Credit: http://www.gicare.com/ pated/ecdlv42.htm	Credit: http://path.upmc.edu/cases/ case17/micro.html	Credit: http://www.prn.org/images/ prn_nb_cntnt_images/models/hcv_model_q1.jpg

History:

• Idenified in 1989 in chimpanzees
• Was a major cause of post-transfusion hepatitis before routine screening of blood supply

Epidemiology

• More than 170 million carriers in the world
• 4 million are infected in the US
• Virus causes chronic disease with shedding during asymptomatic periods
• No seasonal incidence
• Worldwide prevalence
• High prevalence areas:
  • southern Italy
  • Spain
  • central Europe
  • Japan
  • Egypt

Structure and Replication

• The virus cannot be grown in culture
• 30-60 nm in diamter
• Genome is 9kb
• Genome encodes 10 proteins, including 2 glycoproteins, E1 and E2
• Infects only humans and chimpanzees
• CD81 receptor
• Uptake into hepatocytes
• Replicates in the cytoplasm and remains in the ER
• Viral proteins inhibit apoptosis and interferon-alpha action by binding to
  TNFR and protein kinase R, preventing cell induced death to maintain chronic infection

Transmission

• Mainly parenteral and sexual
• Highest risk groups:
  • IV drug users
  • Transfusion and organ recipients
  • Hemophiliacs receiving factors VIII or IX
  • HIV+ IV drug users

Clinical Manifestations

• Acute hepatitis lasting 4-6 months with resolution and recovery from infection (15% of cases)
• Chronic infection for more than 10 years that may lead to disease later in life (70% of cases)
• Infection followed by severe and rapid progression of cirrhosis (15% of cases)
• Over 80% of cases are initially asymptomatic and chronic infections
  • 20% of chronic cases progress to chronic active hepatitis and cirrhosis within 10-15 years
  • 20% of cirrhotic cases progress to liver failure after 20 years
• Co-factor
  • Alcohol and HCV cirrhosis
• Oncogenic potential:
  • 5% of chronic infections lead to hepatocellular carcinoma after 30 years

Diagnosis

• ELISA antibody testing for immunocompetent
• Seroconversion within 7-31 weeks of initial infection
• Testing for immunocompromised and hemodialysis recipients:
  • Reverse transcriptase-PCR
  • branched-chain DNA

Treatment

• Recombinant interferon-alpha
• Recombinant interferon-alpha and ribavirin

SOURCE for information (non-image) on this page:

Murray et al. (2002) Medical Microbiology. 4th edition. St. Louis: Mosby. Pages 601-603

Interferon and Hep C Credit: http://www.aerztlichepraxis.de/ aktuell/artikel/1029939107/allgemeinmedizin/leber	Liver cirrhosis Credit: www.brown.edu/.../HepatitisC/ epidmain.html	Chronic HCV liver disease cells Credit: www.brown.edu/.../HepatitisC/ epidmain.html