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Rat sightings in New York City are associated with neighborhood sociodemographics, housing characteristics, and proximity to open public space.

Walsh MG - PeerJ (2014)

Bottom Line: Using city-wide records of rat sightings reported to the NYC Department of Health and Mental Hygiene, this investigation sought to identify sociodemographic, housing, and physical landscape characteristics that are associated with increased rat sightings across NYC census tracts.Closer proximity to both subway lines and recreational public spaces was associated with a higher concentration of rat sightings, as was a greater presence of older housing, vacant housing units, and low education among the population.These findings have identified specific features of the NYC urban environment that may help to provide direct control targets for reducing human-rat encounters.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Epidemiology and Biostatistics, School of Public Health, State University of New York , Downstate, Brooklyn, NY , USA.

ABSTRACT
Rats are ubiquitous in urban environments and, as established reservoirs for infectious pathogens, present a control priority for public health agencies. New York City (NYC) harbors one of the largest rat populations in the United States, but surprising little study has been undertaken to define rat ecology across varied features of this urban landscape. More importantly, factors that may contribute to increased encounters between rats and humans have rarely been explored. Using city-wide records of rat sightings reported to the NYC Department of Health and Mental Hygiene, this investigation sought to identify sociodemographic, housing, and physical landscape characteristics that are associated with increased rat sightings across NYC census tracts. A hierarchical Bayesian conditional autoregressive Poisson model was used to assess these associations while accounting for spatial heterogeneity in the variance. Closer proximity to both subway lines and recreational public spaces was associated with a higher concentration of rat sightings, as was a greater presence of older housing, vacant housing units, and low education among the population. Moreover, these aspects of the physical and social landscape accurately predicted rat sightings across the city. These findings have identified specific features of the NYC urban environment that may help to provide direct control targets for reducing human-rat encounters.

No MeSH data available.


Related in: MedlinePlus

The 43,542 rat sightings reported to the NYC Department of Health and Mental Hygiene are plotted with an overlay of recreational public spaces and subway lines in a map of New York City census tracts.Rat sightings: red points. Recreational public spaces: beige polygons. Subway lines: blue lines.
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fig-1: The 43,542 rat sightings reported to the NYC Department of Health and Mental Hygiene are plotted with an overlay of recreational public spaces and subway lines in a map of New York City census tracts.Rat sightings: red points. Recreational public spaces: beige polygons. Subway lines: blue lines.

Mentions: Between January 1, 2010 and March 24, 2014, a total of 43,542 rat sightings were reported to the DOHMH from all five of the city’s boroughs. Figure 1 presents the map of the individual rat sightings across all census tracts along with public spaces and subway lines. Figure 2 presents the kernel density estimate of rat sightings. These maps highlight a concentration of rats in much of northern Manhattan and the South Bronx, the Lower East Side of lower Manhattan, and north-central Brooklyn. When aggregated by census tract, reported rat sightings ranged from 0 to 303 per census tract and the Moran I statistic standard deviate was 38.2 (p < 0.00001) indicating significant spatial clustering of rats across NYC. Figure 3 shows the concentration of rats by census tract in each of three panels juxtaposed with the average distances from rat sightings to public space and to subway lines, sociodemographics, and housing characteristics, respectively. As expected, the distribution of the average distances from rats to subway lines across census tracts follows the prominent line tunnels of the MTA subway system. Census tracts with shorter average distances between sighted rats and subway lines also tend to have a higher concentration of rats. Interestingly, the distribution of the average distances from rats to public space also shares patterns with the distribution of the concentration of rats, suggesting that closer proximity to public space is also associated with a higher concentration of rats. In addition to these landscape features, high concentrations of rats appear to coincide with high concentrations of vacant housing, old housing, and low education in these maps. Estimates of the rat sighting prevalence ratios (PR) from the CAR model are presented in Table 1 along with their associated 95% credible intervals. Both the average distance to subway lines (PR = 0.996; 95% CI [0.993–0.998]) and the average distance to public space (PR = 0.94; 95% CI [0.91–0.97]) were inversely associated with rat sightings. Each 10 m increase in the average distance from subway lines resulted in a 4% decrease in rat sightings, while each 1 m increase in the average distance from public space corresponded to a 6% decrease in rat sightings. Housing factors were also associated with rat sightings, with each percentage increase in the proportion of vacant housing units corresponding to a 2% increase in rats (PR = 1.02; 95% CI [1.018–1.026]) and each 10 percentage point increase in the proportion of old housing demonstrating a 6% increase in rats (PR = 1.006; 95% CI [1.004–1.01]). The proportion of people with less than a high school education was strongly associated with rat sightings (PR = 3.97; 95% CI [1.72–5.70]), while the number of people per census tract was not. The observed rat counts and predicted rat counts for each census tract based on the CAR model are presented in Fig. 4, along with the spatial distribution of the residual deviance. Visual inspection suggests that this model is spatially homogeneous with respect to the residual deviance. Moreover, the Moran’s index for the residual deviance was not significant (Moran’s I statistic standard deviate = 0.78, p-value = 0.22), thus confirming statistically the visual interpretation.


Rat sightings in New York City are associated with neighborhood sociodemographics, housing characteristics, and proximity to open public space.

Walsh MG - PeerJ (2014)

The 43,542 rat sightings reported to the NYC Department of Health and Mental Hygiene are plotted with an overlay of recreational public spaces and subway lines in a map of New York City census tracts.Rat sightings: red points. Recreational public spaces: beige polygons. Subway lines: blue lines.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4157232&req=5

fig-1: The 43,542 rat sightings reported to the NYC Department of Health and Mental Hygiene are plotted with an overlay of recreational public spaces and subway lines in a map of New York City census tracts.Rat sightings: red points. Recreational public spaces: beige polygons. Subway lines: blue lines.
Mentions: Between January 1, 2010 and March 24, 2014, a total of 43,542 rat sightings were reported to the DOHMH from all five of the city’s boroughs. Figure 1 presents the map of the individual rat sightings across all census tracts along with public spaces and subway lines. Figure 2 presents the kernel density estimate of rat sightings. These maps highlight a concentration of rats in much of northern Manhattan and the South Bronx, the Lower East Side of lower Manhattan, and north-central Brooklyn. When aggregated by census tract, reported rat sightings ranged from 0 to 303 per census tract and the Moran I statistic standard deviate was 38.2 (p < 0.00001) indicating significant spatial clustering of rats across NYC. Figure 3 shows the concentration of rats by census tract in each of three panels juxtaposed with the average distances from rat sightings to public space and to subway lines, sociodemographics, and housing characteristics, respectively. As expected, the distribution of the average distances from rats to subway lines across census tracts follows the prominent line tunnels of the MTA subway system. Census tracts with shorter average distances between sighted rats and subway lines also tend to have a higher concentration of rats. Interestingly, the distribution of the average distances from rats to public space also shares patterns with the distribution of the concentration of rats, suggesting that closer proximity to public space is also associated with a higher concentration of rats. In addition to these landscape features, high concentrations of rats appear to coincide with high concentrations of vacant housing, old housing, and low education in these maps. Estimates of the rat sighting prevalence ratios (PR) from the CAR model are presented in Table 1 along with their associated 95% credible intervals. Both the average distance to subway lines (PR = 0.996; 95% CI [0.993–0.998]) and the average distance to public space (PR = 0.94; 95% CI [0.91–0.97]) were inversely associated with rat sightings. Each 10 m increase in the average distance from subway lines resulted in a 4% decrease in rat sightings, while each 1 m increase in the average distance from public space corresponded to a 6% decrease in rat sightings. Housing factors were also associated with rat sightings, with each percentage increase in the proportion of vacant housing units corresponding to a 2% increase in rats (PR = 1.02; 95% CI [1.018–1.026]) and each 10 percentage point increase in the proportion of old housing demonstrating a 6% increase in rats (PR = 1.006; 95% CI [1.004–1.01]). The proportion of people with less than a high school education was strongly associated with rat sightings (PR = 3.97; 95% CI [1.72–5.70]), while the number of people per census tract was not. The observed rat counts and predicted rat counts for each census tract based on the CAR model are presented in Fig. 4, along with the spatial distribution of the residual deviance. Visual inspection suggests that this model is spatially homogeneous with respect to the residual deviance. Moreover, the Moran’s index for the residual deviance was not significant (Moran’s I statistic standard deviate = 0.78, p-value = 0.22), thus confirming statistically the visual interpretation.

Bottom Line: Using city-wide records of rat sightings reported to the NYC Department of Health and Mental Hygiene, this investigation sought to identify sociodemographic, housing, and physical landscape characteristics that are associated with increased rat sightings across NYC census tracts.Closer proximity to both subway lines and recreational public spaces was associated with a higher concentration of rat sightings, as was a greater presence of older housing, vacant housing units, and low education among the population.These findings have identified specific features of the NYC urban environment that may help to provide direct control targets for reducing human-rat encounters.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Epidemiology and Biostatistics, School of Public Health, State University of New York , Downstate, Brooklyn, NY , USA.

ABSTRACT
Rats are ubiquitous in urban environments and, as established reservoirs for infectious pathogens, present a control priority for public health agencies. New York City (NYC) harbors one of the largest rat populations in the United States, but surprising little study has been undertaken to define rat ecology across varied features of this urban landscape. More importantly, factors that may contribute to increased encounters between rats and humans have rarely been explored. Using city-wide records of rat sightings reported to the NYC Department of Health and Mental Hygiene, this investigation sought to identify sociodemographic, housing, and physical landscape characteristics that are associated with increased rat sightings across NYC census tracts. A hierarchical Bayesian conditional autoregressive Poisson model was used to assess these associations while accounting for spatial heterogeneity in the variance. Closer proximity to both subway lines and recreational public spaces was associated with a higher concentration of rat sightings, as was a greater presence of older housing, vacant housing units, and low education among the population. Moreover, these aspects of the physical and social landscape accurately predicted rat sightings across the city. These findings have identified specific features of the NYC urban environment that may help to provide direct control targets for reducing human-rat encounters.

No MeSH data available.


Related in: MedlinePlus