Hepatitis C (HCV)

Hepatitis C is an RNA virus that was the major cause of transfusion-associated hepatitis until blood screening assays were introduced. Six major genotypes of HCV have been defined and there are more than 50 subtypes.

The main groups at risk of infection are:

In certain immigrant populations, poor infection control practices during procedures have been responsible for many infections, for example, among Egyptians receiving chemoprophylaxis for schistosomiasis.

The role of sexual transmission is controversial. If sexual transmission does occur, it is at a very low level that makes it inappropriate to routinely recommend safe sex among long-term monogamous couples. Sexual transmission is likely to be more efficient where there is HIV co-infection and high HCV viral load.

The risk of transmission from an HCV-infected mother to her newborn is about 5%, if she is HIV negative. This increases to about 19%, if the woman is co-infected with HIV. Breastfeeding does not increase the risk of HCV transmission and need not be avoided, except if the mother is also infected with HIV. Breastfeeding should be suspended if the nipples are cracked or if the baby has broken mucosa or skin cuts in or near the mouth.

Acute infection: Most acutely infected patients are asymptomatic or have a mild illness. Jaundice occurs in fewer than 25% and 10–20% have only non-specific symptoms, such as anorexia, malaise, abdominal pain. In patients who experience acute symptoms, the illness typically lasts for 2–12 weeks. Severe acute hepatitis C is rare.

Chronic infection is common after primary infection with HCV. Only 15–25% clear HCV infection spontaneously within the first year. Symptoms are often absent, minimal, intermittent or nonspecific. Fatigue is commonly reported. Other symptoms include anorexia, nausea, abdominal discomfort and intolerance to alcohol and fatty foods. Up to one third of patients have a normal serum ALT and there is little correlation between the ALT level and the presence of symptoms. Extrahepatic manifestations can occur, for example, porphyria cutanea tarda (qv), lichen planus and vasculitic rashes associated with cryoglobulinaemia (qv).

The major consequence of HCV infection is progression to cirrhosis and its complications, for example, ascites, hepatocellular carcinoma. Progression to cirrhosis occurs in approximately 15–20% of those with chronic HCV infection after 15–40 years. The progression of chronic hepatitis C is accelerated by alcohol consumption and by co-infection with HIV and/or chronic HBV.

Several organisations have provided guidelines for who should be tested for HCV.

The US Center for Disease Control and Prevention (CDC) recommends that testing for HCV should be routine in patients at increased risk for infection, including those who:

Testing should also be performed, based upon the need for exposure management including:

In addition, the American Association for the Study of Liver Diseases recommends testing the following groups:

Routine testing is not recommended (unless an additional risk factor is identified) in:

An enzyme immunoassay (EIA) that detects antibodies against several HCV antigens is the first test used when screening patients suspected of having chronic HCV infection. In acute HCV infection, anti-HCV antibodies are detected in 50–70% of patients by the time symptoms develop and are usually present in the rest after a further 3–6 weeks. Immunosuppressed patients may not develop detectable anti-HCV antibodies. HCV antibodies are not protective, for example, against other strains of HCV. False-positive low-level reactivity may occur in the EIA test.

Patients with a hepatitis C antibody, detected on the initial screening EIA, have a second EIA assay performed which has a different set of antigens. If the initial screen is detected and the confirmatory assay is not detected, then the patient is said to have an ‘equivocal’ hepatitis C antibody result.

For patients with reactive EIA tests, a follow-up repeat serology test and a nucleic acid amplification test, to directly detect HCV RNA, are indicated.

Detection of HCV RNA by PCR confirms current infection with HCV. HCV RNA testing should be performed:

HCV RNA testing may be qualitative or quantitative. The initial test is usually a hepatitis C qualitative PCR test. If this is detected, then a hepatitis C quantitative test (viral load) is usually indicted. The viral load does not correlate with the extent of hepatitis, fibrosis or risk of disease progression. However, it does provide some prognostic value with regard to response to antiviral therapy.

Anti-HCV non-reactive/HCV RNA not detected:

Anti-HCV reactive/HCV RNA not detected:

Anti-HCV non-reactive/HCV RNA detected:

Anti-HCV reactive/HCV RNA detected:

Antiviral therapy is now recommended for all individuals with persistent infection, as indicated by the detection of HCV RNA in the blood. Several antiviral agents are available and have the potential to eliminate HCV in the vast majority of cases. It is still recommended that the infecting HCV genotype be established prior to treatment but is not essential due to the availability of pan-genotypic antivirals.

Hepatitis A and B vaccination should be offered to all susceptible patients with chronic hepatitis C.