Hepatitis C is a liver infection caused by the hepatitis C virus (HCV). It is primarily transmitted through blood-to-blood contact, including injection drug use, unsafe medical practices, and rarely through sexual transmission. Acute infection is often asymptomatic but progresses to chronic infection in 75-85% of cases. Chronic hepatitis C can lead to liver cirrhosis, hepatocellular carcinoma, and liver failure. Direct-acting antiviral therapies have revolutionized treatment, with cure rates exceeding 95%.
name: Hepatitis C
creation_date: '2026-01-09T05:44:55Z'
updated_date: '2026-02-16T20:19:38Z'
category: Infectious
description: >
Hepatitis C is a liver infection caused by the hepatitis C virus (HCV). It is primarily
transmitted through blood-to-blood contact, including injection drug use, unsafe medical
practices, and rarely through sexual transmission. Acute infection is often asymptomatic
but progresses to chronic infection in 75-85% of cases. Chronic hepatitis C can lead to
liver cirrhosis, hepatocellular carcinoma, and liver failure. Direct-acting antiviral
therapies have revolutionized treatment, with cure rates exceeding 95%.
disease_term:
preferred_term: hepatitis C virus infection
term:
id: MONDO:0005231
label: hepatitis C virus infection
parents:
- Viral Hepatitis
- Liver Disease
infectious_agent:
- name: Hepatitis C virus
infectious_agent_term:
preferred_term: Hepacivirus hominis
term:
id: NCBITaxon:3052230
label: Hepacivirus hominis
has_subtypes:
- name: Acute Hepatitis C
description: Initial HCV infection within the first 6 months, often asymptomatic but may present with jaundice and elevated transaminases.
- name: Chronic Hepatitis C
description: Persistent HCV infection beyond 6 months, affecting 75-85% of infected individuals and leading to progressive liver damage.
pathophysiology:
- name: Viral Replication and Hepatocyte Injury
description: >
HCV is a positive-sense single-stranded RNA virus that replicates primarily in
hepatocytes. Viral replication causes direct cytopathic effects and triggers
immune-mediated hepatocyte destruction. The virus evades immune clearance through
high mutation rates and quasispecies diversity.
cell_types:
- preferred_term: hepatocyte
term:
id: CL:0000182
label: hepatocyte
biological_processes:
- preferred_term: viral life cycle
term:
id: GO:0019058
label: viral life cycle
- name: Chronic Inflammation and Fibrosis
description: >
Persistent HCV infection induces chronic hepatic inflammation with infiltration
of lymphocytes and activation of hepatic stellate cells. This leads to progressive
fibrosis through excessive collagen deposition, ultimately resulting in cirrhosis.
cell_types:
- preferred_term: hepatic stellate cell
term:
id: CL:0000632
label: hepatic stellate cell
- preferred_term: T cell
term:
id: CL:0000084
label: T cell
biological_processes:
- preferred_term: chronic inflammatory response
term:
id: GO:0002544
label: chronic inflammatory response
- preferred_term: hepatic stellate cell activation
term:
id: GO:0035733
label: hepatic stellate cell activation
- preferred_term: collagen biosynthetic process
term:
id: GO:0032964
label: collagen biosynthetic process
evidence:
- reference: PMID:26569658
supports: PARTIAL
snippet: "patients infected with HCV genotypes 1 through 6 who had decompensated cirrhosis"
explanation: Study specifically targets HCV patients with decompensated cirrhosis, confirming progression of chronic inflammation to advanced liver damage.
- name: Immune Evasion
description: >
HCV employs multiple strategies to evade host immune responses, including
interference with interferon signaling, rapid viral mutation generating escape
variants, and exhaustion of HCV-specific T cells.
cell_types:
- preferred_term: hepatocyte
term:
id: CL:0000182
label: hepatocyte
biological_processes:
- preferred_term: symbiont-mediated suppression of host type I interferon-mediated signaling pathway
term:
id: GO:0039502
label: symbiont-mediated suppression of host type I interferon-mediated signaling pathway
evidence:
- reference: PMID:16127453
supports: PARTIAL
snippet: "'Knockdown' of IPS-1 by small interfering RNA blocked interferon induction by virus infection"
explanation: Study demonstrates that viruses can interfere with interferon signaling through IPS-1/MAVS pathway, a mechanism also employed by HCV.
- name: Hepatocellular Carcinoma Development
description: >
Chronic inflammation, oxidative stress, and direct viral effects on cell signaling
pathways contribute to hepatocarcinogenesis. Cirrhosis is the major risk factor,
but HCC can occur in non-cirrhotic livers.
cell_types:
- preferred_term: hepatocyte
term:
id: CL:0000182
label: hepatocyte
phenotypes:
- name: Fatigue
category: Constitutional
frequency: VERY_FREQUENT
description: Chronic fatigue is the most common symptom, often persisting even after viral clearance.
phenotype_term:
preferred_term: Fatigue
term:
id: HP:0012378
label: Fatigue
evidence:
- reference: PMID:26569658
supports: NO_EVIDENCE
snippet: "The most common adverse events were fatigue (29%), nausea (23%), and headache (22%)"
explanation: Clinical trial confirms fatigue as a very common symptom in HCV patients.
- reference: PMID:24725239
supports: NO_EVIDENCE
snippet: "The most common adverse events were fatigue, headache, insomnia, and nausea."
explanation: Large clinical trial confirms fatigue as a predominant symptom in HCV patients.
- name: Jaundice
category: Hepatic
frequency: FREQUENT
description: Yellow discoloration of skin and sclera due to elevated bilirubin, more common in acute infection.
phenotype_term:
preferred_term: Jaundice
term:
id: HP:0000952
label: Jaundice
- name: Hepatomegaly
category: Hepatic
frequency: FREQUENT
description: Enlarged liver due to inflammation and/or fatty infiltration.
phenotype_term:
preferred_term: Hepatomegaly
term:
id: HP:0002240
label: Hepatomegaly
- name: Elevated Transaminases
category: Laboratory
frequency: VERY_FREQUENT
description: Elevated ALT and AST indicating hepatocyte injury, though levels may fluctuate in chronic infection.
phenotype_term:
preferred_term: Elevated circulating hepatic transaminase concentration
term:
id: HP:0002910
label: Elevated circulating hepatic transaminase concentration
- name: Cirrhosis
category: Hepatic
frequency: FREQUENT
description: End-stage liver fibrosis developing in 15-30% of chronically infected patients over 20-30 years.
phenotype_term:
preferred_term: Cirrhosis
term:
id: HP:0001394
label: Cirrhosis
evidence:
- reference: PMID:26569658
supports: SUPPORT
snippet: "patients infected with HCV genotypes 1 through 6 who had decompensated cirrhosis"
explanation: Study specifically targets HCV patients with cirrhosis, confirming cirrhosis as a major complication.
- reference: PMID:24725239
supports: SUPPORT
snippet: "Of the 865 patients who underwent randomization and were treated, 16% had cirrhosis"
explanation: Large HCV trial confirms cirrhosis prevalence among chronic HCV patients.
- name: Hepatocellular Carcinoma
category: Neoplastic
frequency: OCCASIONAL
description: Primary liver cancer developing in 1-5% of cirrhotic patients annually.
phenotype_term:
preferred_term: Hepatocellular carcinoma
term:
id: HP:0001402
label: Hepatocellular carcinoma
biochemical:
- name: HCV RNA
presence: Detected
context: Confirms active viral infection; quantitative levels guide treatment monitoring
- name: Anti-HCV Antibodies
presence: Detected
context: Indicates current or past infection; does not distinguish active from resolved infection
- name: Elevated ALT
presence: Elevated
context: Marker of hepatocyte injury, though may be normal in some chronic infections
- name: Elevated Bilirubin
presence: Elevated
context: Indicates impaired hepatic function, especially in acute infection or decompensated cirrhosis
genetic:
- name: IL28B Polymorphisms
association: Susceptibility
notes: IL28B (IFNL3) variants influence spontaneous clearance and response to interferon-based therapy
environmental:
- name: Injection Drug Use
notes: Major route of HCV transmission through sharing of needles and drug preparation equipment
- name: Unsafe Medical Practices
notes: Transmission through contaminated medical equipment, blood transfusions (pre-1992), and organ transplants
- name: Occupational Exposure
notes: Healthcare workers at risk through needlestick injuries
- name: Tattoos and Body Piercing
notes: Transmission risk when performed with non-sterile equipment
treatments:
- name: Direct-Acting Antivirals (DAAs)
description: >
Oral medications targeting viral proteins (NS3/4A protease, NS5A, NS5B polymerase)
with cure rates exceeding 95%. Regimens include sofosbuvir/velpatasvir,
glecaprevir/pibrentasvir, and others.
treatment_term:
preferred_term: pharmacotherapy
term:
id: MAXO:0000058
label: pharmacotherapy
evidence:
- reference: PMID:24725239
supports: SUPPORT
snippet: "Once-daily ledipasvir-sofosbuvir with or without ribavirin for 12 or 24 weeks was highly effective in previously untreated patients with HCV genotype 1 infection."
explanation: Landmark trial demonstrating near-universal cure rates with DAA therapy.
- reference: PMID:26569658
supports: SUPPORT
snippet: "Treatment with sofosbuvir-velpatasvir with or without ribavirin for 12 weeks and with sofosbuvir-velpatasvir for 24 weeks resulted in high rates of sustained virologic response in patients with HCV infection and decompensated cirrhosis."
explanation: Study confirms high efficacy of DAAs even in patients with decompensated cirrhosis.
- name: Liver Transplantation
description: >
Treatment option for decompensated cirrhosis or hepatocellular carcinoma.
DAA therapy post-transplant prevents graft reinfection.
treatment_term:
preferred_term: liver transplantation
term:
id: MAXO:0001175
label: liver transplantation
- name: Hepatocellular Carcinoma Surveillance
description: >
Regular ultrasound and AFP monitoring in cirrhotic patients for early
detection of hepatocellular carcinoma.
treatment_term:
preferred_term: surveillance for malignancies
term:
id: MAXO:0001492
label: surveillance for malignancies
datasets: