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Airborne fungi infections. Dr David W. Denning FRCP FRCPath Scientific Advisor to the Fungal Research Trust Clinician, Wythenshawe Hospital Head, Antifungal Testing Laboratory Faculty, University of Manchester WWW.aspergillus.man.ac.uk. Airborne fungal infections.
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Airborne fungi infections Dr David W. Denning FRCP FRCPath Scientific Advisor to the Fungal Research Trust Clinician, Wythenshawe Hospital Head, Antifungal Testing Laboratory Faculty, University of Manchester WWW.aspergillus.man.ac.uk
Airborne fungal infections Fungi are all around us in the air and yeasts (ie Candida) live in our guts Exposure to fungi is one of life’s certainties
Aspergillus – 38 species have caused disease Common in the environment Aspergillus fumigatus Aspergillus niger www.aspergillus.man.ac.uk
Aspergillus spore head Spores 3uM across (i.e. easily are drawn into the lungs)
The supporting cast Alternaria Cladosporium Penicillium
Airborne fungi and their ‘diseases’ Invasive (life- threatening) infection Chronic infection Allergy/asthma Aspergillus Alternaria Cladosporium Penicillium Others
Where are airborne fungi found? Outside air Home Hospital
Airborne fungi and pillows Feather pillow Synthetic pillow
Fungus in the bedroom We have been examining pillows for fungi: *Other common species were other Aspergillus spp., Penicillium spp., Cladosporium spp. What this means is that each ‘old’ pillow contains ~1 million fungal spores Woodcock et al, Allergy 2005 In press
Airborne fungi Common sources of airborne fungi Outside air – especially Cladosporium After thunderstorms – esp Alternaria In homes – esp Aspergillus and outdoor fungi In hospitals – esp Aspergillus
Airborne fungi on air conditioning systems in hospital (intake ducts)
Airborne fungi in hospital Outside room Inside room
Airborne fungi in hospital after continous air filtration Outside room Inside room
Invasive aspergillosis Chronic pulmonary aspergillosis Allergic aspergillosis ABPA Severe asthma association
Invasive aspergillosis Chronic pulmonary aspergillosis Allergic aspergillosis ABPA Severe asthma association
Life-threatening aspergillosis 24 year old with genetic immune defect
Predicted numbers ofinvasive Aspergillus infections in the UK Actual cases ? ? ? ? ? ? ? ?
Invasive aspergillosis Chronic pulmonary aspergillosis Allergic aspergillosis ABPA Severe asthma association
Chronic pulmonary aspergillosis January 2001 30 year old smoker with no immune defect
Chronic pulmonary aspergillosis April 2003 30 year old smoker with no immune defect
Predicted numbers ofchronic lung Aspergillus infections in the UK Those at risk Prior TB (?5%) Sarcoidosis with cavitation (12% of all) Lung damage (pneumothorax etc) Prevalence rate in the UK ???? 200-1000 cases Incurable currently (require life-long treatment)
Invasive aspergillosis Chronic pulmonary aspergillosis Allergic aspergillosis ABPA Severe asthma association
ABPA Plug in airways Airway clear after removal
ABPA with airway obstruction Mild asthma with shortness of breath
Predicted numbers ofABPA patients in the UK Those at risk Adults with asthma = 4,100,000 on treatment Cystic fibrosis = 2,700 adults Prevalence rate in the UK ~ 1% of asthmatics = 41,000 patients ~15% adult CF patients = 405 patients
Invasive aspergillosis Chronic pulmonary aspergillosis Allergic aspergillosis ABPA Severe asthma association
Aspergillus fumigatus Alternaria Cladosporium Candida Penicillium Negative Control Grass Histamine House dust mite Cat Dog
Spore counts and asthma attacks and admission to hospital • All circumstantial evidence • Thunderstorm asthma – linked to Alternaria • Asthma deaths (Chicago) linked to high ambient spores counts and season (summer autumn) when spore counts highest • Asthma hospital admission linked to high ambient spore counts (Derby, New Orleans, Ottawa) • Asthma hospital attendance linked to high spore counts, but not pollen counts (Canada) • Asthma symptoms increased on days of high spore counts (California, Pennsylvania)
Fungus at home • Environmental data • Mouldy housing associated with worse asthma • Wheezing in children associated with damp housing • Mouldy and damp school associated with asthma symptoms and emergency room visits • Highest concentration of Aspergillus fumigatus is at home
Airborne fungal fragments Fungal fragment Diffusing allergen leeching out of fungus in contact with liquid
Hospital admission with asthmatic attacks and mould allergy Allergen Asthma, no admission (n=82) Asthma, 2+ admission (n=46) House dust mite 56 % 67 % Grass pollen 46 % 63 % Cat 37 % 59 % Dog 18 % 48 % Any non fungal allergen 70% 74% O’Driscoll et al, BMC Pulm Med 2005;18:4
Hospital admission with asthmatic attacks and mould allergy Allergen Asthma, no admission (n=82) Asthma, 2+ admission (n=46) Aspergillus 7 % 37 % Alternaria 5 % 26 % Cladosporium 1 % 41 % Penicillium 2 % 30 % Candida 10 % 33 % Any fungal allergen 16% 76% O’Driscoll et al, BMC Pulm Med 2005;18:4
Severe asthma and moulds Severe asthma – 235 (21%) of all asthmatics Odds ratio Increasing frequency of fungal skin test positivity in severe asthma Zureik et al, Br Med J 2002;325:411
Predicted numbers ofsevere asthmatics with fungal sensitisation in the UK Those at risk Adults with asthma = 4,100,000 on treatment Severe asthma = 5-21% Mould allergic = 35-50% Prevalence rate in the UK Lower number = 71,750 patients Upper number = 430,500 patients ~40,000 adults admitted to hospital in the UK each year with asthma Admissions reduced to 25% with antifungal therapy in 14 patients (pre antifungal - 1.63 admissions per year, post antifungal 0.4)
Conclusions Fungi are all around us in the air Exposure to airborne fungi is one of life’s certainties Many people in the UK have infection or allergy due to fungi, and additional research and care is required for these patients. Ascertainment of national caseload would be useful