Hepatitis C Background
Hepatitis C Background
Hepatitis C is the new global epidemic liver disease, affecting 200 million people. It is the cause for half of the 10,000 adult liver transplants performed every year and 30% of deaths from liver cancer. An estimated 40,000 New Zealanders have a life-long hepatitis C infection, with an additional 25 infected every week.
The Hepatitis C virus is transmitted when infected blood comes into direct contact with another person’s bloodstream. Contaminated blood and blood-products caused the virus to spread prior to 1992. However, since the introduction of screening for the virus, there have been no recognised cases reported.
The most common way of contracting Hepatitis C in New Zealand and throughout the world is through blood-to-blood contact with infected intravenous drug users. The majority of the estimated 19, 000 injecting drug users in New Zealand have Hepatitis C infection, including both opiate and methamphetamine users.
Despite considerable research, there is still no effective vaccine which can protect against the Hepatitis C infection. This is because the Hepatitis C virus mutates continuously and is able to avoid any protective immune responses produced by the vaccine. After exposure to the Hepatitis C virus through either contaminated blood or injecting equipment, approximately 20% of people with Hepatitis C will be able to clear the virus completely. In most, this acute infection will only produce a mild illness which is often asymptomatic.
The remaining 80%+ are unable to eradicate the virus and therefore develop a life-long (chronic) Hepatitis C infection. The effects of chronic Hepatitis C may be either within the liver (hepatic effects) or outside the liver (extra hepatic effects).
Hepatic Effects: every one with chronic HCV infection will have low grade inflammation (hepatitis), which may cause scarring (fibrosis). Liver damage in chronic Hepatitis C progresses very slowly. After 30 years of infection, about 10% will develop severe scarring (cirrhosis). Once cirrhosis has developed, then there is a small risk of developing life-threatening complications of liver failure and liver cancer (combined risk of 5% per year after cirrhosis has developed, but nil risk in the absence of cirrhosis).
Extra Hepatic Effects: These are common and non-specific effects of the body’s immune system reacting to the HCV virus in the bloodstream. They include skin rashes, thyroid problems, tiredness and mood disorders. Previously, these symptoms have been dismissed as unrelated, but there is now clear evidence that these symptoms will disappear following successful eradication of HCV through antiviral therapy.
The effectiveness of antiviral treatment has improved dramatically over the last decade. Cure rates, which were less than 10% in the early 1990s, now exceed 60% (and 80% in some strains). However, the current antiviral agents (pegylated interferon and ribavirin) are associated with side-effects which may be severer and debilitating during the usual 48 weeks of therapy.
The best way to reduce the impact of Hepatitis C on our community is through public education of the risk factors associated with HCV infection, namely injecting drug use. Increased public awareness will encourage voluntary screening of those with a previous risk of HCV exposure, enabling earlier diagnosis and treatment. It will also encourage the reduction of high-risk behaviour, through avoidance of injecting drug use and promoting needle exchange programs in current users, thereby preventing initial infection and subsequent transmission.
Hepatitis C Fact Sheet
Worldwide, 200 million people currently
infected with HCV
In New Zealand, 40, 000 currently infected with HCV
Another 25 New Zealanders are infected every week, 1300 each year
Cost of HCV-related liver disease on the NZ health system over the next 30 years will be $400 million
Almost two thirds of current injecting drug users have HCV and 1/3 of all injecting drug users under 25 years old
Hepatitis C is 10x more infectious then HIV, but less infectious than
- Hepatitis C is the leading cause for
liver transplantation in adults
- New antiviral therapies will cure most cases of Hepatitis C
- Risk factors for Hepatitis C transmission in New Zealand are:
or previous injected drug use - – even if only once!
2. time in prison – rate of infection is 10-20 times higher
3. body piercing or tattoo’s performed in unsterile conditions
4. transfused blood and blood products prior to 1992
5. shared razor, toothbrush with infected person
- Risk of sexual transmission of HCV is
- Risk of transmission during pregnancy from mum to baby is 5%