Hepatitis C
A viral liver infection often becoming chronic, treatable with antivirals.
Hepatitis C is an infectious disease caused by the hepatitis C virus (HCV), which mainly targets the liver and is one of the five known hepatitis viruses (A, B, C, D, and E). The virus was first suspected in the 1970s as a form of non-A, non-B hepatitis, and was confirmed in 1989. It only infects humans and chimpanzees.
In the early stage of infection, most people have either no symptoms or very mild ones. When acute symptoms do appear—typically 4 to 12 weeks after exposure, though it can take anywhere from 2 weeks to 6 months—they may include fever, fatigue, nausea, vomiting, muscle or joint pain, abdominal pain, decreased appetite, weight loss, dark urine, clay-colored stools, and jaundice (which occurs in about 25% of those infected). Acute liver failure from hepatitis C is extremely rare. About 10–50% of those infected clear the virus on their own during this phase, especially younger people and females.
In about 70% of cases, the virus persists in the liver and becomes a chronic infection, defined as detectable viral replication for at least six months. Early on, chronic infection usually causes no symptoms, though some people experience fatigue or mild cognitive issues. Over many years, it often leads to liver disease and, in some cases, cirrhosis. Liver enzymes are normal in 7–53% of those with chronic infection. Fatty changes to the liver occur in about half of those infected, usually before cirrhosis develops. Worldwide, hepatitis C accounts for 27% of cirrhosis cases and 25% of hepatocellular carcinoma (liver cancer). About 10–30% of those with chronic infection develop cirrhosis over 30 years. The risk of cirrhosis is higher in people who also have hepatitis B, schistosoma, or HIV, in heavy drinkers (alcohol increases the risk fivefold), and in males. Those with cirrhosis have a 20-fold greater risk of liver cancer, which develops at a rate of 1–3% per year. Cirrhosis can lead to portal hypertension, ascites (fluid buildup in the abdomen), easy bruising or bleeding, varices (enlarged veins in the stomach and esophagus), jaundice, and hepatic encephalopathy (cognitive impairment). Ascites occurs at some point in more than half of those with chronic infection. Late relapses after apparent cure have been reported, though these can be hard to distinguish from reinfection.
Hepatitis C also causes problems outside the liver.
Quick Facts
- Field
- Gastroenterology, infectious disease
- Symptoms
- Typically none
- Complications
- Liver failure, liver cancer, esophageal and gastric varices
- Duration
- Long term (80%)
- Causes
- Hepatitis C virus usually spread by blood-to-blood contact
- Diagnosis
- Blood testing for antibodies or viral RNA
- Prevention
- Sterile needles, testing donated blood
- Treatment
- Medications, liver transplant
- Medication
- Antivirals (sofosbuvir, simeprevir, others)
- Frequency
- 58 million (2019)
- Deaths
- 290,000 (2019)
Facts from the source article.
Lore & Background
Hepatitis C is caused by the hepatitis C virus (HCV), a small, enveloped, single-stranded, positive-sense RNA virus. During the initial infection period, people often have mild or no symptoms; early symptoms can include fever, dark urine, abdominal pain, and jaundice. The virus persists in the liver, becoming chronic, in about 70% of those initially infected. Over many years, chronic infection often leads to liver disease and occasionally cirrhosis, which can lead to liver failure, liver cancer, or dilated blood vessels in the esophagus and stomach.
Reader's Guide
Hepatitis C is a major global health concern, with an estimated 58 million people infected worldwide in 2019 and approximately 290,000 deaths that year, mainly from liver cancer and cirrhosis. The virus is spread primarily by blood-to-blood contact, such as through injection drug use, poorly sterilized medical equipment, needlestick injuries, and transfusions. In regions where blood screening has been implemented, the risk from transfusions has dropped to less than one per two million. There is no vaccine, but chronic infection can be cured more than 95% of the time with antiviral medications like sofosbuvir or simeprevir. Earlier treatments such as peginterferon and ribavirin were successful in less than 50% of cases and caused greater side effects. By 2022, prices of newer treatments had dropped dramatically in many low-income and lower-middle-income countries due to generic versions. Hepatitis C is one of the leading reasons for liver transplantation, though the virus usually recurs after transplantation.
Did You Know?
- Hepatitis C was originally identifiable only as a type of non-A, non-B hepatitis, suggested in the 1970s and proven in 1989.
- The virus infects only humans and chimpanzees.
- In the United States, screening for HCV infection is recommended in all adults age 18 to 79 years old.
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