Hepatitis C virus (HCV) was first identified in 1989. It is an RNA virus with 6 major genotypes. Genotype 1 is the most common in Canada. It is estimated more than 245,000 people or close to 1% of Canadians are infected with HCV with about 1 in 5 unaware of their infection4,6. The Ontario Burden of Infectious Disease Study, 2010, lists hepatitis C first in the top 10 list of the most burdensome infections for Ontarians. There are more than 3,400 newly identified cases of hepatitis C each year in Ontario. The burden of hepatitis C appears to be greatest among men 44-50 years of age. Hepatitis C is still the most common cause for liver transplants1,2.
HCV is transmitted primarily by the parenteral route. Sources of infection include injection drug use and the sharing of injection and inhalation drug equipment, transfusions of blood or blood products prior to 1992, unsterile equipment used for tattooing and piercing, and needle-stick injuries6.
Injection Drug Use
According to Public Health Agency of Canada, injection drug use is associated with 61% of all newly acquired HCV infections6. There is the potential to become infected through the use of contaminated drug equipment, including spoons, water, wash, filters, ties, and devices used for snorting and smoking drugs like straws and crack pipes. The majority of newly identified infections are in individuals who are chronically infected from an exposure decades before2.
Previous Blood Transfusion
The receipt of blood and blood components, especially before 1992, is the second most important risk factor for HCV infection. In 1992 with the introduction of screening tests for anti-HCV, the risk of transmission from blood was approximately 1 in 100,000 per unit transfused. Since the introduction of the nucleic acid test in 1999, the current risk is estimated to be less than 1 in 2 million units transfused (source, Canadian Blood Services).
The risk of transmission as a result of a needlestick injury from a known positive source is estimated to be 1.8%3. In comparison, the risk of transmission from a needlestick for hepatitis B is 30% and HIV is 0.3%3,7.
Sexual transmission is uncommon in the general population; the virus is known to be present in the menstrual blood of infected women who can theoretically infect their sexual partners during intercourse. High-risk sexual behaviour such as multiple sexual partners, traumatic sexual intercourse, and anal intercourse, also increases the risk of transmission. Co-existing STIs including HIV infection are known to increase the risk of transmission6.
Mother to Child
Transmission from mother to child is possible and is considered a moderate risk1, 5. HIV confection is known to increase the risk of perinatal transmission of both viruses7. Breastfeeding is not likely to result in transmission of HCV infection unless the mother’s nipples are cracked or bleeding1.
HCV infection has also been associated with organ transplantation, renal dialysis, unsterile tattooing and household contact such as sharing razors or toothbrushes of an infected family member. Immigrants may arrive to Canada infected from their home countries through medical and/or ritual procedures1, 4, 6.
The incubation period for HCV averages 6 to 9 weeks with a range of two weeks to six months. The period of communicability is from one or more weeks prior to beginning of the acute clinical stage and persists in most people indefinitely. Initial infection seldom causes symptoms. If symptoms develop, they may include anorexia, malaise, dark urine, abdominal pain, fatigue and jaundice. About 3 in 4 infected people will become chronically infected. These individuals are at risk of complications including cirrhosis, liver cancer, and liver failure which may develop over a period of 25 – 30 years1,2.
The diagnosis of HCV infection requires testing of blood for anti-HCV. The presence of antibody to hepatitis C indicates exposure to hepatitis C virus. An initial positive antibody result is confirmed through a supplemental antibody test. Both tests must be positive to confirm the presence of anti-HCV (anti-HCV will be positive within 4 -12 weeks after exposure). The positive predictive value of a confirmed anti-HCV test result is high, therefore, patients with positive results on the confirmatory test should be considered to have HCV infection.
PCR testing can diagnose infection earlier than anti- HCV (2 to 4 weeks post exposure) 5 but false negatives can occur.
If anti-HCV is positive and the PCR test is negative, repeat testing is recommended in 6 to 12 months to rule out a transient decline in viral load and to confirm viral clearance.
Patients with chronic HCV can be treated with a combination of peginterferon and ribavirin. Treatment success depends on many host and viral factors including age, comorbidities, and genotype.
In 2011 Health Canada approved two protease inhibitors to be used in conjunction with pegylated interferon and ribavirin for treatment of patients with genotype 1 4, 5. The addition of protease inhibitors has resulted in higher cure rates and shorter treatment duration4.
Patients with HCV infection require support and counseling on ways to reduce liver damage, transmission to others and/or re-infection, and how to live well with hepatitis C5. Newly diagnosed patients require investigation to establish the most likely source of the infection and to prevent transmission to others.
HCV infection requires reporting to the local health department. Staff are available to provide additional counseling and review risks. Patient fact sheets are available in print and online. In managing a patient with HCV infection, it is important to discuss past blood donations, testing for other blood borne diseases and vaccination to protect against hepatitis A and B. Both hepatitis A and B vaccinations are free to patients with hepatitis C, and are available to order through the Middlesex-London Health Unit by calling 519 663-5317 ext.2236. Please note, the combined hepatitis A and B vaccine (TwinrixTM) is not currently publically funded.
Alcohol: Excessive alcohol intake combined with chronic viral hepatitis C can impair liver regeneration and promote fibrosis. Ideally, alcohol should be avoided.
Blood Donations: HCV-positive individuals should be instructed not to donate blood, tissues, or semen. Solid organ donations are acceptable. Patients should also be asked about donations made when they may have been infected and if they received blood or blood products as a possible source of infection. All relevant information should be reported to Canadian Blood Services.
Injection Equipment: Individuals should be informed not to share needles, syringes or other drug paraphernalia such as spoons, straws, crack pipes, filters and cookers. Injection equipment should be disposed of carefully. Sharps must be placed in a hard plastic shell container or metal tin can with a tight fitting, puncture proof lid. Needle exchange is available at the four following locations:
- Regional HIV/AIDS Connection 186 King St, Unit 30 London 519 434-1601
- Middlesex-London Health Unit, 50 King Street, London, 519 663-5446
- Needle Exchange Outreach Worker Mobile Service 519 851-3548
- My Sisters Place (Females Only), 566 Dundas St. London 519 679-9570
Note: Injection equipment cannot be disposed of in municipal garbage.
Sexual Transmission: Individuals with multiple sexual partners should be counseled about safer sex practices including use of barrier protection like condoms during all types of sexual intercourse. They should be advised to inform sexual partners if there is a risk of infection (for example, if barrier protection has not been used). Contact tracing of past sexual partners is not currently recommended. The risk of sexual transmission is increased by practices involving trauma, menstrual blood, or anal intercourse. Safer sex means not having sex or always using condoms/barrier protection during vaginal, anal, and oral sex.
Individuals should be encouraged to discuss their hepatitis C positive status with their long term partner as there is a small risk of transmission during intercourse. The partner should be counselled about their risk and should be offered testing for HCV.
Household Transmission: Any open wounds should be covered and instruments that may be contaminated by blood, such as razor blades and/or toothbrushes, should be confined to the infected person’s own personal use. It is not necessary to avoid close contact with family members or to avoid sharing meals or utensils that have been washed.
Perinatal Transmission: Pregnancy is not contraindicated in HCV-infected individuals. Pregnant women with cirrhosis should be referred to a specialist with expertise in high risk obstetrical care. Antibody testing of the infant born to a mother with hepatitis C should be done after 12 to 18 months of age when it is presumed maternal antibody has cleared. PCR testing can detect infection in the baby earlier than 18 months. There is no evidence breast-feeding transmits HCV from mother to baby, though breast-feeding should be avoided if the mother’s nipples are bleeding or cracked5.
Other Blood tests: Bloodwork including HCV-RNA, liver enzymes (ALT, AST, T-Bili, GGT, INR, Albumin), HBsAg, anti-HBs, anti-HBc, anti-HAV, and HIV should be ordered if not already done. Lab requisitions can be found online on the Public Health Ontario Website. If your patient is positive for HCV RNA, consider a referral to an experienced colleague (ie, hepatologist, infectious disease specialist or family physician with experience in HCV management).
Hepatitis A & B Vaccines: Hepatitis A and hepatitis B vaccinations are recommended for all HCV-positive individuals and are provided free of charge. The combined hepatitis A and B vaccine (TwinrixTM) is not publically funded. These vaccines can be ordered through the health unit by calling 519 663-5317 ext2336. Please specify publically funded vaccines.
|Canadian Liver Foundation
Phone: (519) 659-0951
For more information call the Middlesex-London Health Unit, Communicable Disease and Sexual Health Services at 519 663-5317 ext 2330.
Last modified on: November 5, 2015