Offering Testing for Hepatitis B and C in Primary Care. Presentation 3. October 2017

Transcription

1 Offering Testing for Hepatitis B and C in Primary Care Presentation 3 October

2 Learning Outcomes Participants will be able to: Undertake a pre test discussion for Hepatitis C and Hepatitis B testing to ensure informed consent is obtained Implement strategies in practice to maximise uptake amongst those at risk Interpret Hepatitis C and Hepatitis B serology results Page 1 1

3 Raising the issue of Hepatitis B and C testing Normalise the request Avoid stigmatising and blaming language Emphasise the benefits of testing for the individual Page 2 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. 2

4 Testing normalising testing suggested approaches Your tests have shown some damage to your liver and it is important that we work out why this is happening. There are many causes of this damage, including viral infections called Hepatitis B and Hepatitis C. These are treatable infections and I recommend we test for them in these circumstances Page 3 You need to find your own language and phrases that suit you. 3

5 Testing avoiding stigmatising and blaming language People who have used drugs, even if it was a long time ago, are at higher risk of certain viral infections including Hepatitis C, Hepatitis B and HIV. All of these are now treatable infections and we recommend routine testing for them. Would you agree to us taking these tests? Page 4 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. 4

6 Testing benefits of Testing Emphasise the following: Allows access to treatment which can control or cure infection Helps you to avoid future risk to yourself or others close to you Can allay anxiety if you are worried you June be infected Allows you to take measures to help protect liver if infected with Hepatitis B or C Page 5 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. 5

7 Testing pre test discussion Remember informed consent not counselling! Three essentials: 1. Explain what you are testing for and the benefits of testing to that individual 2. Allow opportunity to ask questions (and be able to answer them) 3. Explain how and when they will get the results Page 6 These essentials are based on the UK National Guidelines for HIV Testing 2008 published by BHIVA 6

8 Testing other issues Window period length of time after infection that it takes for a test to show a positive result Hepatitis C 3 months Hepatitis B 3 6 months (HIV 4 weeks 3 months) Test and repeat test after window period rather than delay testing Page 7 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. 7

9 Testing other issues (cont.) What to test for? As the risks overlap it is sensible to test for Hepatitis C, Hepatitis B and HIV at the same time Use published material at pre test discussion Available from Hepatitis C Trust and printpublications Hepatitis Scotland andresources/resources/living hepatitis c patient booklet The British Liver Trust ( Page 8 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. 8

10 Testing other issues (cont.) Patient anxiety whilst awaiting result Offer support and signpost to organisations such as the Hepatitis C Trust and Hepatitis Scotland Informing others Discuss who they should tell about having the test and who they do not have to tell at this stage Page 9 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 organisations during 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. 9

11 Testing how often to test for Hepatitis B and C? If a one off exposure to infection, check about window period and if tested after that then no more testing is required If recent exposure, test after the window period (6 months) Immunise against Hepatitis B no further testing required for Hepatitis B All active drug users offer 6 12 monthly testing for Hepatitis C (and HIV) consider even if not disclosing injecting/sharing Page 10 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. 10

12 Testing getting the result Arrange appointment at pre test discussion stage. Ideally done by the person who undertook pre test discussion (and took blood samples) Invite patient to have someone with them when they get the result. Use as a harm reduction opportunity Page 11 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. 11

13 Testing maximising uptake Perform test your self don t expect someone to come back for another appointment Offer the test again even if previously declined emphasise the benefits. Consider offering testing to all new registrants from areas of high prevalence Offer to all drug users even if no history of injecting Use Dried Blood Spot (DBS) testing if venous access hard Page 12 In view of the population that we are targeting 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 takenas a refusal to test. Emphasise the benefits of testing. 12

14 Testing taking the test Single venous blood test can be used to test for Hepatitis B, Hepatitis C and HIV Clearly state clinical history and risk factors on request from including estimated date of last possible exposure DBS testing available in Scotland for diagnosis of all BBV using finger prick capillary blood If using DBS all five target circles must be completely covered in blood Page 13 Brown tube, single virology form. 13

15 Dried Blood Spot (DBS) testing Dry blood spot testing Hepatitis C antibody testing Hepatitis C RNA detection OR Antigen detection HIV antibody testing Hepatitis B surface antigen detection Hepatitis B core antibody testing Page 14 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. 14

16 Interpreting the results Make sure you give the person the correct result! Test your previous knowledge gained from elearning module now! Write down answers to the questions on the following 3 slides and check your knowledge at end of this section. Page 15 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. 15

17 Test your previous knowledge Working it out in practice what does it mean if? Hepatitis C antibody test positive Hepatitis C PCR test negative Hepatitis B surface antigen positive Hepatitis B core antibody negative Page 16 Please see slide 30 for the answer. 16

18 Test your previous knowledge Working it out in practice what does it mean if? Hepatitis C antibody test negative Hepatitis B surface antigen negative Hepatitis B core antibody positive Page 17 Please see slide 30 for answer. 17

19 Test your previous knowledge Working it out in practice what does it mean if? Hepatitis C antibody test positive Hepatitis C PCR test positive Hepatitis B surface antigen negative Hepatitis B core antibody negative Page Please see slide 30 for answer. 18

20 Interpreting the results Hepatitis C Initial test is serology for antibodies to Hepatitis C Hepatitis C antibody positive it shows exposure to the virus but not whether infection is ongoing A positive result will automatically be sent for PCR (or in some areas an ANTIGEN) test Page 19 Antigen testing in Lothian and starting in Glasgow and other areas. 19

21 Interpreting the results Hepatitis C PCR is the key! PCR test viral load test Detects viral RNA by amplification and a positive PCR test indicates chronic infection Only Hepatitis C PCR +ve patients are chronically infected Also used to determine efficacy of treatment and cure Page 20 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. 20

22 Interpreting the results Hepatitis C antigen test In some areas an ANTIGEN test is carried out to diagnose Hepatitis C In some areas it replaces the PCR test to confirm ongoing infection If the antigen test is positive it shows chronic infection with Hepatitis C If the antigen test is negative the patient needs a PCR test to double check result (another sample) Page 21 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. 21

23 Interpreting the results Hepatitis C negative tests If the test comes back Hepatitis C antibody negative the patient has not been infected with Hepatitis C (however remember the window period!) Should be advised that they have not been infected but if they put themselves at risk again they could become infected Page 22 These are the people who do NOT have evidence of Hepatitis C infection. 22

24 Interpreting the results Hepatitis C negative tests (cont.) If the test shows Hepatitis C antibody positive but the PCR test is negative: They have been infected with Hepatitis C, but have cleared the virus They are not immune to Hepatitis C and could become infected again and it may become a chronic infection next time If the test shows Hepatitis C antibody positive but the antigen test is negative: Lab may request EDTA (red) tube for PCR testing to confirm the negative result Page 23 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. 23

25 Interpreting the results Hepatitis B Must establish two key factors: Is the person infected currently? If not currently infected, is the person immune? Three tests can answer these questions: Hepatitis B surface antigen (HBsAg) Antibody to HBSsAg (anti HBsAg) Antibody to HB core antigen (anti HBcAg) Page 24 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. 24

26 Diagram of Hepatitis B virus Page 25 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. 25

27 Interpreting the results Hepatitis B surface antigen: a viral component Hepatitis B surface antigen (HBsAg) is detected in current infection. (>6 months = chronic infection) If this is positive the patient has an ongoing Hepatitis B infection If this is negative the patient does not have an ongoing Hepatitis B infection Page 26 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. 26

28 Interpreting the results antibody to Hepatitis B surface: an immune response Hepatitis B surface antibody (anti HBs) If this is positive it means that the patient has had a past infection or been immunised and is now immune to Hepatitis B If this is negative it means that they have not had a past infection, and if the antigen test is also negative, they need immunised Page 27 An immune response from a past infection or after immunisation. If it is not present the patient should not be considered immune. 27

29 Interpreting the results antibody to Hepatitis B core: an immune response Hepatitis B core antibody (anti HBc) If this is positive it means that the patient has had a past infection and may now be immune to Hepatitis B If this is negative it means that they have not had a past infection, if the antigen and surface antibody tests are also negative, they need immunised Page 28 An immune reaction to the middle of the virus, only occurs after an infection NOT after immunisation. 28

30 Test your previous knowledge Working it out in practice what does it mean if? Now please check your answers Page 29 Slide 17 Hepatitis C antibody test positive Hepatitis C PCR test negative Hepatitis B surface antigen positive Hepatitis B core antibody negative 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. Slide 18 Hepatitis C antibody test negative Hepatitis B surface antigen negative Hepatitis B core antibody positive 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 no evidence of exposure to Hepatitis C infection. 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 immunisation. 29

31 Interpreting Hepatitis B antibody results summary If the Hepatitis B surface antigen test is negative then: Anti HBc Anti HBs Interpretation and action Never had Hepatitis B and no immunity immunise + + Past infection no action as now immune + Past infection no action as now immune + Past immunisation complete the course or reimmunise unless certain fully immunised Page 30 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. 30

32 Group work testing The group facilitator will present you with three case studies on Testing Each case study has a number of questions to be addressed For each case please discuss and capture main points of responses on flip chart for feedback at end of this session Page 31 31