Notes Offering Testing for Hepatitis B and C in Primary Care

Transcription

1 Health Protection Scotland/NHS Education Scotland January 2016

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3 Testing for these viruses needs to be part of routine clinical practice if we are to reduce the number of people with undiagnosed infection. The request should be normalised. Be aware that the people who are at risk are in groups who are often stigmatised and excluded - injecting drug users, MSM, immigrants and we need to make sure that we are not seeming to blame them for their risk of infection. The benefits of having a test clearly outweigh any perceived risks and we need to be very clear what the benefits of knowing your diagnosis are when obtaining informed consent to test.

4 You need to find your own language and phrases that suit you.

5 NOT - drug users can catch all sorts of infections so I am going to test you for Hepatitis C and HIV. NOT - your country has lots of Hepatitis C infection so we had better test you for it.

6 You are much more likely to do harm by not testing someone for a blood borne virus. You do need to get informed consent to taking the test.

7 These essentials are based on the UK National Guidelines for HIV Testing 2008 published by BHIVA

8 People need to know whether the test will give them a definitive result - or it they will require a repeat test to ensure that they are not infected if the first test comes back negative. This situation arises if they test within the window period that is the time during which antibody levels may not high enough in the blood stream for the current tests to detect. The length of time varies between the different BBV infection.

9 Risk of one BBV infection means that you have some risk for the others and it is often sensible to test for Hepatitis B, Hepatitis C and HIV on the same test, consenting the patient for all three tests. Good written materials are available to to back up the oral information that you are giving.

10 Waiting for the result is often the most anxious time for people, a test may take a week to come back in primary care. Offer support yourself and from other organisationsduring this time. Find out who your local voluntary organisation offering support to patients with BBV infections are. People often start to worry about who they need to tell that they are having a test. If they tell someone they are testing they are likely to have to tell them the result so they need to consider that.

11 This is particularly an issue for Hepatitis C as there is no immunity from previous exposure and no vaccine to protect them. So all injecting drug users who continue to inject should be offered regular repeat testing - even if they are not disclosing sharing of equipment. Some people would recommend repeat testing of all drug users as they may not disclose injecting at all and there is a risk from snorting drugs.

12 As increasing amounts of hepatitis tests are performed it may not be practical to give all results face to face. It is acceptable to give negative results on the telephone although a harm reduction/prevention opportunity may be missed Positive results should be given in person, ideally by the person who did initial discussion, but should be done by any appropriately qualified professional at next contact, rather than risk missed opportunity. Harm reduction regardless of result is of prime importance.

13 In view of the population that we are targetting it is best to take the opportunity to offer and carry out testing whilst they are with you. Bringing people back to appointments just for testing results in high non-attendance rates due to the other priorities in peoples lives. Non-attendance should not be taken as a refusal to test. Emphasise the benefits of testing.

14 Brown tube, single virology form.

15 Measuring the incidence, prevalence and genetic relatedness of Hepatitis C infections among a community recruited sample of injecting drug users, using dried blood spots. Hope VD, Hickman M, Ngui SL, Jones S, Telfer M, Bizzarri M, Ncube F, Parry JV. J Viral Hepat Apr;18(4): doi: /j x.

16 Ask them to look at examples of results in their pack and write down what they think the result mean - we will come back to these at the end of the talk.

17 Please see slide 30 for the answer.

18 Please see slide 30 for the answer.

19 Please see slide 30 for the answer.

20 Antigen testing in Lothian and starting in Glasgow and other areas.

21 People are still telling patient who are Hepatitis C antibody positive but PCR negative that they have Hepatitis C infection. PLEASE DO NOT DO THIS - ONLY PATIENTS WHO ARE PCR OR ANTIGEN POSITIVE HAVE ONGOING INFECTION.

22 In many areas the patient has an initial antibody test and if this is positive an ANTIGEN test is performed instead of the PCR test, if the antigen test is positive the patient has ongoing Hepatitis C infection. If the antigen test is negative the lab requests that another blood sample is taken in a red EDTA tube on which PCR test is performed to confirm no active infection. This second test is required because the lab is concerned about false negative antigen tests. The antigen test is cheaper and quicker than the PCR test. It may show an active infection earlier than the antibody test but has a higher false negative rate than the PCR test.

23 These are the people who do NOT have evidence of Hepatitis C infection

24 Antigen tests are not so straight forward in this situation and a negative antigen test associated with a positive Hepatitis C antibody test requires confirmation with a PCR test.

25 Two questions - three tests to answer them. Hepatitis B surface antigen is a viral particle,the other two tests are for antibodies (i.e. the immune response) to viral elements.

26 Surface antigen on the outside of the virus is released into the blood stream during an infection and also evokes an immune response. Artificial surface antigen is uses in the Hepatitis B immunisation. Core antigen in the middle of the virus also evokes an immune response.

27 Surface antigen is a bit of the virus so if it is detected in the blood stream there must be an active infection.if it is not present there is no active or ongoing infection.

28 An immune response from a past infection or after immunisation. If it is not present the patient should not be considered immune.

29 An immune reaction to the middle of the virus, only occurs after an infection NOT after immunisation.

30 Slide 17 Hepatitis C antibody test positive Hepatitis C PCR test negative Hepatitis B surface antigen positive Hepatitis B core antibody negative Slide 18 Hepatitis C antibody test negative Hepatitis B surface antigen negative Hepatitis B core antibody positive This shows previous exposure to Hepatitis C but no evidence of active infection, the patient is not immune to Hepatitis C. The patient has active Hepatitis B infection and requires urgent referral to Infectious Diseases or a Liver Unit. This shows no evidence of exposure to Hepatitis C infection. The patient does not have active Hepatitis B infection but has had previous infection and is immune to Hepatitis B infection now. They are not immune to Hepatitis C infection. Slide 19 Hepatitis C antibody test positive Hepatitis C PCR test positive Hepatitis B surface antigen negative Hepatitis B core antibody negative This shows active infection with Hepatitis C as the PCR is positive. There is no evidence of exposure to Hepatitis B infection and they are not immune, they require immunistation.

31 Emphasise that these results are for patients who are known to be Hepatitis B surface antigen negative, that is they do not have a current Hepatitis B infection.

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