ABSTRACT
Six apartments in a low-income housing project were evaluated for German cockroach. Blattella germanica (L.), infestation and concentration of an allergen derived from these cockroaches (Bla g II). Kitchen and living room samples were collected monthly for 1 yr. In addition, airborne sampling was carried out in 5 kitchens. The kitchen had the highest allergen concentration in 65% of visits and the highest number of cockroaches trapped in 69% of visits. In the kitchen, the highest cockroach levels were seen in June, whereas the values for Bla g II peaked in August. In keeping with this, the closest correlation was between Bla g II (microgram/g dust) and the number of cockroaches found 2 mo earlier. Airborne samples were assayed for 2 separate allergens. Bla g II and Bla g I. No allergen was detectable in the absence of disturbance. By contrast, during disturbance with a vacuum cleaner both Bla g II and Bla g I were detectable in the air of each apartment. Results suggest that immunochemical assay of a major allergen in dust samples from the kitchen floor may be used to monitor exposure to German cockroaches, also that cockroach levels may be used as an indicator or predictor of allergen in dust.
Subject(s)
Allergens , Cockroaches , Animals , Evaluation Studies as Topic , Humans , Poverty , SeasonsABSTRACT
American house dust mites, Dermatophagoides farinae Hughes, were marked by adding a 4% solution of Sudan Red 7B, a microbiological stain, to mite rearing media. Marked mites were released onto a downstairs couch in a 2-story residence. Two children sat on the couch for approximately 3 h after which their clothes were examined for stained mites. Various parts of the house and family vehicle were vacuum sampled, and dust samples examined for presence of marked mites. Results of 2 trials showed the presence of marked mites on clothing, upstairs in the residence, as well as in the family vehicle. Clothing is shown to be a significant factor in the dispersal of American house dust mites. Even if concentrated in a small area (1 couch), mites were able to disperse throughout the house and into a family vehicle within a matter of weeks.
Subject(s)
Mites , Residence Characteristics , Animals , HumansABSTRACT
Three bioassay techniques for testing pesticides against the American house dust mite, Dermatophagoides farinae Hughes, and the European house dust mite, Dermatophagoides pteronyssinus (Trouessart), were evaluated using cypermethrin as a standard. All 3 bioassay techniques gave linear responses, and can be used for evaluation of different properties of compounds. The slide dip technique tests for contact activity, the plastic petri dish technique for residual activity on a nonporous surface, and the fabric technique for residual activity on a porous surface. The 2 species of house dust mites responded similarly to all 3 bioassays, indicating that these 2 species are equally susceptible to cypermethrin under a variety of test conditions. In further tests with the fabric technique, the composition of the fabrics used did not significantly affect the toxicity of the compound tested.
