Prevalence of airborne Aspergillus flavus in Khartoum (Sudan) airspora with reference to dusty weather and inoculum survival in simulated summer conditions.

Khartoum air was scanned for airborne Aspergillus flavus for 12 months using the horizontal gravitational settling method. Frequency of occurrence was related to total fungal catch and dusty weather. The Aspergilli were prevalent (68% of total isolated/plate/month) and A. flavus constituted 31% of the total Aspergilli. In June (hot, dry & dusty) Aspergilli constituted 79% of the total isolates, whilst A. flavus represented 30% from amongst the other Aspergilli. A. flavus, A. niger, A. nidulans (conidial & ascosporic states), A. terreus, Eurotium amstelodami and A. fumigatus, in descending order of prevalence were isolated in June. Other pathogenic or potentially pathogenic forms, isolated, were Cladosporium, Curvularia and Penicillium. Amongst winter isolations A. flavus was sporadic to absent in occurrence. A. flavus spore inocula that underwent hourly intermitted exposure to 45 degrees C, showed a decrease in spore germinability as well as reduced germ length.