First identified in 1989, at least six genotypes (subtypes) have been identified worldwide, but genotype 1 and 3 are commonest in Ireland.
How can one become infected with Hepatitis C?
Routine blood testing was unavailable in Ireland before 1991. Since then however, the mode of transmission has been shown to be primarily parenteral (blood to blood), formerly by blood products, and recently by intravenous drug use, with needle sharing.
The risks of infection by sexual and mother to baby transmission are thought to account for less than 1% and 5% respectively. There have been reports of HCV infection in men who have sex with men recently, many of whom are HIV positive. HCV infection in the drug-using community is widespread, with as many as 70% of intravenous drug-users believed to be infected.
What are the signs and symptoms of Hepatitis C?
Chronic HCV infection is often silent, frequently discovered only at routine blood testing, and is believed to occur in at least 70% of patients infected, 30% are believed to clear the virus without treatment. Most people infected do not have symptoms in early disease.
How is Hepatitis C diagnosed?
Diagnosis of HCV infection depends on a high level of suspicion, coupled with the detection of antibodies to HCV.
A diagnosis of chronic hepatitis C can be made by detecting the HCV virus genetic material in the blood (HCV-RNA). HCV-RNA positive patients may be referred for liver biopsy to determine the extent of liver damage. Treatment is offered to those with chronic active disease (persistent viraemia). HCV infection is self-limiting in a percentage of infected individuals.
The prognosis in chronic infection varies greatly, but it would appear that 30% of patients ultimately develop cirrhosis and disability from end stage liver disease within 30 years. Factors affecting prognosis include age at time of infection, cross addiction with alcohol, co-existing HIV and/or HBV infection and genotype.
How is Hepatitis C treated?
Currently, dual therapy with pegylated interferon alpha and ribavirin appears to be the most clinically relevant disease modifying agents available.
The pegylated interferon is administered subcutaneously (under the skin) once a week and ribavirin is taken orally twice a day. Treatment is genotype dependent, 24 weeks for genotype 3 and 48 weeks for genotype 1. A sustained viral response is documented by a negative HCV-RNA six months after treatment completion. The response rate to treatment with genotype 3 is as high as 80%, approximately twice as effective as with genotype 1. There are new HCV drugs coming on line in the coming months which will improve treatment outcomes for many.
Is there any aftercare required following Hepatitis C Infection?
Persons infected with hepatitis C who clear the virus following treatment will be followed up routinely to guarantee sustained viral clearance.
How is Hepatitis C prevented?
Sexual spread of hepatitis C is decreased by consistent and correct condom usage.