hepatitis C

hepatitis C
Name	hepatitis C
Specialty	Hepatology, Infectious disease
Symptoms	Jaundice, fatigue, abdominal pain, arthralgia
Complications	Cirrhosis, hepatocellular carcinoma, liver failure
Onset	Acute or chronic
Duration	Acute (weeks) or chronic (years to decades)
Causes	Hepacivirus infection
Risks	Injection drug use, transfusion before screening, healthcare exposure
Diagnosis	Anti-HCV antibodies, HCV RNA PCR, liver biopsy, elastography
Prevention	Blood screening, syringe programs, infection control
Treatment	Direct-acting antivirals, interferon (historical)

hepatitis C Hepatitis C is a bloodborne viral infection of the liver caused by a single-stranded RNA virus in the genus Hepacivirus. It commonly produces chronic liver disease that may progress to cirrhosis and hepatocellular carcinoma over decades; effective antiviral therapies have transformed prognosis. Management intersects with public health initiatives, transplantation programs, and harm-reduction efforts.

Introduction

Hepatitis C virus (HCV) infection was historically recognized after transfusion-associated non-A, non-B hepatitis events that led investigators at institutions such as Centers for Disease Control and Prevention, National Institutes of Health, and World Health Organization to seek etiologic agents. Landmark contributions from laboratories at Chiron Corporation and investigators like Michael Houghton culminated in molecular identification and assay development. Subsequent global surveillance programs by World Health Organization and national agencies reshaped blood safety and antiviral research agendas at centers like Mayo Clinic and Johns Hopkins Hospital.

Virology and Pathophysiology

HCV is an enveloped, positive-sense single-stranded RNA virus within the family Flaviviridae; its replication machinery and error-prone polymerase generate diverse quasispecies, complicating immune clearance and vaccine development. Viral proteins such as core, E1, E2, NS3, NS4A, NS5A, and NS5B mediate entry, replication, and assembly; NS5B encodes the RNA-dependent RNA polymerase targeted by nucleoside analogues. Hepatocyte tropism leads to immune-mediated hepatocellular injury involving cytotoxic T lymphocytes and cytokine responses characterized in studies at Karolinska Institute and Institut Pasteur. Chronic inflammation promotes fibrogenesis via hepatic stellate cell activation described in work from University of California, San Francisco and University College London.

Transmission and Risk Factors

Primary routes of transmission include percutaneous exposures and parenteral procedures. Injection drug use with shared syringes is the dominant mode in many countries; outbreak investigations have involved public health teams from Public Health England and Centers for Disease Control and Prevention. Before nucleic acid screening implemented by entities such as American Red Cross and national blood services, transfusion and organ transplantation were major risks. Occupational exposures in healthcare settings prompted policy changes at World Health Organization and Occupational Safety and Health Administration. Less common routes include vertical transmission during childbirth, reported in cohort studies at University of Liverpool and Imperial College London; sexual transmission is inefficient but documented in cohort research at Fenway Health and cohorts of people living with HIV at San Francisco General Hospital.

Clinical Presentation and Diagnosis

Acute infection is frequently asymptomatic or presents with fatigue, jaundice, anorexia, and elevated transaminases; symptomatic descriptions appear in clinical reviews from Cleveland Clinic and Massachusetts General Hospital. Chronic infection is often silent until advanced fibrosis or hepatocellular carcinoma develops; surveillance algorithms echo guidance from European Association for the Study of the Liver and American Association for the Study of Liver Diseases. Diagnostic testing includes serologic detection of anti-HCV antibodies and confirmation by HCV RNA PCR assays developed by diagnostics firms and laboratories at Abbott Laboratories and Roche Diagnostics. Genotyping (1–7) informs historical treatment choice; transient elastography and liver biopsy from centers like Mount Sinai Hospital assess fibrosis stage.

Prevention and Screening

Blood and organ donor screening implemented worldwide by blood services such as National Health Service Blood and Transplant and regulatory agencies markedly reduced transmission. Harm-reduction strategies include syringe services programs and opioid substitution therapy advocated by World Health Organization and community organizations like Harm Reduction International. Infection control practices in hospitals follow guidelines from Centers for Disease Control and Prevention and World Health Organization. Screening recommendations target birth cohorts, people who inject drugs, and incarcerated populations per policy statements from United States Preventive Services Task Force and European Centre for Disease Prevention and Control.

Treatment and Management

Therapeutic advances center on direct-acting antivirals (DAAs) targeting NS3/4A protease, NS5A, and NS5B polymerase, transforming cure rates to >95% in many settings; pivotal trials involved collaborations among academic centers, pharmaceutical companies like Gilead Sciences and AbbVie, and regulatory review by Food and Drug Administration. Prior interferon-based regimens developed at institutions such as Vanderbilt University Medical Center had lower efficacy and greater toxicity. Management of advanced liver disease includes variceal surveillance, hepatocellular carcinoma screening per Barcelona Clinic Liver Cancer guidelines, and transplantation coordination with programs at Cleveland Clinic and UCLA Medical Center. Reinfection prevention relies on public health measures and education by organizations like World Hepatitis Alliance.

Epidemiology and Public Health Impact

Global prevalence estimates by World Health Organization indicate tens of millions of people with chronic infection; burden is heterogenous with high prevalence reported in studies from Egypt, Pakistan, and parts of Eastern Europe. The disease contributes substantially to liver-related morbidity and mortality reported in analyses from Global Burden of Disease Study and national vital statistics systems such as Centers for Disease Control and Prevention. Elimination goals adopted by World Health Organization and national programs in countries like Australia and Portugal emphasize diagnosis, treatment scale-up, and prevention to reduce incidence and mortality.

Category:Liver disease