Pathogen Safety Data Sheets: Infectious Substances – Hepatitis C virus

Pathogen Safety Data Sheet - Infectious Substances

Section I - Infectious Agent

Name: Hepatitis C virus (HCV).

Synonym or Cross Reference: HCV Footnote 1-13, non-A non-B hepatitis Footnote 3Footnote 12Footnote 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 1-4Footnote 6Footnote 7Footnote 10Footnote 11.

Characteristics: HCV belongs to the Flaviviridae family Footnote 3Footnote 5 and Hepacavirus genus, and is a small (50nm), single-stranded, enveloped RNA virus Footnote 2Footnote 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.

Section II - Hazard Identification

Pathogenicity/Toxicity: Acute HCV infection: Asymptomatic in most patients (60-75%) Footnote 1Footnote 3Footnote 5. The syndrome of acute hepatitis is often preceded or accompanied by symptoms of fatigue, myalgia, low-grade fever Footnote 1Footnote 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.

Host Range: Humans Footnote 1-5Footnote 7Footnote 10-12Footnote 15. Chimpanzees have been used as experimental hosts Footnote 2Footnote 5Footnote 9Footnote 10Footnote 13.

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 1Footnote 3Footnote 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.

Incubation Period: Ranges from 2 to 12 weeks Footnote 1Footnote 3.

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 2Footnote 3Footnote 5.

Section III - Dissemination

Reservoir: Humans Footnote 2Footnote 3Footnote 5.

Zoonosis: None.

Vextors: None.

Section IV - Stability and Viability

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.

Section V - First Aid / Medical

Surveillance: Monitor for symptoms. The initial test for HCV infection is an enzyme immunoassay for HCV antibodies Footnote 1Footnote 2Footnote 12. PCR Footnote 1-3Footnote 12Footnote 13 methods are also used to detect HCV RNA. Other tests include the branched DNA assay and transcription mediated amplification Footnote 2Footnote 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 1Footnote 10.

Immunization: None Footnote 1Footnote 8Footnote 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 10Footnote 20.

Prophylaxis: Postexposure prophylaxis with immune globulin or antiviral agents is not recommended Footnote 11.

Section VI - Laboratory Hazards

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 1Footnote 3Footnote 9Footnote 12Footnote 13, blood products Footnote 1Footnote 3Footnote 12, and bodily fluids, tissues, or equipment contaminated with HCV infected blood Footnote 1Footnote 7Footnote 9.

Primary Hazards: Needlestick injury Footnote 3Footnote 12, or cuts with sharp instruments Footnote 12.

Special Hazards: None.

Section VII - Exposure Controls / Personal Protection

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.

Section VIII - Handling and Storage

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.

Section IX - Regulatory and Other Information

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.

Copyright ©
Public Health Agency of Canada, 2010
Canada

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