An evaluation of the efficacy of domestic allergen-avoidance: Using vacuum cleaners with high-efficiency exhaust filtration to reduce fungal exposure and impermeable bedding encasements to reduce dust -mite exposure

Allergen avoidance is an important component in the treatment of allergic diseases. The objective of this study is to evaluate the effectiveness of two specific methods of allergen avoidance in reducing exposures to indoor aero-allergens. The efficacy of long-term use of vacuum cleaners with high-efficiency exhaust filtration to reduce residential fungal-spore exposure was assessed in a field study. The efficacy of using impermeable bedding encasements to reduce dust-mite allergen exposures and improving lung function in asthma patients was assessed in a review and meta-analysis of published data.;The use of vacuum cleaners with high-efficiency exhaust filtration did not have an effect on most airborne fungal levels in homes during the study. Airborne concentrations of fungi whose main sources are outdoors were unrelated to the type of vacuum-cleaner exhaust filtration. Some types of fungi that may have substantial indoor sources were present in somewhat lower levels during the heating season in homes using high-efficiency vacuum cleaners. This may indicate that high-efficiency vacuums can reduce indoor fungal reservoirs and could have some benefit in reducing indoor exposures in homes where the influence of outdoor airborne fungal spores is minimized by limiting outdoor air intrusion.;The effectiveness of bedding encasement in clinical trials of dust-mite allergen avoidance varied substantially among studies, with effective reduction in exposure and concomitant improvement in lung function demonstrated in a few studies. However, the majority of studies analyzed found either little reduction in allergen exposure or little improvement in lung function even when dust-mite allergen exposure was decreased. A formal regression analysis showed that bedding encasement appeared to be most effective under conditions where initial allergen exposure levels were high and exposure levels were reduced below levels reported to be associated with asthma morbidity.;The dissertation makes public-health recommendations regarding the use of these allergen-avoidance methods as part of asthma interventions. Recommendations are also made for additional studies that might help to further clarify the role of domestic allergen-avoidance in the public-health and clinical responses to allergic diseases.