australia, in relation to the potential for further spread of HIV in IDUs, a cross-sectional analysis was performed on data from a sample of injecting drug users, correlating markers of exposure to blood-borne viruses with sex, age, sexual orientation, primary current drug injected and duration of injecting in rural and metropolitan Victoria, Australia. The subjects were currently active IDUs from a wide spectrum of age, sex, sexual orientation, geographical location and social background, contacted and recruited through their social networks and from community agencies and prisons by trained peer workers who interviewed and collected blood from them in the field. Sera were tested for antibody to HIV, HCV and hepatitis B core antigen (HBcAg), for hepatitis B surface antigen (HBsAg), and for HCV RNA using reverse transcription and polymerase chain reaction (RT-PCR). At entry to the study, 4.5% (14/311) had antibody to HIV, 47% (146/308) to HBcAg and 68% (206/303) to HCV. Prevalence of HBsAg was 1.8% overall (5/282), and 50% (84/168) were positive for HCV RNA. By multivariate analysis, HIV seropositivity was strongly associated with a history of homosexual contact in males and with exposure to HBV but not to HCV. Those who reported their current primary injected drug to be amphetamines were at greater and continuing risk of HIV infection than were current heroin injectors, while the reverse applied for HCV. The different patterns of exposure to different blood-borne viruses in this particular population of IDUs probably reflects different interactions among different social networks. HCV exposure provides a good surrogate marker for risk behaviour among these IDUs, but HBV exposure provides a better marker for risk of HIV infection. More detailed surveillance strategies for HIV infection, and more targeted HIV prevention programs are necessary to detect and to prevent further spread of HIV in these populations.

Detection of multiple hepatitis C virus genotypes in a cohort of injecting drug users

Summary.  Multiple genotypes of the hepatitis C virus (HCV) were detected in five of 138 HCV RNA positive injecting drug users (IDUs) recruited in Melbourne, Australia. Two were detected by combined LiPA and core and NS5a region sequencing, and three more (selected for testing due to their high‐risk behaviour) by heteroduplex mobility analysis. We conclude that the true prevalence of mixed infection in IDUs is undoubtedly higher than the 3.6% (five of 138) we observed, and is underestimated by LiPA, the most common method of genotyping. As responsiveness to HCV treatment varies significantly with genotype, a high prevalence of mixed HCV infections in IDUs must diminish overall treatment efficacy and lessen our ability to reduce the burden of HCV‐related disease.

Vulnerability among Vietnamese illicit drug users in Australia: challenges for change

A broad range of vulnerabilities, risk factors and challenges for change were examined in order to better understand why ethnic Vietnamese have the highest profile in Australia in relation to illicit drug use. A literature review of vulnerability and risk factors experienced by ethnic Vietnamese people in Australia was conducted. Emerging themes and concepts were tested against the 1996 Australian Census (Victoria), databases specific to illicit drug use, and the outcomes of key informant interviews and community consultations. Vietnam-born Australians are the third largest ethnic community in Australia. Due to high unemployment, poor English proficiency, experiences of racism, social and economic difficulties, inter-generational conflicts and acculturation, the ethnic Vietnamese community has become vulnerable to involvement with illicit drug use and distribution. Addressing drug problems among the ethnic Vietnamese community in Australia is hampered by a lack of structured, appropriate education and employment programs, biased media reporting and poor utilisation of drug treatment services. Socio-economic disadvantage and level of exclusion from the legitimate economy heighten involvement in illicit drug use and its associated harms.

A computer model of the spread of hepatitis C virus among injecting drug users

A number of behavioural and clinical parameters influence the transmission of an infectious agent through direct contact between two individuals. The behavioural parameters encountered in such situations are also likely to exhibit an enormous amount of variability. With the spread of hepatitis C among injecting drug users, the parameters associated with injecting behaviour play an important role in the modelling of the transmission process. Computer simulation modelling is an ideal approach to deal with a large number of parameters as well as high levels of variability without excessive simplification. The simulation model presented in this paper is tested on data from a cohort of injecting drug users and the results obtained are very encouraging from a public health perspective. The model clearly indicates that the rate at which HCV spreads through a population of injecting drug users is extremely sensitive to the interaction rate and to the probability of infection through a single contact with an infective. At the same time it shows that rate of spread is not very sensitive to initial prevalence, which is very encouraging from a public health perspective.

The pattern of notification and testing for genital Chlamydia trachomatis infection in Victoria, 1998-2000: an ecological analysis

Objective:This ecological study analyses routinely collected chlamydia notification and testing data to investigate any patterns.

Exposure to hepatitis A virus among blood donors, injecting drug users and prison entrants in Victoria.

Summary. To assess prevalence of exposure to hepatitis A virus (HAV) among injecting drug users (IDUs) and prison entrants in Victoria, and to compare this with prevalence of HAV among a reference population of blood donors, sera stored from two previous studies and from randomly selected blood donors were tested for total antibody to HAV. The first study was a longitudinal study of field‐recruited EDUs from 1990 to 1992 and the second was a study of all prison entrants in 1991‐92 (both studies were carried out in Victoria); blood donors were from the Australian Red Cross Blood Bank Victoria in 1995. Forty five per cent of 2175 prison entrants and 51% of 293 IDUs were seropositive for HAV, compared with 30% of 2995 blood donors. When standardized for age against the blood donors, HAV seropositivity in IDUs was 44% and in prison entrants 60%. The strongest association of HAV seropositivity among the EDUs on multivariate analysis was a history of imprisonment. There are high rates of exposure to HAV among prison entrants, whether with a history of EDU or not, and among IDUs who have a prison history. The role of sharing contaminated injecting equipment in transmission of HAV seems to be less important than institutionalization per se. With adequate resourcing, both populations are appropriate targets for HAV vaccination, especially in a context of continuing decline of transmission of HAV in the general community.

HIV, ethnicity and travel: HIV infection in Vietnamese Australians associated with injecting drug use

BACKGROUND The movement of people with their constructed identities including ethnicity has always been one of the determinants of the human immunodeficiency virus (HIV) pandemic. An example of the contributions of travel and ethnicity to experiences of HIV can be seen in the Vietnamese community in Australia. OBJECTIVES This paper seeks to describe the contributions of ethnicity and travel to the Australian HIV epidemic with particular reference to the evolving epidemic within the Vietnamese Australian community. STUDY DESIGN We reviewed the available data on the HIV epidemic in Australia with reference to overseas acquisition, ethnicity, the epidemic in the Vietnamese community and the determinants of the current patterns of transmission within this community. RESULTS Available data suggests that 20-25% of HIV infections notified in Australia are acquired overseas. This proportion is higher in some specific categories such as heterosexually acquired infections. Notification rates are no higher in Vietnamese Australians than in the general Australian population apart from infections associated with injecting drug use (IDU) notified in the state of Victoria. The reasons for this increased rate of notification include increased vulnerability to blood borne virus infection in Australia and the additional, unique risk of frequent travel to Vietnam, a country where IDU carries a high risk of HIV infection. CONCLUSIONS Australia has succeeded in stabilising the HIV epidemic partly through successful interventions to limit the spread of infection among IDUs. There is now early evidence that HIV transmission may be increasing amongst Vietnamese Australian IDUs. Timely responses that help Vietnamese Australian IDUs reduce their accumulation of risk are likely to be important in determining the level of harm associated with IDU throughout Australia.

Indications of Immune Protection from Hepatitis C Infection

Hepatitis C affects many millions of people worldwide and is at very high prevalence among people who inject drugs. In our study of hepatitis C virus (HCV) in the social networks of injecting drug users (IDUs), five IDUs with injecting careers of 9 years or more were HCV antibody and RNA negative. All injected frequently with HCV RNA-positive IDUs, and two had recently injected with the syringe of an RNA-positive IDU. Our data suggest the existence of immune protection from HCV infection.