by Elizabeth Matsui
Mice are responsible for many asthma exacerbations, including emergency department visits and hospitalizations, among children in Baltimore and other cities. There is mouse allergen, the protein produced by mice that triggers allergic symptoms, in virtually every home in low-income neighborhoods in Baltimore, and it has been this way for many years. In fact, we find mouse allergen in the air in 80-90% of the bedrooms of children with asthma, and in about 1 of every 4 of these bedrooms, the amount of mouse allergen in the air is similar to what is measured in research facilities that contain many cages full of mice. We also know that a little over half of the children coming to the emergency room for asthma are allergic to mice. This combination – that most children with significant asthma are allergic to mice and all of these children are living in homes with mouse allergen, inhaling mouse allergen into their lungs while they sleep - is a set up for a major public health problem. So it should come as no surprise that rates of visits to the emergency room and hospitalizations for asthma among children in Baltimore are 2-3 times higher than in Maryland. And when these children are discharged, they go back to their homes, where they resume inhaling mouse allergen. Because the problem is so common and appears to be insoluble, asthma attacks, and emergency department visits and hospitalizations for asthma are just a part of life because they have become woven into the fabric of the community.
Although these statistics are specific to Baltimore, this same paradigm is true in other low-income communities in the US. Many of these communities also have terrible problems with endemic mouse infestation, but there are also other indoor exposures that are responsible for asthma attacks, including cockroach allergen, second hand smoke exposure, and other indoor pollutants and allergens. So all over the country, the population that has the greatest burden of asthma lives in environments where these exposures persist, and children continue to be hospitalized for asthma exacerbations and discharged home without a plan to improve their home environments.
The fix might appear straightforward - send “exterminators” to homes to get rid of the mice. But like many other chronic health conditions that have social and environmental determinants, our systems for improving the health of a community are failing us. Taking mouse exposure as the example, here are the obstacles we face when trying to eradicate infestation and lower levels of mouse allergen in the home:
I have highlighted just one type of home exposure in one city, but these concepts apply to other indoor allergens and pollutants and to all cities with areas of concentrated poverty across the US. The 10,000 foot view of asthma in low-income, mostly minority communities, is that we are struggling to deliver the right medication to patients and monitor their asthma, and against this backdrop we are doing little to address a root cause of their asthma morbidity: their home and neighborhood environments. Ultimately, asthma (and many other chronic health conditions) can be solved, but only by a system that integrates medical services, payment reform, school health, public health, and housing services/policy.