The control of house dust mites in rugs through wet cleaning

Nine rugs from the bedrooms of seven private homes were cut into strips. Half of the strips were wet-cleaned according to a commercial procedure, and the others were kept as controls. Subsequently the cleaned and noncleaned strips were stitched together again and returned to their respective bedrooms. After 0, 1, and 3 months, parts of the strips were taken to the laboratory for tests. The tests were designed to measure the suitability of the rugs as a habitat for house dust mites. To do this, a number of house dust mites were introduced into fragments of the rugs, and the number of survivors and offspring after 4 weeks was determined. Immediately after cleaning, the habitat was markedly less suitable than before. After 1 month, the habitat suitability was partly but not totally recovered. After 3 months, no effect of cleaning could be discerned.