Hepatitis C is likely to become a significant public health problem in the UK in the next decade. It is thought around 200,000 people are chronically infected with the virus. At risk groups include intravenous drug users and patients who received a blood transfusion prior to 1991 (e.g. haemophiliacs).

Pathophysiology

• hepatitis C is a RNA flavivirus
• incubation period: 6-9 weeks

Transmission

• the risk of transmission during a needle stick injury is about 2%
• the vertical transmission rate from mother to child is about 6%. The risk is higher if there is coexistent HIV
• breastfeeding is not contraindicated in mothers with hepatitis C
• the risk of transmitting the virus during sexual intercourse is probably less than 5%
• there is no vaccine for hepatitis C

After exposure to the hepatitis C virus only around 30% of patients will develop features such as:

• a transient rise in serum aminotransferases / jaundice
• fatigue
• arthralgia

Investigations

• HCV RNA is the investigation of choice to diagnose acute infection
• whilst patients will eventually develop anti-HCV antibodies it should be remembered that patients who spontaneously clear the virus will continue to have anti-HCV antibodies

Outcome

• around 15-45% of patients will clear the virus after an acute infection (depending on their age and underlying health) and hence the majority (55-85%) will develop chronic hepatitis C

Chronic hepatitis C

Chronic hepatitis C may be defined as the persistence of HCV RNA in the blood for 6 months.

Potential complications of chronic hepatitis C

• rheumatological problems: arthralgia, arthritis
• eye problems: Sjogren's syndrome
• cirrhosis (5-20% of those with chronic disease)
• hepatocellular cancer
• cryoglobulinaemia: typically type II (mixed monoclonal and polyclonal)
• porphyria cutanea tarda (PCT): it is increasingly recognised that PCT may develop in patients with hepatitis C, especially if there are other factors such as alcohol abuse
• membranoproliferative glomerulonephritis

Management of chronic infection

• treatment depends on the viral genotype - this should be tested prior to treatment
• the management of hepatitis C has advanced rapidly in recent years resulting in clearance rates of around 95%. Interferon based treatments are no longer recommended
• the aim of treatment is sustained virological response (SVR), defined as undetectable serum HCV RNA six months after the end of therapy
• currently a combination of protease inhibitors (e.g. daclatasvir + sofosbuvir or sofosbuvir + simeprevir) with or without ribavirin are used