Prevalence of airborne allergenic Amaranthus viridis pollen in seven different regions of Saudi Arabia

Amaranthus pollen grains are known to be highly allergenic and a potential cause of respiratory allergic diseases. Nevertheless, data on the prevalence of Amaranthus pollen in the environment is limited and almost non-existent for Saudi Arabia. We conducted an investigation to record the airborne incidence of A. viridis and other allergenic pollen in Al-Khobar, Dammam, Hail, Jeddah, Jizan, Qassim and Taif, using Burkard Volumetric Samplers. The samplers were operated continuously for one year at each location. The data revealed A. viridis as one of the major components of outdoor airspora, constituting a maximum of 96% of total pollen counts in Hail, followed by Al-Khobar [89%], Jeddah [87%], Qassim [85%], Taif [84%], Dammam [83%] and Jizan [61%]. These higher percentages contributed largely to the total weed pollen catch during August to November in all seven regions. In addition, the data also showed that A. viridis pollen were present throughout the year with distinct seasonal variations. The diel periodicities for at least five sites averaged over a year showed mid-day to early evening maxima. The maximum concentration approached 3000/m[3] of air in October and 1827/m[3] of air in September. The data also exhibited a seasonal pattern in their maximum appearance. Further studies related to biochemical and allergological aspects are needed to confirm the allergenic impact of Amaranthus pollen and sensitization in allergic individuals in the Kingdom of Saudi Arabia

Airborne alternaria spores: potential allergic sensitizers in Saudi Arabia

In order to investigate the role of airborne Aternaria 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. 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. Alternaria spores constituted between 1.9%-9.6% of the total fungal air spora, and the maximum concentration exceeded 5xl0[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 Aternaria 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. 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 Aternaria allergens. The study suggests that airborne Aternaria 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

Cladosporium as an airborne allergen in Saudi Arabia

Airborne mold monitoring in three cities in Saudi Arabia has documented the presence of Cladosporium in high concentrations. The spore counts reached threshold levels for sensitization at Jeddah and Al-Khobar with prominent seasonal variations. The concentration in Riyadh [central region] showed levels with minor fluctuations and a minor peak towards the month of November. Indoor monitoring also revealed the presence of Cladosporium. Ten species of Cladosporium were identified with C. sphaerospermum, C. herbarum, C. cladosporoides and C. macrocarpum being most prevalent. The species are relevant in relation to extracts for diagnosis. Skin testing of asthmatic children in Riyadh and Makkah revealed reactivities to Cladosporium extract of 5.8% and 31.3%, respectively. This indicates that Cladosporium may be an important allergen in the region that necessitates further biochemical and immunochemical studies to confirm the allergenic impact of the species of Cladosporium prevalent in the region

Seasonal periodicities of fungal allergens in the atmosphere of Riyadh

Aerobiological studies to evaluate allergenic fungal spores in the atmosphere of Riyadh were conducted using Burkard volumetric 7-day recording spore trap and culture plate techniques from November 1986 through October 1987. Thirty-two generic and morphologic categories were recorded. The majority of these fungal spores belonged to dry-air spore of conidial fungi, originating from garbage, rubbish bins, stored fruits and vegetables, and the like. Cladosporium spp. Constituted 24.8% [mean value] of total air spora over the 12-month period, ranging monthly from 8.5% to 40%; smuts [Ustilago and other species] 13.4% [range, 1.6% to 25.6%]; Alternaria spp. 5.6%[range, 1.9% to 9.6%]; Ulocladium spp. 3.4% [range, 1.0% to 6.8%]; Chaetmium 1.8% [range, 0.7 to 4.2%]; Drechslera and Helminthosporium 1.8% [range, 0 to 5.4%]. Basidiospores constituted 3.1% [rage, 1.5% to 5.7%]. Peak hourly concentrations for all categories were recorded, Cladosporium having the highest concentration. Seasonal periodicities showed an increase in concentration in the warmer months and a decline in the winter