Name: Hepatitis C virus (HCV).
Synonym or Cross Reference: HCV Footnote 1-13, non-A non-B hepatitis Footnote 3, Footnote 12, Footnote 14, parenterally transmitted non-A non-B hepatitis, non-B transfusion-associated hepatitis, post-transfusion non-A non-B hepatitis Footnote 2, and HCV infection Footnote 1-4, Footnote 6, Footnote 7, Footnote 10, Footnote 11.
Characteristics: HCV belongs to the Flaviviridae family Footnote 3, Footnote 5 and Hepacavirus genus, and is a small (50nm), single-stranded, enveloped RNA virus Footnote 2, Footnote 3. HCV was originally characterised in 1989 Footnote 14, and has 6 major genotypes and over 100 subtypes Footnote 5. The main genotypes of HCV in North America are types 1, 2, and 3 Footnote 1.
Pathogenicity/Toxicity: Acute HCV infection: Asymptomatic in most patients (60-75%) Footnote 1, Footnote 3, Footnote 5. The syndrome of acute hepatitis is often preceded or accompanied by symptoms of fatigue, myalgia, low-grade fever Footnote 1, Footnote 3, right upper quadrant pain, nausea, vomiting Footnote 3, jaundice, mild hepatosplenomegaly, maculopapular rash, and arthralgia Footnote 1. These symptoms may last for 2 to 12 weeks Footnote 1.
Chronic HCV infection: While a minority of those infected will spontaneously clear an acute infection with HCV, in most cases (50-85%), the infection will become chronic Footnote 1. Some patients with chronic HCV infection experience: malaise, nausea, abdominal pain and pruritis. Fluctuating alanine transferase levels are characteristic. The late sequelae of chronic HCV infection include serious health consequences such as chronic hepatitis, cirrhosis, and hepatocellular carcinoma Footnote 5. If cirrhosis develops, patients may experience jaundice, splenomegaly, ascites, oesophageal varices, and hepatic encephalopathy. Extrahepatic manifestations are uncommon but may include mixed essential cryoglobulinaemia, membranous or membranoproliferative glomerulonephritis, non-Hodgkin’s lymphoma, Sjorgren’s syndrome, lichen planus, and porphyria cutanea tarda.
Epidemiology: HCV infection is seen worldwide Footnote 2, with the World Health Organization (WHO) estimating a prevalence of 2.2% to 3% Footnote 2-5, or approximately 170 million people Footnote 5. The WHO African region and WHO Eastern Mediterranean region have the highest prevalence of HCV infection Footnote 4.
Infectious Dose: Unknown.
Mode of Transmission: In North America HCV is mainly transmitted parenterally by infected needles, particularly those used by intravenous drug users Footnote 1, Footnote 3, Footnote 12. Other parenteral routes exist such as blood transfusion, organ transplantation, contaminated medical equipment, and from tattoo and body piercing equipment Footnote 3. However, for the last decade or so the risk of HCV infection through blood transfusion in Canada, and North America as well, is negligible Footnote 16. Less common routes of HCV transmission are via sexual contact, from sharing razors and/or toothbrushes, and from mother to child during pregnancy and childbirth.
Communicability: Can be transmitted from person-to-person. Transmission rate between mother and developing child is influenced by maternal levels of viraemia (greater than 106 copies per ml blood), and also co-infection of the mother with HIV Footnote 2, Footnote 3, Footnote 5.
Drug Susceptibility: Sensitive to interferon-α (IFN), pegylated interferon, and ribavirin Footnote 1. New antiviral treatments that work by targeting hepatitis C protease and polymerase are currently in clinical trials Footnote 17.
Drug Resistance: Resistance has been observed to be emerging against IFN and the current methods of therapy Footnote 18, and the outcome of treatment is highly dependent on viral genotype Footnote 19.
Susceptibility to Disinfectants: HCV RNA is readily degraded by 2% glutaraldehyde when added to biological samples at 37°C Footnote 6, and soaking medical equipment (such as gastroendoscopes) in 3% glutaraldehyde is effective at limiting HCV transmission Footnote 7. Phenolic compounds (0.4 to 3%) are effective at inhibiting HCV binding and infectivity in VERO cell cultures Footnote 8. Furthermore, treatment of HCV diluted in phosphate buffered saline with 1% non-ionic detergent (Triton X-100) plus 0.3% tri-n-butyl-phosphate leads to inactivation Footnote 13.
Physical Inactivation: HCV is inactivated when incubated at 60°C for 10 hours (pasteurisation) Footnote 13.
Survival Outside Host: HCV is relatively unstable; however, in plasma it can survive drying and environmental exposure to room temperature for at least 16 hours Footnote 9.
Surveillance: Monitor for symptoms. The initial test for HCV infection is an enzyme immunoassay for HCV antibodies Footnote 1, Footnote 2, Footnote 12. PCR Footnote 1-3, Footnote 12, Footnote 13 methods are also used to detect HCV RNA. Other tests include the branched DNA assay and transcription mediated amplification Footnote 2, Footnote 3.
Note: All diagnostic methods are not necessarily available in all countries.
First Aid/Treatment: Treatment success rates with antiviral therapy have improved significantly over the last 10 years Footnote 1. Mono-therapy with pegylated interferon (addition of polyethylene glycol to interferon-α) and combined therapy of pegylated interferon with ribavirin, or standard interferon with ribavirin, are common methods of treating HCV infection Footnote 1, Footnote 10.
Immunization: None Footnote 1, Footnote 8, Footnote 11; however, several vaccines that prevent initial infection or viral persistence, or that clear viraemia in individuals with chronic HCV infections, are in development Footnote 10, Footnote 20.
Prophylaxis: Postexposure prophylaxis with immune globulin or antiviral agents is not recommended Footnote 11.
Laboratory-Acquired Infections: Unknown, although seroprevalence studies have reported antibody to HCV rates of 1% among hospital based (including laboratory workers and healthcare providers) in Western countries Footnote 12.
Sources/Specimens: Blood Footnote 1, Footnote 3, Footnote 9, Footnote 12, Footnote 13, blood products Footnote 1, Footnote 3, Footnote 12, and bodily fluids, tissues, or equipment contaminated with HCV infected blood Footnote 1, Footnote 7, Footnote 9.
Special Hazards: None.
Risk Group Classification: Risk Group 2Footnote 21.
Containment Requirements: Containment Level 2 facilities, equipment, and operational practices for work involving infectious or potentially infectious materials, animals, or cultures.
Protective Clothing: Lab coat. Gloves when direct skin contact with infected materials or animals is unavoidable. Eye protection must be used where there is a known or potential risk of exposure to splashes Footnote 22.
Other Precautions: All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC). The use of needles, syringes, and other sharp objects should be strictly limited. Additional precautions should be considered with work involving animals or large scale activities Footnote 22.
Spills: Allow aerosols to settle and, wearing protective clothing, gently cover spill with paper towels and apply an appropriate disinfectant, starting at the perimeter and working towards the centre. Allow sufficient contact time before clean up.
Disposal: Decontaminate all materials for disposal by steam sterilisation, chemical disinfection, and/or incineration.
Storage: In sealed containers that are appropriately labelled.
Regulatory Information: The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.
Updated: November 2010.
Prepared by: Pathogen Regulation Directorate, Public Health Agency of Canada.
Although the information, opinions and recommendations contained in this Pathogen Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.
Public Health Agency of Canada, 2010