Effects of aging and cleaning on bed bug (Hemiptera: Cimicidae)-derived histamine

Bed bugs (Cimex lectularius L.) are common indoor pests found in close association with humans. Bed bug feces have been identified as the primary source of indoor environmental histamine, an emerging contaminant that could pose a potential threat to human health. Therefore, it is critical that we understand the stability of histamine in homes, along with mitigation strategies so that we can reduce exposure and potential health risks. In this study we characterized histamine stability over time on 2 surfaces (unfinished wood, fabric), discovering that aging histamine at room temperature, over the course of 9 mo, showed no significant changes in the level of this biogenic amine. As histamine appears slow to degrade on its own, we evaluated the efficacy of various cleaning methods for reducing or removing histamine from these surfaces. The most effective histamine cleaning methods on fabric were bleach, hydrogen peroxide, and a laundry cycle, while multi-purpose cleaner, bleach, and hydrogen peroxide were the most effective on unfinished wood. Overall, histamine reduction was most influenced by more aggressive cleaning methods (hard scrubbing) or cleaners known for removing stains (hydrogen peroxide, bleach). The results of this study will enhance our ability to reduce exposure to this emerging contaminant.