Cockroach counts and house dust allergen concentrations after professional cockroach control and cleaning Rob McConnell, MD*; Craig Jones, MD†; Joel Milam, PhD*; Patty Gonzalez, RN†; Kiros Berhane, PhD*; Loran Clement, MD†; Jean Richardson, PhD*; Jean Hanley-Lopez, MD†; Kenneth Kwong, MD†; Najib Maalouf, MD†; Judith Galvan, MS*; and Tom Platts-Mills, MD‡ Background: It is known that cockroach allergen exposure is both frequent in inner-city homes and associated with asthma severity in children living in those homes. However, there have been few studies of interventions to reduce exposures in this setting. Objective: To evaluate the effect of short-term professional cockroach control and intensive cleaning on allergen concentrations. Methods: Families of children from a school-based asthma treatment program who had skin test results positive to cockroach allergen were enrolled if the home had cockroaches. Forty-nine homes were randomly assigned to receive professional cleaning with bait traps containing insecticide, professional cleaning with bait traps without insecticide, or no cleaning or bait traps. In all homes, dust was collected repeatedly to evaluate cockroach allergen Bla g 2 in the kitchen and bedroom, and cockroaches were trapped and counted repeatedly for more than 11 weeks. Results: Median cockroach counts were reduced in the homes treated with insecticide bait traps but not in other groups. There were significant reductions in allergen concentration in the kitchen in homes that received professional cleaning and had higher initial cockroach counts (54), regardless of whether bait traps had insecticide or not. Conclusions: We conclude that intensive cleaning can produce significant reductions in cockroach allergen in homes with heavy initial cockroach infestations. Ann Allergy Asthma Immunol. 2003;91:546–552. INTRODUCTION Studies have found asthma to be more severe in homes of children both allergic and exposed to indoor allergens, such as house dust mites or cockroaches, and it has been suggested that the increased severity of asthma found in inner-city children may be explained in part by exposures to cockroach allergens. 1 Low socioeconomic status has been associated with increased concentrations of cockroach allergen in house dust. In a recent study in southern New England, being African American or Hispanic, being of lower socioeconomic status, and living in multiple-family dwellings were shown to be associated with higher exposure to cockroach allergen and lower exposure to dust mite, cat, and dog allergen. 2 In studies of inner-city residents with asthma, up to 60% have been found to be allergic to cockroaches. 3 Therefore, cockroach allergen exposure is potentially an important public health problem in urban areas. Interventions to control house dust mite allergen have emphasized encasing bedding in allergen proof covers and washing sheets and bed covers in hot water (to kill dust mites and remove allergen). There is increasing evidence that such measures can successfully reduce allergen exposure and re- sult in improvements in clinical parameters of asthma, espe- cially bronchial responsiveness. 1,4 –7 However, there has been little study of the effect of interventions to control exposure to cockroach allergen in the homes of inner-city asthmatic children. Although professionally applied insecticides have rapidly reduced the number of live cockroaches, little reduc- tion in allergen occurred in house dust, in the absence of aggressive cleaning. 8 Even with professional cleaning, cock- roach allergen persisted at levels previously associated with increased asthma severity. 9 Previous studies that examined the effect of professional cockroach control have been limited by small sample size, lack of an appropriate control group, or by the fact that families were not selected contingent on a resident with allergy or asthma, conditions that might result in more motivated participants. In this study, we examined the feasibility of cockroach allergen reduction in inner-city Los Angeles homes with professional pest control and professional cleaning. A rela- tively larger sample of inner-city residences was recruited than in previous trials using professional cockroach control. Participating families had at least 1 child allergic to cock- * Department of Preventive Medicine, Keck School of Medicine at the University of Southern California, Los Angeles, California. † Department of Pediatrics, Keck School of Medicine at the University of Southern California, Los Angeles, California. ‡ Department of Pediatrics, University of Virginia, Charlottesville, Virginia. This study was supported by the National Institute of Environmental Health Sciences (grants 5 P01 ES09581 and 5 P30 ES07048), the Environmental Protection Agency (contract R 826708 – 01-0), the National Institute of Allergy and Immunology (grant R01AI020565), the Hastings Foundation, Southern California Particle Center and Supersite, and the Clorox Company. Received for publication November 8, 2002. Accepted for publication in revised form April 27, 2003. 546 ANNALS OF ALLERGY, ASTHMA, & IMMUNOLOGY