Abstract. We conducted a door-to-door survey in a residential census tract of Philadelphia to estimate the prevalence and spatial patterns of recent bed bug infestations. We interviewed 596 residents, of whom 66 (11.1%) reported recent bed bug infestations. We confirmed current infestations in a subset of 15 (68.2%) of 22 inspected households. Most residents reported that their infestation began within the past year (2012)(2013). We found no correlation between property value and infestation status. Spatial analyses showed significant clustering of bed bug infestations only at fine scales, suggesting limited active dispersal of the insects. Residents used a large variety of treatment methods to eliminate bed bugs, but only 48.1% reported success. Our results provide a prevalence estimate of recent bed bug infestations and highlight the importance of passive rather than active dispersal of bed bugs even among dense urban row homes.

Although not presently implicated as a vector of human pathogens, the common bed bug, , has been suspected of carrying human pathogens because of its close association with humans and its obligate hematophagy. Recently, we characterized the vectorial competence of for the parasite , the causative agent of Chagas disease. We observed that can acquire infection when fed on-carrying mice, and subsequently transmit to uninfected mice. This led us to ask why has not been implicated in the transmission of outside of the laboratory? We hypothesized that reduces fitness (i.e., survival and/or reproduction) as an explanation for why does not to transmit in natural settings. We tested this hypothesis by comparing the survival and reproduction of uninfected and-infected . We observed that had a variable effect on survival and reproduction. There were negligible differences between treatments in juveniles. Infected adult females tended to live longer and produce more eggs. However, no effect was consistent, and infected bugs showed more variation in survival and reproduction metrics than control bugs. We did not observe any negative effects of infection on survival or reproduction, suggesting that decreased fitness in-infected is not why bed bugs have not been observed to transmit in natural settings.