399 Daily Vacuum Cleaning Significantly Reduces House Dust Mite Allergen, Endotoxin and β-glucan Content of Mattresses

BACKGROUND: House dust mite allergic patients are advised to cover their mattresses with occlusive coverings; however, these are not cheap. We investigated whether daily vacuum cleaning of mattresses reduces house dust mite allergens, bacterial endotoxin and fungal β-glucan content. METHODS: Twenty volunteers vacuumed their mattress daily for 8 weeks. Dust samples, collected at two weekly intervals were analysed for house dust mite allergens (Der p 1 and Der f 1) by double monoclonal antibody ELISA and for endotoxin and β-glucan by the Limulus amoebocyte lysate kinetic assay. Data are presented as geometric means with 95% CI. RESULTS: Total house dust mite allergens (Der p 1 + Der f 1) significantly reduced from a geometric mean (95% CI) of 4.07 μg (2.44-6.79) at the start to 0.42 μg (0.21-0.81) at week 8. Total endotoxin and β-glucan were also significantly reduced from 13.6 EU (8.6-21.4) to 3.4 EU (2.3-5.0) and from 94.4 μg (57.1-156.2) to 19.7 μg (10.2-37.9) respectively (P for trend >0.0001). Percentage reductions in total house dust mite allergens, endotoxin and β-glucan after 8 weeks of daily vacuum cleaning were 85.1% (80.1-90.1), 71.0% (70.4-81.0) and 75.7% (70.4-81.0) respectively. This was mainly due to a 77.7% (70.8-84.7) reduction in total dust. CONCLUSIONS: Daily vacuum cleaning of mattresses over time significantly reduces house dust mite allergens, endotoxin and β-glucan. This gives house dust mite allergic patients a practical and cheap alternative to reduce their exposure to indoor bio-contaminants.