Download Factsheet: Hep C Testing Overview

Factsheet:
Hep C Testing Overview
For more information about anything in this factsheet, phone
the Hepatitis Infoline on 1800 803 990 or go to www.hep.org.au
Diagnosis and monitoring
There are a number of testing procedures relating to hepatitis C (also called hep C) and hepatitis
C virus (also called HCV). Generally, they relate to:
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Finding out if a person has hep C (diagnosis)
Monitoring someone’s level of liver damage
Predicting someone’s response to hep C treatment
Monitoring someone’s response to hep C treatment.
Principles of hep C testing*
The eight basic principles that guide hep C testing in Australia are:
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Confidential, voluntary testing with informed consent and post-test discussion as
fundamental to Australia’s response to hep C
Testing is critical to understanding the epidemiology of hep C infection in the community;
Testing must be accessible to all those who are or have been at risk of hep C infection;
Testing will be of the highest possible standard and provided in a timely manner;
Testing is of benefit to the person being tested;
Testing can be critical to interruption of transmission and can support harm minimisation;
Testing to monitor people with hep C before, during and after treatment is an integral part
of their care; and
People should not be denied testing because of fear of having their name associated with
a hep C test (e.g. in a small community where confidentiality is harder to maintain). Deidentified testing should be considered to protect privacy where relevant.
Who should consider being tested for hep C?*
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People with a history of injecting drug use
People who are or have ever been incarcerated
Recipients of organs, tissues, blood or blood products before February 1990 in Australia,
or before the implementation of mandatory screening of blood donors in other countries
(or at any time where this is not the case)
People with tattoos or skin piercings
People born in countries with high hep C prevalence
Aboriginal and Torres Strait Islander populations
Sexual partners of people with hep C
Children born to hep C-positive mothers
Transmission and infection control in healthcare settings
Informed consent for testing*
Informed consent for testing means that the person being tested agrees to be tested on the basis
of understanding the testing procedures, the reasons for testing and is able to assess the
personal implications. Informed consent is required for hep C testing, except for rare occasions
when a legal order is made for compulsory testing or in emergency settings. On these rare
occasions where informed consent cannot be attained, pre-test provision of all appropriate
information to the person should still take place.
The person performing the test should use their clinical judgment in securing informed consent.
This should be based on their understanding of the context in which the test is being performed,
taking into account:
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the factors which indicate a need for testing such as clinical presentation, risk exposure,
prevalence and individual initiation; and
an assessment of the understanding of the hep C testing process and the consequences
of the result to the person being tested.
General principles of professional conduct apply in the case of hep C testing and informed
consent should not be sought from sexual partners or family members of the person being
tested.
In the case of testing a child or person who is incapable of giving consent (perhaps due to mental
illness or cognitive disability) then the responsibility for consent rests with the guardian or other
person/agency legally authorised to make such decisions on their behalf.
People involved in hep C testing must use whatever additional support is necessary to assist the
person considering testing to become adequately informed. This process involves a referral to
the support groups, including access to telephone interpreters (available nationally for use by
private and public health care professionals). Culturally relevant information should be provided
when seeking informed consent and providing results.
The person being tested needs to be made aware of confidentiality considerations and
protections.
Conveying hep C test results*
The process of conveying a hep C test result (previously called post-test counselling) to the
person being tested, irrespective of the specific result, is affected by the type of test performed,
the setting of the consultation, and testing and the extent, if any, of additional testing required in
determining the true hep C status of the person. The person who requests the test is responsible
for ensuring that the delivery of the test result is carried out in a setting conducive to discussing
the implications of the result and addressing the issues that the result raises (see section 5.2).
Where an anti-HCV test has been the only test requested, discussion of the need to progress to
viral studies will need to be addressed in the process of informing the person of their actual hep
C status. In presenting results to people from countries where English is not the primary
language, interpreter services should be accessed.
Conveying a negative result
This may be a negative anti-HCV result or a negative HCV RNA result. The decision on how a
negative hep C test result is provided (e.g. in person, by phone, etc.) should be based on the
clinical judgement of the person responsible for conveying the result. This assessment should
take into account the psychological capacity of the person being tested to deal with the outcome
of testing and his/her understanding of the testing process as evident at the time of the sample
collection. It is imperative that the meaning of a negative result is fully understood and that the
person being tested receives appropriate information about harm reduction in relation to the
spread of BBVs. Further testing following a negative result (anti-HCV or HCV RNA) is indicated
in persons who may be in:
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A window period prior to seroconversion (negative anti-HCV or HCV RNA in a high-risk
situation); and/or
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The situation of having a known previous infection with persistent anti-HCV positivity but
a negative HCV RNA. In this latter situation, a single HCV RNA negative result is highly
likely to reflect viral clearance. If liver tests remain abnormal or if re-exposure is possible,
two HCV RNA results 6 months apart should be negative before assurance is given that
the infection has been cleared.
It is imperative that the clinician makes all attempts to ensure that the result is being provided to
the person who was tested. This includes:
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Confirming the person’s identity;
Making repeated contact to ensure the person is aware of the availability of the result;
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Documenting all efforts to contact the person.
Conveying a confirmed positive result
This may be a positive HCV Ab or a positive HCV RNA result. Both will have a significant impact
for a person and their clinician. Laboratories commonly provide information and the opportunity
for consultation to assist the requesting clinician at the time of diagnosis. A positive result should
always be provided in person by the clinician, except in extenuating circumstances where, for
example, it is suspected that the person who has been tested may not return for the result and/or
may engage in risk behaviour(s) based on the wrong assumption that they are HCV negative. A
positive HCV Ab result will need to be informed by further testing for the HCV RNA (or HCV Ag)
to clarify whether the person is still infected or has cleared the virus.
The discussion when conveying a positive result should include:
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Giving the test result in person and in a confidential manner that is sensitive and
appropriate to the gender, culture, behaviour, language and literacy level of the person
who has been tested;
Providing information on further testing that may be required to clarify the situation
Assessing the need for and providing information about support mechanisms and making
provisions for immediate referral to a support agency as required. Providing information
on the next steps in staging hep C disease in those who are HCV RNA positive and
discussing potential treatment options. It may be necessary to cover these issues over a
period of time, in which case a subsequent consultation should be arranged at the time of
diagnosis;
Disclosure strategies to partner, family and friends;
Legal obligations to disclose hep C status relevant to where the diagnosis is made; and
The transmission of hep C and how onward transmission may be prevented.
Referral for further support
The information and support needs of people who are preparing for diagnostic testing for hep C,
or have just received a test result are considerable and diverse. Information provided in a single
clinical consultation is often insufficient to meet their needs as understanding develops and
different personal factors arise over time. Community-based organisations including hepatitis
organisations, peer-based drug user groups and haemophilia organisations are well placed to
assist people who are newly diagnosed to better understand the hep C testing and diagnosis
process and provide appropriate support through this critical period. Providing referral to relevant
community-based organisations or if available, on-site peer support, to one or more of the
following organisations is therefore highly recommended when informed consent for testing is
being obtained and as appropriate at other stages of hep C testing and management process.
Liver function tests
General Practitioners (GPs) may recommend liver function testing if a patient reports feeling
unwell. These tests involve taking a sample of blood and looking for various substances
(enzymes) in order to determine what is happening in that person’s liver. They don’t look for hep
C, but can indicate whether a person’s liver is being damaged.
Antibody tests
A GP may recommend antibody testing if a patient reports past or current hep C risk factors, or
as a result of abnormal liver function test results.
Our bodies produce antibodies which float around in our blood and are part of our defence
against some germs and infections (our immune system). The hep C antibody blood test looks
for specific antibodies against the hep C virus. A positive result shows that a person has
contracted hep C some time recently or in the past.
In one in four cases, a person’s immune system is able to get rid of their hep C infection but they
will still carry antibodies. Because of this, a positive antibody tests result doesn’t necessarily
mean a person has an ongoing chronic infection. For more detail on antibody testing, see our
Antibody Testing factsheet.
PCR tests
These are tests that look for genetic material from the hep C virus and show whether or not the
virus is currently present in a blood sample.
The name “PCR” stands for polymerase chain reaction which is a technique of amplifying and
measuring bits of the hep C virus genetic makeup – and is sometimes called HCV RNA testing.
There are three types of PCR test which provide different information about someone’s hep C
infection:
PCR viral detection test
The PCR viral detection test is mainly used to confirm antibody test results. If someone is PCR
positive, then it indicates they have a current hep C infection. It is also used following treatment
to show if someone has been cured.
PCR viral load test
This test measures the amount of virus in someone’s blood.
PCR viral genotype test
This test can determine people’s hep C genotype (see below). This is important if someone is
considering hep C antiviral treatment as their genotype determines their length of treatment and
whether or not treatment is likely to succeed.
Although people usually talk about hep C as if it were a single virus, there are about six different
main genotypes (strains). All hep C genotypes affect the liver the same way and, generally, one
genotype is no better or worse than others in regards to causing liver damage.
PCR tests cost $100 or more but are available free-of-charge through Medicare in certain
situations. For more info, contact the Hepatitis Infoline. Also see our PCR availability and PCR
and transmission factsheets.
Window periods
With antibody tests, it takes up to 12 weeks after a risk exposure to be sure the test will return an
accurate result.
With PCR tests, it takes two weeks after a risk exposure to be sure the test will return an
accurate result. Because of this shorter window period (and more conclusive result), PCR tests
are also used four weeks after a needlestick injury to test whether or not someone has caught
hep C.
The window period for PCR testing babies is eight weeks (with follow up PCR test at 12-14
weeks and an antibody test at 18 months).
Fibroscan
Fibroscan tests use advanced ultrasound technology to assess the stiffness of a person’s liver
(the stiffer the liver, the more likely that fibrosis or cirrhosis exists).
Fibroscan takes only 15 minutes and does not involve needles or other invasive instruments. A
follow up fibroscan test will show whether or not a person’s liver stiffness is increasing,
decreasing or remaining stable. Also see our Two Hep C Questions booklet.
APRI test
APRI (AST to Platelet Ratio Index) is a liver fibrosis assessment tool. It is a simple biochemical
marker that can be calculated from routine blood test results. There are three fields in the
calculator, the patient's AST (aspartate aminotransferase) level, the testing laboratories' upper
normal AST limit, and the patient's platelet count. The formula used is APRI = AST (IU/L) / AST
upper normal limit (IU/L) /Platelet count (109/L) x 100
The APRI test is recommended for patient assessment for hep C treatment – where fibroscan
(above) is not readily available. Those patients who have lower levels of fibrosis can be treated
via their GP; those patients with higher levels of fibrosis are treated via specialists.
Liver biopsy
A liver biopsy involves taking a small sample of someone’s liver and examining it under a
microscopic. A biopsy, properly carried out, gives the most accurate report on the condition of
the liver and may be recommended for medical reasons. Also see our Liver biopsy and fibroscan
factsheet.
* The sections marked with asterisks are abridged from the 2012 National Hepatitis C Testing
Policy.
For more information about anything in this factsheet, phone the Hepatitis Infoline on 1800 803 990
or go to www.hep.org.au
This factsheet was developed by Hepatitis NSW. It was reviewed by the Hepatitis NSW Medical and
Research Advisory Panel. Special thanks to Professor Jacob George.
Last updated 21 Oct 2016