title: Association of airborne Aspergillus with asthma exacerbation in Southern Pakistan.
abstract: BACKGROUND
  Exposure to airborne fungi has been related with exacerbation of asthma in adults and children leading to increased outpatient, emergency room visits, and hospitalizations. Hypersensitivity to these airborne fungi may be an important initial predisposing factor in the development and exacerbation of asthma.
  
  
  OBJECTIVE
  This study was conducted to determine an association between fungal types and spore concentrations with the risk of asthma exacerbation in adults.
  
  
  METHODS
  This cross-sectional study was conducted from May 2008 to August 2009 at the Aga Khan University Hospital Karachi, Pakistan. All adult (age≥16 years) patients presenting to the hospital with acute asthma exacerbation were enrolled after informed consent. A home survey was conducted for each patient to assess their environmental characteristics. Indoor air samples were also obtained from the patient's home to determine the type and spore concentration of fungi within the week of their enrollment in the study.
  
  
  RESULTS
  Three hundred and ninety-one patients with an acute asthma exacerbation were enrolled during the study period. The mean age of participants was 46 years (standard deviation, ±18 years) and 247 (63.2%) were females. A trend of higher asthma enrollment associated with higher Aspergillus concentrations was found in two consecutive summers. A total of nineteen types of fungi were found in air samples. Aspergillus spp. was the most frequently isolated fungus with acute asthma exacerbation.
  
  
  CONCLUSIONS
  An association of higher concentration of indoor Aspergillus spp. with asthma exacerbation in adults was observed in this study.
authors.affiliation: Department of Medicine, Aga Khan University, Karachi 74800, Pakistan.
authors.forename: Ali Bin Sarwar
authors.initials: AB
authors.lastname: Zubairi
authors.affiliation: Department of Community Health Sciences, Aga Khan University, Karachi 74800, Pakistan.
authors.forename: Iqbal
authors.initials: I
authors.lastname: Azam
authors.affiliation: Department of Medicine, Aga Khan University, Karachi 74800, Pakistan.
authors.forename: Safia
authors.initials: S
authors.lastname: Awan
authors.affiliation: Department of Pathology and Microbiology, Aga Khan University, Karachi 74800, Pakistan.
authors.forename: Afia
authors.initials: A
authors.lastname: Zafar
authors.affiliation: Department of Medicine, Aga Khan University, Karachi 74800, Pakistan.
authors.forename: Asif Ali
authors.initials: AA
authors.lastname: Imam
keywords: Aspergillus; Asthma; Fungal spores; Pakistan