Hepatitis C is a hidden epidemic affecting 170 million people worldwide. Hepatitis C kills nearly 700 Australians every year, mostly from chronic liver failure and liver cancer, and costs over $78.9 million in diagnosis and treatment.
Around 230,000 Australians have chronic hepatitis C infection and 6,600 to 13,200 new infections occur every year.
It’s a blood-borne virus, so people who inject drugs have a high prevalence of the infection and the greatest risk of transmission. Although uncommon it can also be transmitted through blood-to-blood contact during sex, sharing razor blades, or using unsterile medical or tattooing equipment.
In Australia the two main hepatitis C genotypes are genotype 1 and 3, occurring in about 55% and 35%-40% of people of people infected with hepatitis C respectively. However genotype is not known to significantly impact on the severity of illness.
Hepatitis C can be treated with a combination of drugs called pegylated interferon and ribavirin – self-administered weekly injections for 24 to 48 weeks and twice-daily capsules. The current treatment comes with a number of unpleasant and serious side effects such as nausea, fever, depression and the risk of birth defects if users become pregnant. Worst of all, the cure rate is less than 75%.
Consequently, few Australians undergo treatment (less than 3,000 people in 2012) and the idea that hepatitis C could be eradicated has long seemed a distant possibility.
But recent advances in hepatitis C treatment give reason for optimism.
New therapies
New hepatitis C treatments known as direct-acting antiviral (DAA) therapies are likely to require only six to 12 weeks of treatment, have minimal side effects and cure rates of over 90%, including in people with advanced liver disease or who have previously failed therapy.
The United States Food and Drug Administration and the European Medicines Agency have already approved sofosbuvir, a highly effective DAA, to treat people with hepatitis C genotypes 2 and 3.
The manufacturer is seeking similar approval in Australia through the Therapeutic Goods Administration and listing on the Pharmaceutical Benefits Scheme, which would make it available for $36.90 or $6 for concession card holders. The Australian government would pay the remaining cost.
Although sofosbuvir is still being used in combination with pegylated interferon to treat hepatitis C genotype 1 (the most common subtype), pegylated-free regimes should be available in the next 12 months. Patients will then only need to take a tablet once or twice a day.
Treatment as prevention
Thanks to DAAs, treatment as prevention, a concept more commonly associated with HIV, is gaining credence in the hepatitis C field. Put simply, if someone with hepatitis C is treated and cured, the individual benefits by avoiding chronic liver disease and the broader community benefits because the patient can no longer transmit the virus to another person.
Modelling undertaken both internationally and within Australia suggests that a treatment-as-prevention approach using DAAs, combined with effective harm reduction strategies – such as needle and syringe and methadone programs – could markedly reduce hepatitis C prevalence over the next 15 years and eventually eliminate the virus.
While it will be vital that people with advanced liver disease have early access to DAAs, the success of treatment-as-prevention hinges on the treatment of people who currently transmit the hepatitis C virus, regardless of the severity of their disease.
Current modelling suggests that in Melbourne, the number of people infected with hepatitis C would halve if we treated 40 per 1,000 people who inject drugs over the next 15 years.
This will mean treating 500 to 1,000 people per year, which might not seem many but will pose a considerable economic challenge for government; the likely cost of a course of non-interferon DAA treatment is $80,000–$100,000.
Despite the cost of this initial investment – over $50 million per year – there are enormous long-term benefits to the individual, as well as being highly cost effective for the community.
Overcoming the barriers
A key issue for the treatment-as-prevention approach is engaging effectively with the group at most risk of hepatitis C. There is no guarantee that people who inject drugs will be willing to engage in early therapy; many have more immediate health and social problems.
In addition, many people who inject drugs have encountered stigma and discrimination in past dealings with health services and health professionals, and might reasonably be sceptical of a treatment-as-prevention approach that appears to primarily benefit others.
It will be important to locate treatment services in easily accessible community locations, and staff them with people experienced in working with drug users who can attend to their complex health needs.
Another concern is that the health resources needed for treatment could be diverted from successful prevention and harm reduction programs, notably needle and syringe programs and opiate substitution therapy. These programs have successfully reduced the risk of transmission of hepatitis C and other blood-borne viruses such as HIV, as well as reducing other injecting-related harms.
Eliminating hepatitis C is an ambitious but achievable goal; the new DAAs will kickstart this process, but it needs a strategic approach, in partnership with people who have or are at risk of hepatitis C infection. We need a sustained and multi-pronged approach – and the time to start is now.