A team of researchers have developed a mathematical model and new state policies requiring landlords to report a unit’s recent bedbug infestations to potential tenants.

This policy may raise costs to landlords over the short-term but through the long-term offers a way to reduce infestations, which would lower costs. This mathematical model evaluates the costs and benefits of city and state policies requiring landlords to report recent bed bug infestations.

This model states the disclosure as an effective control policy to reduce the prevalence of infestations and can lead to five-year cost increases to landlords but will ultimately result in long-term savings to landlords. Disclosure also saves tenants money from the first year of implementation. Disclosure could also reduce the threat as well as cost to private homeowners of spreading infestations.

“The treatment costs will out with any vacancy costs,” said Chris Rehmann, an associate professor of civil, construction and environmental engineering, who is involved in the study.

Researchers, during their workshops, heard real stories of bedbug infestations, their effects on people and the struggle to get rid of them. These bugs feed on human blood, causing rashes, allergies, sleep loss, itching and anxiety. Infestations also cause social, psychological, and economic problems and the bugs are very difficult to eliminate from homes.

The Proceedings of the National Academy of Sciences recently published a paper reporting the researchers’ findings. The author is Michael Levy, an associate professor of biostatistics, epidemiology and informatics at the University of Pennsylvania’s Perelman School of Medicine. The co-authors are Rehmann; Sherrie Xie, a doctoral student who is also at Pennsylvania’s Perelman School of Medicine; and Alison Hill, a research fellow for Harvard University’s Program for Evolutionary Dynamics.

Rehmann, a civil, construction and environmental engineer, usually focuses his studies on the mixing in rivers and lakes. However, due to his expertise in mathematical modeling and his prior work with Daniel Schneider who began this study, Rehmann was brought into the study.

Schneider, a professor of urban and regional planning at the University of Illinois, was traveling and picked up bed bugs and had a rough time to reduce the infestation, so he then started this study.

 “When I as at one the workshops I was the only person from Iowa,” Rehmann said. “There were three places that had this policy which were New York, San Francisco and Mason City, Iowa. When they told me that, they asked me why Mason City? I didn’t know; it was really an outlier. Now I say why isn’t the rest of the country catching up to Mason City?”

The primary supporter of the study was The National Socio-Environmental Synthesis Center. Other supporters are The Bill and Melinda Gates Foundation and the National Institutes of Health and The NIH.

Bedbugs have re-emerged as a national and worldwide problem over the past 20 years, the researchers wrote. 

“Were hoping that this work will help inform the policy makers and they’ll adopt it,” Rehmann said.