At SRI, we are “committed to discovery and to the application of science and technology for knowledge, commerce, prosperity, and peace.”
My work at SRI fulfills these ideals in a way you wouldn’t expect. I’m trying to solve a problem that acutely affects our most vulnerable populations.
Bed bugs are greater indicators of social inequality than you might think.
We are all at risk for a bed bug introduction. However, we are not all equally at risk for bed bug infestations. Most of us have the resources, physical strength and the social infrastructure to avoid infestations. By “infestation”, I mean dozens or even hundreds of bed bugs feeding on us every night. Yet people living on the margins are more likely to suffer through chronic infestations. This is why bed bugs are increasingly considered more than a public health issue and why I consider my work on bed bugs to be an issue of social justice.
How Did Bed Bugs Become Such a Problem?
The common bed bug feeds on blood and readily feeds on humans. Bed bug bites can cause adverse reactions in humans, including rashes, lesions, dermatitis, allergies, and psychological distress.
Global bed bug infestations were common until the 1930s and 1940s, when the pesticide DDT was first used to control insect pests. From the 1940s until 1972, when the U.S. Environmental Protection Agency (EPA) banned DDT, bed bugs were virtually eradicated from human homes in the developed world. Populations have increased over a hundred-fold in the last twenty years in North America and Europe, representing a significant financial, psychological, and public health burden.
Today’s problem comes from:
Increased resistance of bed bugs to commonly used insecticides.
Increase in international travel. Bed bugs don’t have wings; they get from place to place on us and in our things.
High population density of people in cities. For the first time in human history, most of us live in cities. What does this mean for bed bugs? A high population density of the host means a high population density of the parasite.
Economics. Local classified ad websites have skyrocketed the trade of second- hand furniture, increasing the chance of exposure to bed bugs.
Changing patterns in pesticide use. When we used to spray homes and apartments for roaches, we controlled bed bugs in the process. In the last 20 years, we’ve moved to bait-traps for cockroaches. We’re not spraying to control roaches anymore, and that means we’re not reaping the fringe benefits of controlling bed bugs.
Bed bugs are developing increased resistance
to commonly used pesticides
Why Care About Bed Bugs?
Bed bugs aren’t vectors – meaning they don’t transmit pathogens.
Yet the EPA and Centers for Disease Control and Prevention (CDC) recently proclaimed that bed bugs are a “significant public health concern”. Bed bug bites in enough numbers can lead to anemia, mental health concerns, anxiety, insomnia, and depression.
Unfortunately, most of the news coverage about bed bugs tends to focus on hotels or retailers, giving us the impression that we are at the highest risk for infestation when we visit these places.
In reality, the most vulnerable populations live in low-income housing. They are the physically and mentally disabled, the elderly who may not be able to feel the bites, veterans, and those in homeless shelters, hospitals and psychiatric clinics.
The bottom line is that we are failing these communities.
When I go to these apartments, there are bed bugs embedded under the mattress and under the folds and creases of sofas. Sometimes, there are even bed bugs on walls and doorjambs. I’ll take a piece of masking tape and stick it on a sofa, and pull off eggs, shed exoskeletons, and bed bug parts. Box springs are speckled with droplets of bed bug feces. The characteristic odor, like really fresh cilantro, permeates the apartment. People are eaten alive while they sleep or watch TV.
Tenants on a fixed income feel powerless. They can't afford to treat the infestation, they can't afford to move, and they can't afford to buy new furniture. What options do they have?
Low-income housing and public institutions are often in the same boat as the tenants. It’s becoming more and more expensive to treat infestations, and there’s less money allocated for the job.
How Is SRI Helping?
Allocating more money for treatment might help in the short term, but we need to prevent new introductions to enact lasting change.
One way is to inform public policy and help housing authorities decide on a control strategy to limit the risk of new infestations and control existing ones, saving them money in the process.
SRI has collected bed bugs from a single apartment building: 15 collections from 108 apartment units means 14% of the units had evidence of bed bugs. And by analyzing the genetic makeup of bed bugs from each collection, we can determine the degree of relatedness between these populations.
Where did they come from? Did they radiate from one “hot spot” to all the other units? Or is each infestation an independent event? With colleagues at North Carolina State University and James Madison University, we’re going to perform the bed bug equivalent of a “paternity test” (Those of you who’ve seen CSI or NCIS or Law and Order know what I’m talking about.)
These results will influence how the housing authority plans to control them.
If they’re from, say, one heavily infested apartment, then that single apartment can be treated and monitored for any re-infestation to prevent their spread throughout the building.
However, if each infestation is an independent event – a mattress from a second-hand store, a couch from a disreputable online supplier, cushions from a dumpster – then it will be a lot harder to prevent new infestations. In that case, education for the tenants and services, such as heat or pesticide treatment of new items, could decrease the risk of new infestations.
In addition to the genetic fingerprinting study, we’re also going to screen these 15 samples for “biomarkers” for pesticide resistance.
That way, not only will we know if these populations are related, but we’ll also know what pesticides will or won’t be effective in controlling them.
Our vision at SRI is to use the best tools at our disposal – be they studies of population genetics or of human behavior – to prevent tenants, housing authorities, and the general public from spending unnecessary time and money on futile attempts to control the bed bug problem.
Stay tuned – in my next post I’ll talk about why solving the bed bug problem is so difficult and why both the government and the market need to be proactive in finding effective solutions.