P161 Missed opportunities? Reviewing Hhepatitis D testing in new hepatitis B diagnoses in Northern Ireland

<h3>Background</h3> Current NICE guidelines for Hepatitis B virus (HBV) recommend that all newly diagnosed patients should be tested for Hepatitis D virus (HDV) in primary care. In Northern Ireland (NI), all HBV diagnostic testing is performed by the Regional Virology Laboratory (RVL). All new cases of HBV are referred to a centralised, regional viral hepatitis clinic based in Belfast. Prior to 2022, fewer than 10 HDV tests were sent annually, with none returning a positive result. A cluster of new HDV cases was identified in 2022 leading to a look back exercise. A new protocol was introduced in June 2023 to ensure all new HBV patients were tested for HDV at first clinic visit. <h3>Aim</h3> The aim of this review was to evaluate compliance with this new protocol in the 12 months following its implementation and to identify obstacles to testing <h3>Method</h3> A list of all newly diagnosed HBV cases between 1/6/23 and 31/5/24 was compiled following review of RVL records. The medical records of these patients were subsequently examined for evidence of referral to/attendance at the regional viral hepatitis clinic. Where patients had attended, evidence of HDV testing was sought in RVL records. <h3>Results</h3> 120 new HBV cases were identified during the study period. Eleven patients were excluded from the study as a result of insufficient demographic data to identify the patient. Of these remaining 109 patients, 107 were referred to viral hepatitis clinic, with 80 (74.8%) patients having been seen in clinic to date. Of the 80 patients seen in clinic, 35 (43.8%) patients were tested for HDV. In two patients where tests were sent, these were rejected for laboratory reasons. These patients did not have repeat tests sent. No positive HDV results were returned <h3>Conclusion</h3> Despite an established protocol, only 43.8% of new HBV cases were tested for HDV upon attendance at a regional viral hepatitis clinic. Potential obstacles to testing include reduced awareness of the protocol amongst staff at the clinic and also that, whilst other blood tests were requested electronically as part of a panel, HDV testing required an additional, separate, paper form. We recommend that reflex testing for HDV in newly diagnosed HBV cases should be considered in NI, which is a low prevalence region for HDV.