Hepatitis C

Hepatitis C virus is a flavivirus and an RNA virus. It is a common cause of cirrhosis and liver cancer globally. Chronic hepatitis C is the most common cause for liver transplantation. Curative treatment exists. Before the introduction of modern antivirals, curing HCV was much less successful and involved the use of interferons, which have nasty side effects. Thanks to modern antivirals, curing HCV has become much easier.

Etiology

Like hepatitis B and D, transmission is parenteral, sexual, or perinatal. The most common route of transmission is IV drug use.

Clinical features

The incubation time is 4 – 12 weeks. The acute infection is asymptomatic in 80%; jaundice occurs in 20%.

Chronic hepatitis occurs in 70% and is an important cause of cirrhosis and HCC.

Diagnosis and evaluation

Diagnosis can be made based on serology (anti-HCV) or HCV RNA by PCR. Anti-HCV appears 12 weeks after exposure, which is after the symptomatic period, so anti-HCV is used for screening of asymptomatic persons.

To diagnose HCV in symptomatic persons, HCV RNA should be measured instead. If HCV RNA is present in a sufficient amount, the laboratory can determine the virus' genotype.

Most patients are recognized in the chronic stage.

Treatment

In 15-45% of infected people the virus clears without any treatment.

Both acute and chronic hepatitis C can be cured with direct-acting antivirals (DAAs), but people with acute HCV should be monitored for 12 – 16 weeks for whether they clear the infection themselves. If not, treatment is initiated.

Treatment with DAA lasts 8-12 weeks and is successful in 95% of cases. Treatment involves combination of 2 or 3 antivirals like sofosbuvir, velpatasvir, and ledipasvir, usually in one tablet. 4-12 weeks after treatment, a blood test should be made to ensure that the virus has been cleared, by measuring HCV-RNA levels. Some genotypes of HCV are resistant to certain antivirals, knowing the virus' genotype is useful to guide the choice of antiviral.