(See also Causes of Hepatitis Causes of Hepatitis Hepatitis is inflammation of the liver characterized by diffuse or patchy necrosis. Hepatitis may be acute or chronic (usually defined as lasting > 6 months). Most cases of acute viral hepatitis... read more , Overview of Acute Hepatitis Overview of Acute Viral Hepatitis Acute viral hepatitis is diffuse liver inflammation caused by specific hepatotropic viruses that have diverse modes of transmission and epidemiologies. A nonspecific viral prodrome is followed... read more , and Chronic Hepatitis C Hepatitis C, Chronic Hepatitis C is a common cause of chronic hepatitis. It is often asymptomatic until manifestations of chronic liver disease occur. Diagnosis is confirmed by finding positive anti-HCV and positive... read more .)
In the US, 4136 cases of acute hepatitis C infection were reported in 2019. However, because many cases are not recognized or not reported, the Centers for Disease Control and Prevention (CDC) estimates that the actual number of new infections was 57,500 in 2019 (1 General reference Hepatitis C is caused by an RNA virus that is often parenterally transmitted. It sometimes causes typical symptoms of viral hepatitis, including anorexia, malaise, and jaundice but may be asymptomatic... read more ). The number of acute hepatitis C cases has been rising in the United States since 2013.
Hepatitis C virus (HCV) is a single-stranded RNA flavivirus that causes acute viral hepatitis Overview of Acute Viral Hepatitis Acute viral hepatitis is diffuse liver inflammation caused by specific hepatotropic viruses that have diverse modes of transmission and epidemiologies. A nonspecific viral prodrome is followed... read more and is a common cause of chronic viral hepatitis Overview of Chronic Hepatitis Chronic hepatitis is hepatitis that lasts > 6 months. Common causes include hepatitis B and C viruses, nonalcoholic steatohepatitis (NASH), alcohol-related liver disease, and autoimmune liver... read more . Six major HCV subtypes exist with varying amino acid sequences (genotypes); these subtypes vary geographically and in virulence and response to therapy. HCV can also alter its amino acid pattern over time in an infected person, producing quasispecies.
HCV infection sometimes occurs simultaneously with specific systemic disorders, including the following:
Porphyria cutanea tarda Porphyria Cutanea Tarda Porphyria cutanea tarda (PCT) is a comparatively common hepatic porphyria affecting mainly the skin. Liver disease is also common. PCT is due to an acquired or inherited deficiency in the activity... read more (about 60 to 80% of porphyria patients have HCV infection, but only a few patients infected with HCV develop porphyria)
The mechanisms are uncertain.
Up to 20% of patients with alcoholic liver disease Alcohol-Related Liver Disease Alcohol consumption is high in most Western countries. According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), 8.5% of US adults are estimated to... read more harbor HCV. The reasons for this high association are unclear because concomitant alcohol and drug use accounts for only a portion of cases. In these patients, HCV and alcohol act synergistically to worsen liver inflammation and fibrosis.
Transmission of hepatitis C
Infection is most commonly transmitted through blood, primarily when parenteral drug users share needles, but also through sharing vessels for intranasal drug use, or tattoos or body piercing with nonsterile equipment.
Sexual transmission and vertical transmission of hepatitis C from mother to infant are relatively rare.
Transmission of hepatitis C through blood transfusion has become very rare since the advent of screening tests for donated blood.
Some sporadic cases occur in patients without apparent risk factors.
HCV prevalence varies with geography and other risk factors.
1. Centers for Disease Control and Prevention (CDC): Hepatitis C questions and answers for health professionals. Accessed June 8, 2022.
Symptoms and Signs of Acute Hepatitis C
Hepatitis C may be asymptomatic during the acute infection. Its severity often fluctuates, sometimes with recrudescent hepatitis and roller-coaster aminotransferase levels for many years or even decades. Fulminant hepatitis Fulminant Hepatitis Fulminant hepatitis is a rare syndrome of rapid (usually within days or weeks), massive necrosis of liver parenchyma and a decrease in liver size (acute yellow atrophy); it usually occurs after... read more is extremely rare.
HCV has the highest rate of chronicity (about 75%). The resultant chronic hepatitis C Hepatitis C, Chronic Hepatitis C is a common cause of chronic hepatitis. It is often asymptomatic until manifestations of chronic liver disease occur. Diagnosis is confirmed by finding positive anti-HCV and positive... read more is usually asymptomatic or benign but progresses to cirrhosis Cirrhosis Cirrhosis is a late stage of hepatic fibrosis that has resulted in widespread distortion of normal hepatic architecture. Cirrhosis is characterized by regenerative nodules surrounded by dense... read more in 20 to 30% of patients; cirrhosis often takes decades to appear. Hepatocellular carcinoma Hepatocellular Carcinoma Hepatocellular carcinoma (HCC) usually occurs in patients with cirrhosis and is common in areas where infection with hepatitis B and C viruses is prevalent. Symptoms and signs are usually nonspecific... read more can result from HCV-induced cirrhosis but results only rarely from chronic infection without cirrhosis (unlike in hepatitis B).
Diagnosis of Acute Hepatitis C
HCV RNA measurement
In the initial diagnosis of acute hepatitis Initial diagnosis of acute hepatitis Acute viral hepatitis is diffuse liver inflammation caused by specific hepatotropic viruses that have diverse modes of transmission and epidemiologies. A nonspecific viral prodrome is followed... read more , viral hepatitis should be differentiated from other disorders causing jaundice (see figure Simplified diagnostic approach to possible acute viral hepatitis Simplified diagnostic approach to possible acute viral hepatitis ).
If acute viral hepatitis is suspected, the following tests are done to screen for hepatitis viruses A, B, and C:
IgM antibody to hepatitis A virus (IgM anti-HAV)
Hepatitis B surface antigen (HBsAg)
IgM antibody to hepatitis B core (IgM anti-HBc)
Antibody to HCV (anti-HCV) and HCV RNA
If the anti-HCV test is positive, HCV RNA is measured to distinguish active from past hepatitis C infection (see table Hepatitis C Serology Hepatitis C Serology ).
In hepatitis C, serum anti-HCV represents chronic, past, or acute infection; the antibody is not protective. When cases are unclear or when suspicion for hepatitis C is high, HCV RNA is measured. Anti-HCV usually appears within 2 weeks of acute infection but is sometimes delayed; however, HCV RNA is positive sooner.
Liver tests are needed if not previously done; they include serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase.
Other tests should be done to evaluate liver function and disease severity; they include serum albumin, bilirubin, platelet count, and prothrombin time/international normalized ratio (PT/INR).
Treatment of Acute Hepatitis C
There are a number of highly effective direct-acting antiviral drugs Overview of HCV treatment (DAAs) for hepatitis C that may decrease the likelihood of developing chronic infection. DAAs also help prevent transmission to others. Current recommendations are to start treatment after the initial diagnosis of acute HCV, without waiting for spontaneous resolution.
Alcohol and hepatotoxic drugs (eg, acetaminophen) should be avoided because it can increase liver damage. Restrictions on diet or activity, including commonly prescribed bed rest, have no scientific basis.
Viral hepatitis should be reported to the local or state health department.
1. American Association for the Study of Liver Diseases (AASLD)–Infectious Diseases Society of America (IDSA): HCV Guidance: Recommendations for testing, managing, and treating hepatitis C: Management of acute HCV infection. Accessed June 8, 2022.
Prevention of Acute Hepatitis C
Patients should be advised to avoid high-risk behavior (eg, sharing needles to inject drugs, getting tattoos and body piercings).
Blood and other body fluids (eg, saliva, semen) are considered infectious. Risk of infection after a single needlestick exposure is about 1.8%. Barrier protection is recommended, but isolation of patients is of no value in preventing acute hepatitis C.
Risk of transmission from HCV-infected medical personnel appears to be low, and there are no CDC recommendations to restrict health care workers with hepatitis C infection from working.
Posttransfusion infection is minimized by avoiding unnecessary transfusions and screening all donors for hepatitis B and C. Screening has decreased the incidence of posttransfusion hepatitis B and hepatitis C, which are now extremely rare in the US.
No product exists for immunoprophylaxis of HCV. The propensity of HCV for changing its genome hampers vaccine development.
Preexposure or postexposure prophylaxis with antiviral therapy is not recommended.
Hepatitis C is usually transmitted by parenteral contact with contaminated blood; transmission from mucosal contact with other body fluids and perinatal transmission from infected mothers are rare.
About 75% of patients with acute hepatitis C develop chronic hepatitis C, which leads to cirrhosis in 20 to 30%; some patients with cirrhosis develop hepatocellular carcinoma.
Diagnose by testing for antibody to HCV and HCV RNA.
Treat with antiviral drugs after initial diagnosis of hepatitis C, without waiting for spontaneous resolution.
There is no vaccine for hepatitis C.
The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
Centers for Disease Control and Prevention (CDC): Viral Hepatitis: Hepatitis C questions and answers for health professionals: This resource provides an overview of hepatitis C (including definitions, statistics, risk factors, and complications) and information about transmission, symptoms, diagnosis, and treatment, as well as hepatitis C and pregnancy. Accessed July 6, 2022.