Controlling HIV in Indigenous Australians

Until now, the prevalence of HIV in the Indigenous community has been considered similar to that in the non-Indigenous community.1 In this issue of the Journal (page 124), Wright et al present evidence of a higher rate of HIV among Indigenous people in Western Australia than in the non-Indigenous population.2 They report that, while the rate of HIV notifications in the non-Indigenous population declined between 1985 and 2002, it increased in the Indigenous population. The difference in risk for Indigenous women was striking — 39% of all female HIV notifications in WA since 1994 have been for Indigenous women, giving an Indigenous : non-Indigenous age-standardised rate ratio of 18. In contrast, the rate ratio for Indigenous males was 2. Wright et al also confirmed the marked differentials in risk of other sexually transmitted infections (STIs) in the Indigenous population — with Indigenous : non-Indigenous age-standardised rate ratios of 242 for syphilis, 77 for gonorrhoea and 16 for chlamydia. The data in this study are likely to predominantly reflect the situation in rural and remote regions of WA, and the authors acknowledge the difficulties of interpreting surveillance data. Nevertheless, the findings demand attention.

Health-seeking behaviour based on the presence of genital symptoms or awareness of risk is limited in many Indigenous communities: the concept of “sexual health” is a construct usually confined to well-resourced urban populations. Few Indigenous children in remote areas complete high school and, as a result, there are few reliable means of informing young people about health risks. Although many Aboriginal Health Services have instituted local programs of distribution, condom use appears to be uncommon,3 and there is anecdotal evidence of an increase in injection drug use in remote areas. In settings of social disruption and dislocation, such as among individuals who congregate on the fringes of major urban areas, sex is often exchanged for favours, alcohol and other substances. Not surprisingly, reinforcement and maintenance of health messages and wide implementation of interventions are difficult to achieve in these settings.

It is not entirely clear why the prevalence of HIV has remained low in remote Aboriginal Australia; however, this might be explained by the structure of local sexual networks. In simple terms, the sexual network identifies who is having sex with whom, how often and where. Individuals in a sexual network operate in a social space, not necessarily a geographic space. Because of the sensitivity surrounding this issue, there has been very little published on the complex sociocultural factors that determine the structure of Indigenous sexual networks in remote Australia. It is known that Indigenous people living in remote areas may travel extensively across the country, but are likely to choose partners they already know and who share the same background. This has been termed “assortative” partnering, and has been observed in other populations.4

The absence of HIV from a network protects all its members — it is only when an HIV-infected individual enters the network that transmission occurs. Such individuals may have travelled to large urban areas and contracted HIV through injection drug use or homosexual contact. As a result, a substantial proportion of the members of the sexual network will become infected, although in small communities the absolute numbers will remain low. This implies that control of HIV in the Indigenous population will require multiple small interventions that target individual sexual networks, as well as reflecting the local sociocultural conditions.

In the 1990s, the rates of curable STIs (chlamydia, gonorrhoea and trichomoniasis) were found to be many times higher in the Indigenous population in the Northern Territory, compared with the non-Indigenous population. However, the rate of a non-curable, viral STI (human papillomavirus) was higher in the non-Indigenous than in the Indigenous population. This suggested that a major reason for the disparity in rates is the limited access to and use of clinical services in remote areas, rather than differences in average rates of partner change.5

Health professionals who have worked in remote health settings know how hard it is to do more than simply react to the patients who walk through the clinic doors with an acute problem. Maintaining population health programs, such as immunisation, health promotion and risk factor modification, is always difficult in these settings, and these programs are first to suffer when a medical crisis occurs.

The opportunity costs of a local HIV epidemic are considerable: HIV does not just affect the individual who is infected — sexual partners are also at risk, and transmission can occur antenatally and during breastfeeding. Ongoing risk behaviour after a diagnosis of HIV is documented, driven by psychiatric and substance abuse-related factors. The medical system is compelled to react to the presence of HIV infection in a particular community. In one remote community, this required an increase in the staff of the local public health unit from three to eight, and other programs fell by the wayside (unpublished data). This migration of resources may be one of the major costs of an HIV epidemic in remote Indigenous Australia.

Evidence from Africa suggests that STI control early in an HIV epidemic may be effective in limiting the spread of HIV,6 but this strategy is less useful once the HIV epidemic is established. Good STI control requires a coordinated program that addresses health promotion, diagnostic and screening services, rapid access to appropriate treatment and locally appropriate contact tracing. This is not easy, nor cheap, but it is possible — as seen with a successful program in Central Australia.7 Others have also implemented relatively effective programs.8 Primary care providers can use a new Medicare rebate item (item 710) to screen for STIs in Indigenous people as part of a broader preventive health assessment. The new National Aboriginal and Torres Strait Islander Sexual Health and Blood Borne Virus Strategy, to be announced later in the year, will provide a useful review of existing programs, and recommendations for specific action.

HIV testing is central to HIV control: it determines the extent of the epidemic and helps plan local interventions. Antenatal screening and antiviral treatment of an HIV-infected mother can almost eliminate the risk of transmission of HIV to the neonate; appropriately timed therapy has obvious benefits for the individual in terms of morbidity and mortality, and successful treatment reduces the viral load and decreases the risk of transmitting HIV through sexual contact. There is no need to reinvent guidelines for testing in Indigenous settings — they already exist. Sustainable implementation is the challenge that faces primary care providers. The data from Wright et al provide a compelling reason for meeting this challenge now.