P109 When is Burkholderia cepacia complex truly eradicated in adults with cystic fibrosis? a 20-year follow up study

<h3>Introduction and Objectives</h3> Due to increased morbidity associated with <i>Burkholderia cepacia</i> complex (BCC) infection in cystic fibrosis (CF), it is recommended that patients are segregated to prevent cross-infection. To date there are no evidence-based eradication treatment regimens and there is no universally agreed consensus on the number of negative samples required or the time interval since last isolation of BCC for eradication to be deemed successful. Our objectives were to determine the duration after which it is likely that BCC has been eradicated or cleared, and where BCC was eradicated any significant differences in treatment duration or modality. <h3>Methods</h3> All cases of new BCC isolation at a large adult CF centre were followed up between May 2002 and May 2022. The number of subsequent positive and negative sputum samples for BCC were recorded, as well as details of eradication treatment received. Cases of BCC isolation were deemed to have been successfully eradicated if there were ≥3 negative sputum samples and no further positive sputum samples for the same species and strain over ≥12 months until the end of follow-up. <h3>Results</h3> Of 50 new BCC isolations, 28 were successfully eradicated and 22 resulted in chronic colonisation. 6 (18.2%) cases with exclusively negative sputum samples 6–12 months after initial isolation subsequently re-isolated BCC and 3 (10%) cases with exclusively negative sputum samples after 12–24 months re-isolated BCC. There were no significant differences in eradication treatment duration, number of antibiotics or administration route between cases of BCC which successfully eradicated versus those which resulted in colonisation. <h3>Conclusions</h3> A cautious approach to segregation should be maintained after new isolation of BCC in CF, as some individuals with ≥3 negative sputum samples 12–24 months after initial isolation subsequently re-isolated BCC. Randomisation controlled trials are needed to guide treatment strategies for eradication.