Conditions Affect Dust Mite Infestation Of Flour Samples In Tropical Area

Abstract

RationaleOral mite anaphylaxis is caused by ingestion of dust mite-contaminated flour in sensitized subjects. The type of flour, storage temperature and relative humidity influence mite propagation. The study aimed to investigate conditions affected the development of mite in order to provide appropriate flour storage instruction in a tropical country.MethodsDermatophagoides farinae(Der f) were inoculated in six types of cooking flour; two types of self-rising flour, plain wheat flour, tempura batter mix containing wheat flour, corn flour and tapioca starch. The samples were stored in different containers and kept in two conditions; at room temperature (mean temperature=26.6;range 25-28.9°C,mean relative humidity=69.6; range 60-77.3%) and in a refrigerator (mean temperature=8.2; range 2-12.2°C, mean relative humidity=36.7; range 22-51.4%) for 20 weeks. The analysis of Der f1 allergen levels was performed every 2 weeks by ELISA assay.ResultsDer f1 allergen levels at 6 weeks were significantly higher than baseline in both storage conditions regardless of container types(P<0.001). The maximum levels of Derf1 were found at 8 weeks. Comparing between the two storage conditions, room temperature storage enhanced growth of dust mites in all types of flour(P<0.001). Different types of flour had different influence on mite propagation. Self-rising flours yielded the highest numbers of mites followed by tempura batter mix containing wheat flour, plain wheat flour, corn flour and tapioca starch respectively (P<0.01).ConclusionsBoth storage conditions and types of flour affect dust mite infestation. In tropical regions, cooking flour should be kept refrigerate for no longer than 6 weeks in order to prevent significant mite propagation. RationaleOral mite anaphylaxis is caused by ingestion of dust mite-contaminated flour in sensitized subjects. The type of flour, storage temperature and relative humidity influence mite propagation. The study aimed to investigate conditions affected the development of mite in order to provide appropriate flour storage instruction in a tropical country. Oral mite anaphylaxis is caused by ingestion of dust mite-contaminated flour in sensitized subjects. The type of flour, storage temperature and relative humidity influence mite propagation. The study aimed to investigate conditions affected the development of mite in order to provide appropriate flour storage instruction in a tropical country. MethodsDermatophagoides farinae(Der f) were inoculated in six types of cooking flour; two types of self-rising flour, plain wheat flour, tempura batter mix containing wheat flour, corn flour and tapioca starch. The samples were stored in different containers and kept in two conditions; at room temperature (mean temperature=26.6;range 25-28.9°C,mean relative humidity=69.6; range 60-77.3%) and in a refrigerator (mean temperature=8.2; range 2-12.2°C, mean relative humidity=36.7; range 22-51.4%) for 20 weeks. The analysis of Der f1 allergen levels was performed every 2 weeks by ELISA assay. Dermatophagoides farinae(Der f) were inoculated in six types of cooking flour; two types of self-rising flour, plain wheat flour, tempura batter mix containing wheat flour, corn flour and tapioca starch. The samples were stored in different containers and kept in two conditions; at room temperature (mean temperature=26.6;range 25-28.9°C,mean relative humidity=69.6; range 60-77.3%) and in a refrigerator (mean temperature=8.2; range 2-12.2°C, mean relative humidity=36.7; range 22-51.4%) for 20 weeks. The analysis of Der f1 allergen levels was performed every 2 weeks by ELISA assay. ResultsDer f1 allergen levels at 6 weeks were significantly higher than baseline in both storage conditions regardless of container types(P<0.001). The maximum levels of Derf1 were found at 8 weeks. Comparing between the two storage conditions, room temperature storage enhanced growth of dust mites in all types of flour(P<0.001). Different types of flour had different influence on mite propagation. Self-rising flours yielded the highest numbers of mites followed by tempura batter mix containing wheat flour, plain wheat flour, corn flour and tapioca starch respectively (P<0.01). Der f1 allergen levels at 6 weeks were significantly higher than baseline in both storage conditions regardless of container types(P<0.001). The maximum levels of Derf1 were found at 8 weeks. Comparing between the two storage conditions, room temperature storage enhanced growth of dust mites in all types of flour(P<0.001). Different types of flour had different influence on mite propagation. Self-rising flours yielded the highest numbers of mites followed by tempura batter mix containing wheat flour, plain wheat flour, corn flour and tapioca starch respectively (P<0.01). ConclusionsBoth storage conditions and types of flour affect dust mite infestation. In tropical regions, cooking flour should be kept refrigerate for no longer than 6 weeks in order to prevent significant mite propagation. Both storage conditions and types of flour affect dust mite infestation. In tropical regions, cooking flour should be kept refrigerate for no longer than 6 weeks in order to prevent significant mite propagation.