471 - Rats in the city: A look at rat allergen testing and sensitization in kids with asthma Rats in the city: A look at rat allergen testing and sensitization in kids with asthma

Publication Number: 471.6228

Marieke H. Rosenbaum, Tufts University Cummings School of Veterinary Medicine, North Grafton, MA, United States; Diane Story, Boston Children's Hospital, Boston, MA, United States; Joseph Wilson, Harvard University, Cambridge, MA, United States; Shikhar Shrestha, Tufts University School of Medicine, Boston, MA, United States; Shalini Shah, Boston Children's Hospital, Boston, MA, United States; Faye Holder-Niles, Boston Children's Hospital, Boston, MA, United States; Wanda Phipatanakul, Boston Children's Hospital, Hopkinton, MA, United States; Marissa Hauptman, Boston Children's Hospital, Boston, MA, United States

Background: Pediatric asthma is an environmentally-mediated disease that disproportionately impacts urban Black and Latino children. While several studies have demonstrated that sensitization rates to mouse and rat allergens are similar among asthmatic children, comparatively little research exists on rat exposure and associations with asthma morbidity despite evidence that urban rat populations are increasing worldwide.

Objective: Assess rat allergen testing, sensitization, asthma control, and relative rat exposure among children with asthma living in a major US city.

Design/Methods: Patient data were obtained from records of primary care patients at Boston Children’s Hospital. Patients’ demographic information, lifetime specific IgE levels, and lifetime Asthma Control Test (ACT) results were also collected and analyzed with descriptive statistics and chi-square analyses. The publicly available City of Boston rat-associated 311 call database is being used to determine relative rat abundance around the participant’s home, and associations between rat sensitization, asthma morbidity, and relative rat abundance near the home will be examined using geospatial analysis.

Results: 5560 patients were included in the BCH Asthma Registry (mean age 12.73 years, 56.8% male). 4163 patients (83.0%) completed the ACT, of which 2674 (58%) had at least 1 ACT score less than or equal to 19, indicating poorly controlled asthma. 650 (11.7%) patients were tested for any allergen, of which 349 (53.7%) tested positive. 58 patients (1.0%) were tested for rat allergen sensitization, of which 19 (32.8%) were positive. 484 patients (8.2%) were tested for mouse allergen sensitization, of which 206 (42.6%) were positive. The likelihood of having at least one ACT less than or equal to 19 differed significantly from the study population among those who tested positive for rat allergen (73.7%, p=.035), those who tested positive for mouse allergen (69.8%, p<.001), and those who tested positive for any allergen (74.8%, p<.001).

Conclusion(s): We observed similar rates of rat and mouse sensitization among children with asthma, and similar rates of asthma control associated with rat and mouse sensitization. However, testing rates for rat allergen sensitization are much lower than for mouse. Integrating relative rat exposure using the rat-associated 311 complaint call database into the analysis is ongoing. These data suggest that rat exposure may be an under-recognized and understudied trigger for asthma exacerbation among urban children and further research is warranted.