Hepatitis C: waiting for the Grim Reaper

The incidence and prevalence of hepatitis C in Australia are far higher than those of HIV infection. An estimated 130 000 Australians have been infected with hepatitis C virus (HCV) over the last 20 years, with about 6000 new chronic infections a year through injecting drug use alone.¹ In contrast, an estimated 15 450 people have been infected with HIV by all routes of transmission, with about 500 new infections a year between 1994 and 1996.² Although a smaller proportion of individuals infected with HCV experience serious morbidity and mortality, and only after a longer delay (10%-20% are estimated -- conservatively -- to develop cirrhosis within 20 years and 5% of these develop hepato cellular carcinoma within five years),³ the far larger pool of infected people and longer duration of illness suggest that the total health and economic burden of hepatitis C in Australia is considerable and may well surpass HIV before too long.

The task of bringing hepatitis C under control is daunting. While the pieces of the hepatitis C jigsaw puzzle are still being assembled, injecting drug use is undeniably the major mode of transmission in Australia and other developed countries.

In this issue of the Journal, Sladden and colleagues found that 85% of hepatitis C notifications involved IDUs. Their epidemiological study analysed notifications of hepatitis C from a community sample and assigned risk factors for a high proportion of respondents. However, the high non-response rate of 53% and the statistically significant differences between respondents and non-respondents qualify their findings. In contrast to Sladden and colleagues' results, a United States study estimated a much lower proportion of IDUs among hepatitis C notifications, but could not assign risk factors for as high a proportion of respondents.⁴ As official policy in the US advocates "zero tolerance" for any illicit drug use, it is hardly surprising that many American IDUs were apparently intimidated from revealing their risk behaviour.

Could a harm reduction/public health approach control hepatitis C among IDUs? Such an approach, which includes needle exchange and methadone treatment programs, has already been successful in stabilising the HIV epidemic among IDUs in Australia. In contrast, the US "War on Drugs", which has resulted from the official policy of "zero tolerance" for any illicit drug use, has had catastrophic public health consequences. In 1994, IDUs accounted for only 2.5% of AIDs cases in Australia,⁸ compared with 28% in the US in 1993.⁹ While the prevalence of AIDS (per million population) in the United States was 4.3 times that in Australia in 1988, by 1992 this ratio had increased to 6.4,¹⁰ fuelled by an uncontrolled epidemic among IDUs and a secondary epidemic among heterosexual contacts of HIV-positive IDUs in the US.

Despite the success of the harm reduction/public health approach in controlling the HIV epidemic and slowing the spread of hepatitis B among IDUs in Australia, it appears not to have reduced the incidence of hepatitis C.¹ There is a very real possibility that hepatitis C transmission among IDUs requires only minimal breaches of infection control guidelines.¹ Hepatitis C virus is an order of magnitude more infective than HIV,¹¹ and hepatitis C has a far higher baseline prevalence than HIV infection. Consequently, while expanding needle exchange and methadone treatment programs may reduce hepatitis C incidence, this is unlikely to control the epidemic.

The approach of eliminating importation or global production of injectable drugs continues to enjoy some support, especially during long election campaigns, but it is increasingly apparent that this is an expensive fantasy. Even a major architect of Nixon's "War on Drugs", the former White House adviser John Erlichman, testified to a US Senate Subcommittee: "the people in the federal government . . . know darn well that the massive war they have mounted on narcotics is only going to be effective at the margins. If they don't know it, they ought to know it."¹² Reducing drug supply or demand is seemingly a more realistic objective, but the evidence of past decades provides little grounds for optimism.

While attempts to eliminate harm from illicit drugs almost universally fail, efforts to reduce harm generally succeed. Therefore, encouraging drug users to adopt non-injecting routes of administration (sniffing, smoking, snorting or swallowing) appears to offer our best hope for achieving hepatitis C control among IDUs. Smoking of heroin has overtaken injecting in popularity in many parts of the United States, the United Kingdom and the Netherlands.¹³ Reasons differ between these countries but are thought to include, in the US, the scarcity of sterile injecting equipment, coupled with drug users' fear of contracting HIV infection through needle sharing, and (most importantly) the recent drop in price and increase in purity of available heroin. In other countries, the increased availability of heroin base, which has a lower melting point than heroin hydrochloride and is thus more suitable for smoking, has played a part. A strategy of promoting non-injecting routes of administration also offers the hope of reducing the growing epidemic of drug overdoses, which claim about 500 young Australian lives each year.

We are beginning to recognise hepatitis C as a public health problem comparable in magnitude with HIV. The recent inclusion of hepatitis C in the Third National HIV/AIDS Strategy means that it will at least be included in a national policymaking apparatus, which delivered splendid, internationally recognised results for HIV/AIDS. Only when there is a national commitment to raise levels of awareness about the seriousness of this epidemic will Australia stand a chance of controlling hepatitis C. Until Australia embarks on a major national awareness-raising exercise, such as a "Grim Reaper"-style public education campaign, the band will continue to play on for hepatitis C as it once did for HIV.

Alex Wodak
Director, Alcohol and Drug Service,
St Vincent's Hospital, Sydney, NSW.

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