German Cockroach Allergen Levels in North Carolina Schools: Comparison of Integrated Pest Management and Conventional Cockroach Control

Abstract

Cockroach suppression is fundamental to cockroach allergen mitigation in infested homes. The effects of various cockroach control strategies on cockroach populations and allergen concentration have not been examined in schools. This study was conducted to compare the effectiveness of integrated pest management (IPM) and conventional pest control in controlling German cockroach (Blattella germanica L.) infestations and concentrations of the cockroach allergen Bla g 1 in public school buildings. Two school districts included six schools that used conventional pest control and one district included seven schools that used IPM to control pests. Cockroach traps were deployed to assess the level of infestation, settled dust samples were collected in food service areas, classrooms, and other school areas, and the Bla g 1 allergen was quantified by ELISA. Both cockroach counts and Bla g 1 concentrations were dependent on the pest control approach, with highly significant differences between IPM-treated schools and conventionally treated schools in both the cockroach mean trap counts (0 versus 82.6 +/- 17.3 cockroaches/trap/wk, respectively) and in the amount of Bla g 1 in dust samples (2.8 +/- 0.3 versus 30.6 +/- 3.4 U/g dust). Cockroaches and Bla g 1 were primarily associated with food preparation and food service areas and much less with classrooms and offices. Our data extend recent findings from studies in homes, showing that cockroach allergens can be reduced by cockroach elimination alone or by integrating several tactics including education, cleaning, and pest control. IPM is not only effective at controlling cockroaches but also can lead to long-term reductions in cockroach allergen concentrations, resulting in a healthier environment for students and school personnel.

The Influence of Environmental Temperature and Humidity on Temporal Decomposition of Cockroach Allergens Bla g 1 and Bla g 2 in Feces

“…Our data clearly show a signiÞcant potential for the long-term persistence of cockroach allergens Bla g 1 and Bla g 2 under normal household temperature and humidity. This is, however, in strong contrast to the Þndings of many recent Þeld studies (Arbes et al 2004, Wang and Bennet 2009, Nalyanya et al 2009) that documented a signiÞcant allergen decline after cockroach extermination. We have to point out that in our experiments (i.e., both laboratory and household validation) the allergens were protected in feces inside opened plastic vials covered by the mesh.…”

“…Knowledge of the effect of various physical conditions or allergen management strategies (Eggleston and Arruda 2001, Nalyanya et al 2009) on cockroach allergens from indoor environment is important in designing more effective allergen mitigation programs. In this study, we observed the effect of temperature and moisture on the environmental fate of proteins and allergens in cockroach feces and, consequently, validated the laboratory model under Þeld conditions.…”

Environmental assessment and exposure reduction of cockroaches: A practice parameter

“…Not surprisingly, the number of cockroaches and levels of Bla g 1 were higher in food service areas than in classrooms and offices. 110 …”

Assessment of Environmental Cockroach Allergen Exposure

“…Two recent studies, one in schools and the other in homes, incorporated IPM principles as part of an allergen avoidance strategy. In an IPM study in North Carolina schools, Nalyanya et al [40]compared cockroach trap counts and cockroach allergen levels (Bla g 1) in 13 schools (6 which used conventional pesticide application and 7 which used IPM) [40]. During a single academic year, cockroach populations were monitored (using sticky traps) and dust was collected in classrooms where teachers had seen cockroaches or where the investigators' identified evidence of cockroaches.…”