P176 Investigating environmental factors associated with cerebral abscesses in patients with pulmonary arteriovenous malformations via an international online questionnaire

Introduction and objectives Patients with pulmonary arteriovenous malformations (PAVMs) are at high risk of cerebral abscess with life-changing morbidity and mortality. These patients often concurrently have hereditary haemorrhagic telangiectasia (HHT). A recent study of patients with PAVMs/HHT at a single institution suggested several environmental associations with cerebral abscess, particularly dental care, higher iron intake, and long-haul flights.1 For example, 4/37 (10.8%) cerebral abscess patients reported their abscess occurred after long-distance travel. Methods In order to capture data on wider exposure of this population to such risk factors, an online questionnaire was developed using Survey Monkey. In total, 139 non-biassed questions gathered data online about an individual’s HHT and/or PAVM phenotype, and environmental factors of relevance to cerebral abscess and other study foci in our group. With ethical approval (16/LO/1909), participants were recruited following advertisement through global HHT support networks. Results The survey opened on 31 st May 2017. Within 7 weeks, 449 patients with self-reported HHT had completed the questionnaire. The majority (≥60%) were North Americans, with Europeans constituting the second largest group. 229 (51%) had PAVMs, usually diagnosed in their twenties to fifties. 89/229 (38.9%) had been treated by PAVM embolization and 13 (5.7%) by surgery. 17 (7.42%) had experienced a cerebral abscess and 46 gave a family history of cerebral abscess. Preliminary analysis of long-distance travel data revealed most patients rarely travelled for ≥3 hours. 266 participants reported the number of flights they had taken in their lifetime of durations Conclusions This survey provides a large dataset from individuals with PAVMs/HHT, captured without a bias toward flight usage as in flight-specific surveys. The data suggest long-distance travel is less common than previously thought for the HHT population, which adds greater weight to the previously published association[1] between long-distance travel and cerebral abscess risk. This approach should enable the development of better tools to predict and reduce the risk of cerebral abscess for these patients. Reference Bootheret al. Clin Infect Dis2017, Apr 19. doi:10.1093/cid/cix373