Submitted to: International Conference on Urban Pests
Publication Type: Proceedings
Publication Acceptance Date: 7/1/1999
Publication Date: N/A
Citation: Interpretive Summary: Cockroach proteins (antigens) are the single most important allergen to asthmatic children. Management of cockroaches only reduces further production & accumulation of these potent allergens, but does not address the holistic need to mitigate both cockroaches & their proteins that contaminate the indoor environment. ARS scientists in Gainesville, FL, in cooperation with scientists from FDA, the EPA, Johns Hopkins Asthma & Allergy Center, & private sector pest management practitioners demonstrated new reduced-risk technologies in a 2-home pilot project in the homes of asthmatics in Baltimore, MD. "Precision targeting" software was used in conjunction with baited sticky traps to identify population centers of German cockroaches. Insects were then removed using a patented vacuum device, & a crack & crevice gel bait was applied to these locations. About 100 cockroaches were removed; 42 from the nightstand next to an asthmatic's sbed. A novel polyclonal cockroach antigen detection system was then used t "map" the distribution of antigens in the homes. A professional cleaning company cleaned one home, while the other was left uncleaned as the control. Post-cleaning sampling was conducted to determine the impact of the cleaning process that was performed without any prior experience or knowledge regarding cockroach allergens. Levels in the carpeted surfaces were reduced by about 80% while those on non-floor hard surfaces (counter tops, cabinets, etc.) often were unchanged or higher, suggesting that improper rinsing of cleaning rags redistributed the antigens. This study indicates that sustained management of pests & allergens is feasible, once standardized & documentable cleaning procedures are validated with this spatially-based precision targeting system.
Technical Abstract: Methods of assessing the presence of cockroaches & their attendant antigens in the environment are critical for the medical profession in evaluating asthma, and for the medical entomologist in developing & demonstrating reduced-risk management strategies. Previously, we developed & tested a polyclonal ELISA inhibition system for assessing spatial distribution of cockroach antigens (allergens) for subsequent mitigation interventions. In Baltimore, MD, the system was tested in homes of asthmatics to determine the impact of pest mitigation & professional cleaning on antigen load. Data were collected via pentablet using a customized hardware / software system (ArcView GIS) allowing spatial analysis. Data from sticky traps placed overnight showed German cockroaches in only one home where infestations were heaviest in upstairs bedrooms; about 100 cockroaches were removed including 42 from the nightstand next to an asthmatic's bed. Antigen levels sin the home without current infestation were below 150 cockroach-hr equivalents (c-h equiv), and no intervention was conducted. In the infested home, pre-cleaning antigen assays were as high as 2200 c-h equiv; 85% of the estimated antigen load was contained in less than 30% of the floor space, corresponding to areas where human exposure was probable. Post-cleaning sampling showed that levels in the carpet were reduced 80% while those on non-floor hard surfaces were variable, suggesting that improper rinsing of cleaning rags redistributed antigens. We conclude that this system allowed rigorous characterization of antigen loads, & that a standardized cleaning system could be developed & verified for efficacy.