The Melbourne epidemic thunderstorm asthma event 2016: a 5-year longitudinal study

Area of Science:

• Environmental Health
• Respiratory Medicine
• Allergy Immunology

Background:

• The 2016 Melbourne epidemic thunderstorm asthma (ETSA) caused severe short-term asthma exacerbations.
• Long-term outcomes and effective interventions for ETSA survivors remain poorly understood.

Purpose of the Study:

• To assess the 5-year natural history of asthma symptoms in ETSA-affected individuals.
• To investigate the efficacy of grass pollen sublingual immunotherapy (Oralair) in improving asthma and allergic rhinitis control.

Main Methods:

• A single-centre prospective 5-year longitudinal study followed ETSA-affected individuals.
• An embedded open-label observational trial compared Oralair immunotherapy to a control group.
• Symptom severity, medication use, and adherence were assessed annually via questionnaires.

Main Results:

• Persistent asthma symptoms declined from 37% to 7% over 5 years, with few individuals remaining completely asymptomatic.
• Grass pollen allergen immunotherapy showed no significant difference in allergic rhinitis or asthma control compared to the control group.
• A subgroup receiving Oralair demonstrated improved asthma control between 2019 and 2021.

Conclusions:

• This study provides the longest follow-up of ETSA survivors, showing a gradual reduction but persistent asthma symptoms 5 years post-event.
• Oralair allergen immunotherapy did not offer significant additional benefits over standard care for asthma or allergic rhinitis in this cohort.
• The study period lacked subsequent ETSA events, precluding assessment of immunotherapy's protective effect against future episodes.