AirborneAlternariaSpores: Potential Allergic Sensitizers in Saudi Arabia

Abstract

Background:In order to investigate the role of airborne Alternaria spp. in the sensitization of individuals having respiratory allergy symptoms, particularly bronchial asthma, an aerobiologic and clinical (diagnostic) study was conducted at several centers in Saudi Arabia. Materials and Methods: Airborne Alternaria spores were studied at four different centers in Riyadh, Jeddah and Al-Khobar, including three years at one site. Skin prick tests (SPT) were conducted on a total of 616 allergic individuals attending allergy clinics at six different hospitals in Abha, Qassim, Gizan, Jeddah, Hofuf and Makkah regions. Results: Alternaria spores constituted between 1.9%-9.6% of the total fungal air spora, and the maximum concentration exceeded 5x10 2 spores per m 3 of air in Jeddah, followed by 4.9x10 2 spores per m 3 in Al-Khobar. Mean weekly and monthly concentration of Alternaria fluctuated, reaching up to 150 spores per m 3 and 60 spores per m 3 , respectively. Quantitative regional variations were also recorded. IgE-mediated SPT reactivities conducted on allergic patients resulted in an overall 21.6% positive reactions, showing mild, moderate and strong wheal and erythema. Conclusion:The findings reveal that Alternaria spores are prevalent as a major component in the outdoor environment of the Kingdom, with peaks in April and October. The overall 21.6% positive SPT reactions indicate the sensitization level or cross-reactive sensitivity to Alternaria allergens. The study suggests that airborne Alternaria can be a potential allergic sensitizer in susceptible individuals and can be a risk factor in sensitized individuals with symptoms of bronchial asthma and allergic rhinitis in the Kingdom of Saudi Arabia.

Alternaria spores in the atmosphere of Sydney, Australia, and relationships with meteorological factors

“…Licorish et al (1985), however, suggest that of the order of 10 4 -10 7 spores need to be inhaled over a 24-h period. Hasnain et al (1998) suggest that a mean daily concentration of 50 Alternaria spores/m 3 are needed to cause sensitisation, after which smaller concentrations can cause symptoms.…”

The influence of meteorological parameters on Alternaria and Cladosporium fungal spore concentrations in Beja (Southern Portugal): preliminary results

“…Ianovici et al (2013) cites Targonsky et al (1995), who described the atmospheric concentration of 2000 spores/m 3 as linear to Cladosporium spores, cause clinical symptoms. With regard to Alternaria spores, Ianovici et al (2013) cites Hasnain et al (1998), who suggested that clinical symptoms occur with atmospheric concentrations higher than 50 spores/m 3 .…”

Dynamics (seasonal and intra-diurnal) of air-borne fungal spore population of Doha area, Qatar

“…Fungal spores, due to their volume in the atmosphere and small size, have an important contribution to the respiratory allergies and cause various symptoms range from asthma, allergic rhinitis to bronchitis (Vijay et al1991, D'amato &Spieksma 1995, Hasnain et al, 1998. It has been demonstrated that the environmental factors such as meteorological and seasonal climatic factors Klarić & Pepeljnjak, 2006), the type of vegetation (Pepeljnjak & Šegvić, 2003), air pollution (Lin &Li, 2000), and human activities , affect the variety of air borne fungi.…”