Hepatitis C Virus

Introduction

Hepatitis C virus (HCV) is a flavivirus that that mostly produces chronic infections. Most patients are asymptomatic and are only identified when they develop chronic liver disease.

Mechanism of spread

HBV is spread through blood and body fluids. Most cases are due to infected blood in IV drug use.

Clinical features

8% of those exposed to HCV become chronically infected. It is usually asymptomatic until severe chronic hepatitis or cirrhosis develops. Non-specific symptoms include fatigue, nausea, anorexia and weight loss. It may be discovered incidentally during a routine blood test, which can show raised ALT.

Acute symptomatic infection is rare.

Investigations

Blood tests are all that are required to confirm the diagnosis. These primarily look at:

• LFTs: raised bilirubin and ALT when liver damage develops.
• Viral serology: HCV RNA confirms ongoing infection and used for monitoring response to treatment
• Antibodies: Anti-HCV antibodies appear 6-12 weeks following acute infection
• Molecular analysis of HCV: confirms genotype (genotypes 1-6) to guide treatment

Liver biopsy is often required to stage liver damage as ALT is a poor indicator in HCV.

Management

The aim is to eradicate the infection.

Drug therapy

New medications have been introduced for treating HCV in recent years. These viral protein inhibitors include simeprevir, ledipasvir and sofosbuvir. They have been shown to be highly efficacious and are mainly used for treating HCV genotypes 1 or 4.  More than 95% of patients are able to achieve clinically undetectable HCV RNA after >12 weeks of treatment with these new drugs.

Previous mainstream therapy included dual therapy with pegylated interferon and ribavirin. While they are not as effective as the above new drugs, they can be used to treat the more resistant HCV genotypes 2 and 3.

Liver transplant

Transplantation should be considered in cases of decompensated cirrhosis. However, it should be noted that HCV almost always recurs in transplants. Up to 15% of patients develop cirrhosis within 5 years of transplant.

Complications

• Cirrhosis
• Hepatocellular carcinoma
• Cryoglobulinemia
• Sjögren’s syndrome

Prevention

No active or passive immunisation is currently available.