LAUSR

S S83 The patient was treated initially with pulse methylprednisolone followed by tapered oral prednisone, and mycophenolate mofetil but transitioned rapidly with effect after 1 week to rituximab 1 g at day 0 and 14 due to severe oculopharyngeal involvement. LABD with predominantly mucosal involvement may be considered a variant of mucous membrane pemphigoid and requires a similar approach to treatment. Reference 1. Joseph TI, Sathyan P, Goma Kumar KU. Linear IgA dermatosis adult variant with oral manifestation: a rare case report. J Oral Maxillofac Pathol 2015; 19: 83–7. REVIEW OF LYOPHILISATION OF EXTERNAL QUALITY ASSURANCE PROGRAM MATERIAL Zoe Vayanos, Alexander Richardson, Kristie Chapman, Peter Graham 1The Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP), St Leonards, NSW, Australia; 2Department of Clinical Immunology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia Sample integrity is a critical factor in provision of external quality assurance (EQA) programs. As part of the RCPAQAPs initiative to ensure and improve the quality of our products, a revised stability testing procedure was implemented in 2018. The RCPAQAP’s Tryptase program displayed reduced stability when exposed to 37C for prolonged periods, although this could bemitigated when samples were lyophilised. In 2020, Tryptase EQA material was provided in lyophilised form, to be reconstituted at the time of testing. We reviewed performance within the RCPAQAPs Tryptase program in the 2 years prior to (2018–2019), and the two years following (2020–2021), the introduction of lyophilised material. Data was analysed using a one-way ANOVA with Tukey’s multiple comparison test, with no significant change in performance noted (CV% 8.1, 8.3, 7.7 and 7.2 respectively). Lyophilisation of samples had no effect on program performance while providing improved sample integrity. FRANCISELLA TULARENSIS: A CASE STUDY OF A MISIDENTIFICATION Mikaela Dewar, Abbey Davison, Kahlia Lane, Danielle Thompson, Brock Reitzer-Parks, Caitlin L. Keighley Department of Microbiology, Southern.IML Pathology, Wollongong, NSW, Australia Background: Francisella tularensis causes Tularaemia, a debilitating disease that typically presents as a non-specific acute febrile illness. It is a Security Sensitive Biological Agent (SSBA) and a Risk Group 3 organism. Case study: A left knee ganglion cyst aspiration fluid was received for culture. Primary cultures were negative and the cooked meat enrichment culture was turbid at 24 hours. Large, grey, irregular colonies were noted aerobically and anaerobically the next day from subculture. Gram stain revealed Gram-negative spore-forming bacilli. Spot tests indicated the bacterium was oxidase and catalase positive. MALDI-TOF MS identification failed. Biomerieux Vitek2 gave an identification of Francisella tularensis (99.9%). Further testing at a reference laboratory identified the possible F. tularensis isolate as Lysinibacillus massiliensis. Discussion: Both F. tularensis and L. massiliensis have nonreactive biopatterns, hence the use of commercial identification systems carries a high probability of misidentification. While the spot tests conducted in this case study did not indicate F. tularensis, and growth characteristics were not consistent with this as an identification, all potential SSBAs must be referred for further confirmatory tests. Transport of SSBA organisms requires triple-packaging and tracking at all steps in transit after reporting by phone. Possible implications for laboratory-acquired infection are discussed. RAPID ANTIGEN TESTS FOR POSITIVE COVID-19 CONFIRMATION IN THE LABORATORY SETTING Mikaela Dewar, Anica Pjevalica, Nicholas Clay, Brock Reitzer-Parks, Caitlin L. Keighley Department of Molecular Biology, Southern.IML Pathology, Wollongong, NSW, Australia; These authors contributed equally Introduction: Pooling patient samples for PCR testing increases throughput and has become standard practice during the COVID-19 pandemic. Accurate, rapid and cost-effective methods to determine the actual positive sample from a pooled well are needed. Aims: To determine the utility of rapid antigen tests for discerning the positive COVID-19 sample from pooled test results that are positive. Methods: 15 known positive and negative Covid-19 samples were tested using the Abbott Panbio COVID-19 Ag Rapid test device with a modified method suitable for use in the laboratory. Briefly, 150 mL of reaction buffer was mixed with 150 mL of patient sample from liquid swabs and the result was read at 15 minutes. Discussion: The performance of rapid antigen kits in this study were consistent with results using the standard method with direct inoculation of swabs. Samples yielding a Ct value below 25 were detected successfully, and those above that threshold failed. Thus for pooled positive results with a Ct value below 25, the current method can be used to discern the positive sample in that pool. This method would also lower the cost of further testing on pooled samples and expedite determination of the positive sample. Data collection is ongoing to further assess. Reference 1. Dinnes J, Deeks JJ, Berhane S, et al. Rapid, point-of-care antigen and molecular-based tests for diagnosis of SARSCoV-2 infection. Cochrane Database Syst Rev 2021; 3: CD013705. A CASE OF PROLONGED SARS-COV-2 VIRAL SHEDDING FOR 150 DAYS Andrew Fox-Lewis, Shivani Fox-Lewis, Sandra Hotu, Sally Roberts, Gary McAuliffe, Mary De Almeida 1Microbiology Department, Middlemore Hospital, Auckland, New Zealand; 2Microbiology Department, LabPLUS, Auckland City Hospital, Auckland, New Zealand; 3Respiratory Department, Auckland City Hospital, Auckland, New Zealand;