Aerial fungal spectrum of Kolkata, India, along with their allergenic impact on the public health: a quantitative and qualitative evaluation

Airborne fungal spores are well documented to trigger respiratory allergy. The present study provides baseline information on the quantitative and qualitative aspects of aerospores for the first time in a typical urban area of Kolkata metropolis, India. An aeromonitoring was performed by Burkard volumetric 7-day sampler for two consecutive years (August 2012-July 2014). Total concentration, seasonal variations and intradiurnal periodicities of fungal spores were estimated. Spearman's rank correlation analysis was performed using various weather parameters. The prevalence of fungal spore allergy was investigated among patients reporting to the Department of Allergy and Asthma, Mediland Diagnostics, Kolkata. A retrospective review of patients was conducted with a standard questionnaire and performing skin prick test with 20 fungal extracts. Thirty-eight fungal genera were identified with the highest spore concentration in August. Relative humidity and rainfall were found to be positively correlated with spore concentration. A comparatively higher frequency of sufferers was observed for males and 15-35-year age group. Patients with an atopic family history and insidious onset of symptoms were prone to suffer more, and bronchial asthma was diagnosed in most. Out of 742 patients, 592 patients noticed to have positive skin reactivity toward one or more fungal extracts. Aspergillus fumigatus followed by Curvularia pallescens and Fusarium lateritium elicited maximum sensitization. Each of these genera also represented a considerable fraction of the total aeromycota, thereby indicating potential risk to the sensitized individuals. Further serological analysis along with the identification of fungal allergens would pave the way of immunotherapy.