Identifying Hepatitis C And Testing At Risk Patients

Main Category: Liver Disease / Hepatitis
Article Date: 29 Jun 2004 - 15:00 PDT

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TESTING

Hepatitis C is a blood-borne virus that can cause significant damage to the liver. It is estimated that approximately 200,000 people in England have chronic hepatitis C infection, which can lead over time to cirrhosis and primary liver cancer. The majority of those infected are undiagnosed.

The effects of infection vary from one person to the next. Some people will clear the virus at the acute stage, but about 60-80% of people develop chronic infection. Of these, some will remain well and never develop liver damage and many will develop only mild to moderate liver damage, 5- 20% of chronically infected people will progress to cirrhosis of the liver over a period of about 20 years, and a small proportion of those with cirrhosis will progress to primary liver cancer.

WHAT ARE THE SIGNS AND SYMPTOMS?

Most people do not experience any symptoms when they become infected. Some people may feel briefly unwell and in rare cases may become jaundiced (yellowing of the skin and eyes). Many people with chronic hepatitis C infection will have no symptoms, while others will feel unwell in varying degrees WHY SHOULD I OFFER TESTING?

There are several important reasons for offering hepatitis C testing to a patient who may have been at risk of infection or who shows evidence of liver disease that may indicate infection.

• Testing provides the opportunity to refer those infected to a specialist for further investigation and treatment, if appropriate

• Testing provides the opportunity for discussing current potentially harmful patterns of behaviour such as injecting drug use or excessive alcohol consumption

• Testing can also allay anxiety

• Testing for hepatitis C should form part of the investigation of patients with unexplained abnormal liver function tests, or with unexplained jaundice

HOW IS HEPATITIS C TRANSMITTED?

Current epidemiological evidence suggests that there are groups who should be offered hepatitis C testing and groups for whom testing is not recommended.

• Hepatitis C is transmitted mainly via direct blood-to-blood contact. The main route of transmission is by sharing equipment for injecting drug use, mainly via blood contaminated needles and syringes. Spoons, filters and water may also transmit infection

• There is a risk to recipients of blood transfusions (before September 1991) or blood products (before 1986) in the UK . For example, there is a high prevalence of HCV in people with haemophilia who received untreated clotting factors before 1986. All blood and blood products in the UK are now screened

• Mother to baby infection does occur, but this is very rare, with upper estimates of about 6%. However this increases to 14-17% when there is co infection with HIV

• Sexual transmission of hepatitis C is possible but uncommon. Estimates or sexual transmission of hepatitis C are less than 5% in regular sexual partners

• Transmission can occur through medical and dental procedures abroad, in countries hepatitis C is common and where infection control may be inadequate

• Health care workers (and to a lesser extent, other workers, such as police, prison staff and social workers), may be at risk of HCV infection from occupational injuries, such as needle stick injuries

• There is a risk from tattooing, ear/body piercing and acupuncture if blood-contaminated with unsterile equipment is used

• There is some evidence that transmission may occur through sharing toiletry equipment such as toothbrushes, razors, and other items that may be contaminated with blood

GROUPS TO WHOM HEPATITIS C TESTING SHOULD BE OFFERED

• People who have ever injected drugs in the past

• People who are currently injecting drug users

• People who have received transfused blood in the UK prior to September 1991 or blood products prior to 1986

• Recipients of organ and tissue transplants in UK before 1992 or abroad in countries where hepatitis C is common and donors my not have been screened

• Babies born to mothers known to be infected with HCV

• Children of mothers found to be infected with HCV

• Regular sexual partners of patients infected with HCV

• Patients with unexplained abnormal liver function tests

• Health care workers accidentally exposed to blood where there is a risk of transmission of hepatitis C infection

• Anyone who has received medical or dental treatment in countries where hepatitis C is common and infection control may be poor (this will include blood transfusions and blood products where donations are not screened for hepatitis C)

• People who have had tattoos, body piercing and other forms of skin piercing where infection control procedures are poor

TESTING OF THE GROUPS BELOW SHOULD TAKE PLACE AS PART OF THEIR HEALTH CARE

• Patients with renal failure on dialysis

• HIV infected patients

GROUPS FOR WHOM HEPATITIS C TESTING IS NOT RECOMMENDED

• Pregnant women not in one of the groups mentioned above

• All health care workers

• Individuals with multiple sexual partners

• Individuals who use cocaine intranasally

For further information please refer to Hepatitis C: essential information for professionals and guidance on testing, which can be downloaded from the resources section of the website

WHAT SCREENING TESTS ARE AVAILABLE?

If you think someone may be at risk you can offer an initial antibody test to identify if the patient has ever been infected with hepatitis C.

About 20%-40% of people who have been infected with hepatitis C will clear the virus at the acute stage. However, in general these people will still have positive antibody results.

It can take up to 3 months for antibodies to hepatitis C to become detectable. Therefore, in patients whose exposure has been recent and whose first test is negative, the hepatitis C antibody test should be repeated 3 months after the last possible exposure in order to avoid misdiagnosis during this "window period".

If the antibody test is confirmed as positive, the next steps are to establish if the virus is still present, and if so to diagnose the extent of the underlying liver disease. To do this specialist tests are required some of which may be carried out in primary or secondary care according to local arrangements

HCV RNA DETECTION TEST (e.g. a PCR test)

This will identify current circulating virus. More sophisticated tests are available to identify the genotype of the virus and to assess the viral load. These latter tests are usually only carried out if a patient is to be offered antiviral therapy

LIVER FUNCTION TESTS (LFTs)

These tests should be used to screen for evidence of hepatitis

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