Exposures to Urban Wildlife and Ectoparasitic Insects among Homeless Persons in Boston, MA

摘要

Urban homeless persons in the United States spend extended periods of time outdoors and may live in crowded conditions with poor hygiene. These settings may increase exposure to animal and insect vectors of disease, including wild rodents, feral cats, wild birds, lice, fleas, and ticks. Despite these risks, assessments of the frequency and risk factors for zoonotic and vector-borne infections among homeless people are limited. To address frequency of exposure to potential sources of zoonotic and vector-borne disease, we queried a cross-sectional sample of patients served by Boston Health Care for the Homeless Program's primary care facility (n=194) as to their sightings of urban wildlife and experiences with ectoparasitic insects. Nearly thirty percent of participants reported daily rodent sightings, and 25% reported daily sightings of cats. Body lice and fleas were reported by 4% and 11% of participants, respectively. Individuals who slept outdoors had more than 13 times the odds of greater frequency of rodent sightings in the last three months compared with those who did not sleep on the street (OR: 13.3; p=0.001; 95% CI: 2.7, 65.3). Heavy drinking was significantly associated with greater frequency of sightings of rodents (OR: 2.5 (1.0, 6.4); p=0.05), cats (4.5 (1.8, 11.5); p=0.002) and dead birds (3.3 (1.4, 7.9); p=0.007). Heavy drinking was also positively associated with ever-experiencing a parasite infestation during periods of homelessness (p=0.03). Frequent sightings of rodents and rodent feces by homeless people in particular may indicate human exposure risk to urban rodent-borne pathogens, including Leptospira spp, Seoul hantavirus, and Rickettsia akari. Exposure to cats suggests that Bartonella henselae infection in homeless persons is worthy of investigation. These infections may be underreported or misdiagnosed in this population. Studies of zoonotic and vector-borne infections among persons experiencing homelessness are warranted.