Hepatitis C is an infectious disease affecting primarily the liver, caused by the hepatitis C virus (HCV). The infection is often asymptomatic, but chronic infection can lead to scarring of the liver and ultimately to cirrhosis, which is generally apparent after many years. In some cases, those with cirrhosis will go on to develop liver failure, liver cancer or life-threatening esophageal and gastric varices.

Signs and symptoms

Acute infection

Hepatitis C infection causes acute symptoms in 15% of cases.Symptoms are generally mild and vague, including a decreased appetite, fatigue, nausea, muscle or joint pains, and weight loss and rarely does acute liver failure result.Most cases of acute infection are not associated with jaundice.The infection resolves spontaneously in 10-50% of cases, which occurs more frequently in individuals who are young and female.

Chronic infection

About 80% of those exposed to the virus develop a chronic infection. This is defined as the presence of detectable viral replication for at least six months. Most experience minimal or no symptoms during the initial few decades of the infection, although chronic hepatitis C can be associated with fatigue.Chronic infection after several years may cause cirrhosis or liver cancer. The liver enzymes are normal in 7-53%. Late relapses after apparent cure have been reported, but these can be difficult to distinguish from reinfection.

Extrahepatic complications

The most common problem due to hepatitis C but not involving the liver is mixed cryoglobulinemia (usually the type II form) - an inflammation of small and medium-sized blood vessels.Hepatitis C is also associated with Sjögren's syndrome (an autoimmune disorder); thrombocytopenia; lichen planus; porphyria cutanea tarda; necrolytic acral erythema; insulin resistance; diabetes mellitus; diabetic nephropathy; autoimmune thyroiditis and B-cell lymphoproliferative disorders. Thrombocytopenia is estimated to occur in 0.16% to 45.4% of people with chronic hepatitis C. 20-30% of people infected have rheumatoid factor - a type of antibody.Possible associations include Hyde's prurigo nodularis and membranoproliferative glomerulonephritis. Cardiomyopathy with associated arrhythmias has also been reported.A variety of central nervous system disorders have been reported.Chronic infection seems to be associated with an increased risk of pancreatic cancer.

Occult infection

Persons who have been infected with hepatitis C may appear to clear the virus but remain infected.The virus is not detectable with conventional testing but can be found with ultra-sensitive tests. The original method of detection was by demonstrating the viral genome within liver biopsies, but newer methods include an antibody test for the virus' core protein and the detection of the viral genome after first concentrating the viral particles by ultracentrifugation. A form of infection with persistently moderately elevated serum liver enzymes but without antibodies to hepatitis C has also been reported.This form is known as cryptogenic occult infection.

Treatment

HCV induces chronic infection in 50–80% of infected persons. Approximately 40–80% of these clear with treatment. In rare cases, infection can clear without treatment. Those with chronic hepatitis C are advised to avoid alcohol and medications toxic to the liver, and to be vaccinated for hepatitis A and hepatitis B. Ultrasound surveillance for hepatocellular carcinoma is recommended in those with accompanying cirrhosis.