German cockroach (Blattella germanica)
New research compared the levels of endotoxins in the air in homes with cockroach infestations before and after disinfestation and found that there is a strong link between the presence of the animals and the allergens.
A new published in the Journal of Allergy and Clinical Immunology: Global confirmed that there is a strong link between cockroach infestations and harmful allergen levels and bacterial toxins found indoors.
Research shows that when infestations are successfully eliminated, allergen and endotoxin levels drop dramatically, improving indoor air quality and potentially reducing respiratory health risks.
Endotoxins are fragments of bacterial cell walls released when bacteria die. Because cockroaches feed on a wide variety of materials, their digestive systems harbor diverse bacteria which release large amounts of endotoxins in their feces. Although humans and pets also contribute to the presence of endotoxins in indoor environments, the study found that a significant portion originates from cockroach feces, explains the .
“Endotoxins are important for human health, as inhalation of these components has been shown to cause allergic reactions”, said Coby Schal, professor of Entomology at North Carolina State University and co-author of the study.
The team conducted the study at apartment complexes in Raleigh, measuring cockroach infestations along with concentrations of suspended and airborne dust before and after pest control interventions. The results revealed that units with high infestation contained significantly higher concentrations of endotoxins, with female cockroaches producing around double the amount produced by males due to greater food intake. The researchers found that kitchens tended to harbor more endotoxins than bedrooms.
To test the impact of pest control, the infested apartments were divided into two groups: one received professional pest control, while the other received no treatment. A third group of homes without cockroach problems served as controls. After three and six months, the houses that were subjected to rat control showed substantial reductions both in allergens and endotoxins, while untreated homes remained contaminated.
“By eliminating cockroaches, you eliminate the allergens they produce,” explained Schal. “Endotoxins decreased significantly in homes where cockroaches were eliminated. This demonstrates that the cockroach is the main depositor of endotoxins in infested houses.”
