City sanitation and socioeconomics predict rat zoonotic infection across diverse neighbourhoods

Abstract

Rat‐associated zoonoses transmitted through faeces or urine are of particular concern for public health because environmental exposure in homes and businesses may be frequent and undetected. To identify times and locations with greater public health risks from rats, we investigated whether rat characteristics, environmental features, socioeconomic factors, or season could predict rat infection risk across diverse urban neighbourhoods. In partnership with a pest management company, we sampled rats in 13 community areas along an income gradient in Chicago, a large city where concern about rats has increased in recent years. We collected kidneys for Leptospira spp. testing and colon contents for aerobic bacteria such as Salmonella spp. and Escherichia coli. Of 202 sampled rats, 5% carried Leptospira spp. and 22% carried E. coli. Rats were significantly more likely to carry Leptospira spp. on blocks with more standing water complaints in higher‐income neighbourhoods (OR = 6.74, 95% CI: 1.54–29.39). Rats were significantly more likely to carry E. coli on blocks with more food vendors (OR = 9.94, 2.27–43.50) particularly in low‐income neighbourhoods (OR = 0.26, 0.09–0.82) and in the spring (OR = 15.96, 2.90–88.62). We detected a high diversity of E. coli serovars but none contained major virulence factors. These associations between environmental features related to sanitation and infection risk in rats support transmission through water for Leptospira spp. and faecal–oral transmission for E. coli. We also found opposing relationships between zoonotic infection risk and income for these two pathogens. Thus, our results highlight the importance of sanitation for predicting zoonotic disease risks and including diverse urban areas in pathogen surveillance to mitigate public health risks from rats.

Amplification of pathogenicLeptospirainfection with greater abundance and co‐occurrence of rodent hosts across a counter‐urbanizing landscape

“…We created two global models including the following predictor variables: total rodent abundance (an index calculated as the number of all rodents captured per 100 corrected trap nights, following Beauvais & Buskirk, 1999), species richness, and a suite of socio‐environmental variables that either have been found to predict rodent diversity and abundance in New Orleans (Peterson et al., 2020) or that have been shown to relate to Leptospira infection in other urban areas (Desvars‐Larrive et al., 2020; Hagan et al., 2016; Murray et al., 2020; Reis et al., 2008). These were: the proportion of vacant lots, the proportion of unmaintained vegetation, the number of trash and debris piles, median household income, total human population, elevation and trapping season.…”

“…best predict Leptospira infection across New Orleans. We focused on factors that influence Leptospira infection of rodent hosts in other cities (Desvars‐Larrive et al., 2020; Hagan et al., 2016; Murray et al., 2020; Reis et al., 2008), as well as factors that shape the prevalence and distributions of rodents and other rodent‐borne pathogens in New Orleans (Peterson et al., 2017; Peterson et al 2020 ; Rael et al., 2018). Meeting these objectives allowed us to draw globally relevant insights, in part because of the near‐cosmopolitan distributions of rodents found in New Orleans (Aplin et al., 2011; Lund, 1994; Puckett et al., 2016) and because of socioecological parallels that occur between New Orleans and other cities worldwide (Gulachenski et al., 2016; Lewis et al., 2017).…”

Control and prevention of infectious diseases from a One Health perspective

“…Accordingly, poor water supply services lead people to store water in containers, whereas the lack of adequate sewage systems gives rise to open sewers; these factors prove breeding sites for mosquitoes, contributing to an increase in vector-borne diseases (Degroote et al, 2018). The proliferation of other urban pests that can transmit various pathogens to humans, such as rodents, is also favored by inadequate sanitation services (Moreira et al, 2013;Rahelinirina et al, 2019;Murray et al, 2020). The diseases associated with the lack of sanitation also cause severe economic damages to the affected families and to the economy of the countries, since these diseases cause significant losses in working days and huge expenses with the treatment of the affected individuals, among other related issues (Van Minh and Hung, 2011;Fuente et al, 2020).…”

“I don’t feel safe sitting in my own yard”: Chicago resident experiences with urban rats during a COVID-19 stay-at-home order

“…Home environments that contain rat feces or urine can expose residents to a variety of zoonotic pathogens such as Leptospira interrogans , Seoul hantavirus, and infectious organisms such as Escherichia coli and Salmonella spp. [9, 26].…”

“…Resident experiences with rats while staying at home may vary depending on local environmental and social factors. Previous studies have demonstrated that rat abundance and rat-associated health risks vary significantly between neighborhoods [5, 9] and is typically higher in low-income areas [10, 11], likely because of building conditions and resources available to control rats. Residents’ encounters with rats might also differ based on their housing conditions; property owners may face monetary burdens from controlling rats while some renters may have negligent landlords.…”