BACKGROUND: On 21st November 2016, Melbourne experienced an epidemic of ‘thunderstorm asthma.’ Although previously described in the literature, risk factors and natural history remain incompletely understood. OBJECTIVE: Our aim was to follow up those presenting to the 3 Emergency Departments (EDs) in our health service during the epidemic, and assess their history for previous asthma, rhinitis, and allergies. METHODS: ED notes of all respiratory presentations within 48 hours of the thunderstorm event were reviewed and patients with acute asthma included. A standardised questionnaire was devised encompassing asthma diagnosis, undiagnosed asthma symptoms and rhinitis severity. Patients were contacted by phone within 30 days of the event. RESULTS: Three hundred forty-four patients were identified overall; 263 patients were contactable and completed a phone or mail questionnaire. The mean age was 32.7 ± 19.2 years (range, 6 months–87 years; 25% < 18 years) with 58% male sex. A previous diagnosis of asthma was present in 42% (n = 111), and there was no previous asthma diagnosis in 58% (n = 152). Of those who had no asthma diagnosis 53% had probable undiagnosed asthma. Overall, rhinitis prevalence was 88%, of which 72% were moderate or severe (Allergic Rhinitis and its Impact on Asthma guidelines) and 51% (n = 133) reported a history of grass pollen allergy. CONCLUSION: Our data highlights the importance of atopy and rhinitis as risk factors for epidemic thunderstorm asthma. Better identification of undiagnosed asthma, and implementing treatment of asthma and rhinitis may be important.
Asthma ; Diagnosis ; Emergency Service, Hospital ; Follow-Up Studies ; Health Services ; Humans ; Hypersensitivity ; Male ; Natural History ; Poaceae ; Postal Service ; Prevalence ; Rhinitis ; Rhinitis, Allergic, Seasonal ; Risk Factors

Scrapie is diagnosed antemortem in sheep by detecting misfolded isoforms of prion protein (PrP(Sc)) in lymphoid follicles of the rectal mucosa and nictitating membranes. Assay sensitivity is limited if (a) the biopsy is collected early during disease development, (b) an insufficient number of follicles is collected, or (c) peripheral accumulation of PrP(Sc) is reduced or delayed. A blood test would be convenient for mass live animal scrapie testing. Currently approved techniques, however, have their own detection limits. Novel detection methods may soon offer a non-animal-based, rapid platform with detection sensitivities that rival the prion bioassay. In anticipation, we sought to determine if diseased animals could be routinely identified with a bioassay using B lymphocytes isolated from blood sample volumes commonly collected for diagnostic purposes in small ruminants. Scrapie transmission was detected in five of six recipient lambs intravenously transfused with B lymphocytes isolated from 5~10 mL of blood from a naturally scrapie-infected sheep. Additionally, scrapie transmission was observed in 18 ovinized transgenic Tg338 mice intracerebrally inoculated with B lymphocytes isolated from 5~10 mL of blood from two naturally scrapie-infected sheep. Based on our findings, we anticipate that these blood sample volumes should be of diagnostic value.
Animals ; B-Lymphocytes/*pathology ; Biological Assay/*veterinary ; Mice ; Mice, Transgenic ; Prions/*blood ; Scrapie/blood/*diagnosis/transmission ; Sheep