Hepatitis C virus (HCV) is the most common cause of liver disease, cirrhosis and liver cancer in the USA. HCV is also the most common reason why patients need a liver transplant. The most common reasons why patients acquire HCV is because they utilized illicit injection drugs or inhaled cocaine with a person who was already infected with HCV. Patients may also have received a blood or plasma transfusion prior to 1990 when HCV was first discovered and before donated blood could be tested for this virus. It is extremely rare for HCV to be transmitted through sexual interaction. HCV cannot be transmitted by food or casual interactions with a person with HCV. Approximately 20% of persons with chronic HCV have no obvious source of how they acquired this infection.
Over 80% of persons who are infected with HCV develop chronic disease. This means the virus does not go away. Many, but not all patients with chronic HCV have elevated liver enzymes in their blood. A blood test can detect these elevated liver enzymes and the amount of this virus (HCV RNA) in the blood of a patient. The level of HCV RNA in the blood does not have any relation to the severity of the liver disease caused by chronic HCV. Tha majority of patients with chronic HCV slowly develop damage to the liver and increasing amounts of scaring until cirrhosis has developed. This process takes 20-30 years. Patients with cirrhosis are at increased risk to develop liver failure and liver cancer.
The majority of patients with chronic HCV are asymptomatic. Of those patients with symptoms, the most common is fatigue. Some patients develop aches in the joints or a discoloration in the lower legs. HCV can also cause kidney damage and diabetes.
There are several different types of HCV called genotypes. The most common genotype in the USA is type 1 which affects 65% of persons. Most of the remaining persons in this country have genotypes 2 or 3.