PREVENTION AND EXTERMINATION STRATEGIES FOR HOUSE DUST MITES AND THEIR ALLERGENS IN HOME TEXTILES

Abstract:
Preventing and exterminating clinically relevant concentrations of house dust mite allergen in the urban environment is one of the more interesting challenges for architects and building engineers, pest control contractors, cleaning services, and sanitary biologists. When this challenge is not met, up to 40% or more of the human population may be affected by allergic symptoms such as conjunctivitis, rhinitis, asthma or enema. The actual size of the problem in any given area depends on the massiveness and length of exposure to mite allergens arising from home textiles. Within Europe the sensitization rate for house dust mites ranges from 5% to 25% depending on the success of house dust mites (Pyroglyphidae) in dwellings. Yearly cost of allergy in the European Community amount to 9 milliard ECU, half of which is preventable by adequate avoidance measures. In ths report a strategy will be outlined that enables engineers, patients, doctors and nurses to take their part in preventing and clearing allergic symptoms caused by indoor factors. Starting from hygienic limits for allergen exposure, the different effective avoidance measures are systematized and discussed in the context of the technical or clinical discipline concerned. A step-wise approach is used for every patient: 1. Establishing sensitizations present; 2. Assessing actual exposure; and 3. Preparation and Execution of the Avoidance Plan. In low risk areas (such as Denmark) introducing only a higher level of ventilation proved successful in diminishng house dust mite allergen exposure to below clinically relevant levels. In high risk areas (such as the Netherlands) strategies advocated by the treating physician include cleaning, (re)furnishing and ventilation. Clinical results of general advice (handing out pamphlets) are presently so poor that drug treatment of patients has taken preference, and the source of the trouble (allergen exposure) is left untouched. There exists an increasing concern among family physicians, district nurses, economists as well as the general population. In these high-risk areas isolation and ventilation schemes should be combined with cleaning technologies fitting to the individual household. Parts of this extermination and prevention strategy were tested in (prospective) patient populations, showing a 50% or more reduction of clinical symptoms or disease.