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Baylisascaris procyonis , the raccoon ( Procyon lotor ) ascarid, is a common roundworm parasite of raccoons that is also a well-recognized zoonotic pathogen, and a cause for conservation concern. The transmission dynamics of B. procyonis differ with host population attributes, season, and landscape. We examined how the parasite's population attributes change with season, parasite population structure, and host demographics. We examined 1,050 raccoon gastrointestinal tracts collected from 1996 to 2012. Of the 1,050 raccoons necropsied, 382 (36%) were infected with at least one B. procyonis (x¯=15.8 [95% confidence interval=13.39-18.26]; median=7; range 1-199 worms/host), and populations were overdispersed. There was a seasonal change in prevalence with a peak in October/November. Worm burdens decreased approximately 28% per month from January to June and increased approximately 31% per month from June to December. The sex structure of B. procyonis populations was female-biased (56% female). Host demographics did not impact parasite population attributes. This study provides evidence that B. procyonis populations exhibit a yearly cycle of loss and recruitment that may impact the transmission dynamics of the parasite.

Baylisascaris procyonis is a common gastrointestinal parasite of raccoons (Procyon lotor) and is a zoonotic helminth with the potential to cause severe or fatal infection. Raccoons thrive in human-dominated landscapes, and the fecal-oral transmission pathway and lack of effective treatment make B. procyonis a serious threat to public health. The distribution of medicinal baits has emerged as a socially acceptable and cost-effective method for managing disease in free-ranging wildlife. We assessed the suitability of a mass-producible anthelmintic bait for B. procyonis mitigation by evaluating the willingness of free-ranging raccoons to consume anthelmintic baits and determining whether bait consumption successfully cleared B. procyonis infections from raccoons. Anthelmintic baits were modified from standard fishmeal polymer baits, the food attractant commonly used in oral rabies vaccine baits, with the introduction of 220 mg of pyrantel pamoate into the fishmeal mixture. We captured 16 naturally infected raccoons, presented one anthelmintic bait, and monitored B. procyonis infection over 90 d by screening feces for eggs. Treatment cleared B. procyonis infections for nine of 12 raccoons that consumed10 g of the 15 g bait. We used remote cameras to monitor in situ patterns of bait consumption for anthelmintic baits relative to standard baits. Both anthelmintic and standard baits were rapidly consumed, with no differences in the rate of consumption between bait types. However, after bait contact, raccoons demonstrated a greater willingness to consume standard baits while ignoring anthelmintic baits more frequently (P = 0.06). Initial trials of anthelmintic baits show promise, although refinement in both dose and palatability is needed. At mass production scales, the addition of pyrantel pamoate to fishmeal polymer baits would be inexpensive, potentially making anthelmintic baits a viable management option when coupled with an oral rabies vaccine or used independently for B. procyonis mitigation.

Raccoon roundworm (Baylisascaris procyonis), a common gastrointestinal parasite of the raccoon (Procyon lotor), has been implicated in population declines of Allegheny woodrats (Neotoma magister). Medicinal baiting is a viable tool in wildlife disease management although unique challenges exist for pathogenic systems in which the host can be immediately re-infected following treatment. Our goals were to evaluate the efficacy of using monthly distribution of anthelmintic baits to reduce the prevalence of B. procyonis infection in raccoons and to quantify patterns and rates of bait acceptance among populations repeatedly exposed to medicinal baits. We distributed baits monthly at a density of 200/km2 throughout 300-m buffer areas surrounding woodrat habitats in Indiana. We conducted raccoon latrine surveys annually to quantify the effect of treatment on roundworm prevalence and used remote cameras to identify the species contacting baits and determine the rate at which baits were removed. We observed declines in B. procyonis prevalence in response to treatment, but our ability to resolve statistical differences was limited by low pretreatment prevalence and high annual variability. Baits were removed rapidly from camera stations with 60% taken within 24 hours, 80% within 48 hours, and 90% within 72 hours. Virginia opossums (Didelphis virginiana) removed 51% of baits whereas raccoons removed 44%. Identification of opossums as the predominant consumer of baits emphasizes the limitations imposed by non-target bait consumption for mitigation of B. procyonis and other wildlife diseases. The rapid removal of baits despite repeated bait exposure suggests that habituation did not result in bait aversion and fishmeal baits are a viable delivery system for mitigation of raccoon-borne diseases requiring repeated treatments. Similar treatment measures may facilitate conservation of Allegheny woodrats in habitats with high rates of B. procyonis-related mortality and could be used to reduce human exposure to this zoonotic parasite. © 2013 The Wildlife Society.

Graphical abstract, Highlights • Baylisascaris procyonis has many of the properties associated with a pathogen capable of facilitating extinction. • Baylisascaris procyonis is highly non-specific with regard to paratenic hosts. • Eggs of B. procyonis accumulate with feces at raccoon latrines, and can remain viable for many years. • Transmission of B. procyonis occurs at raccoon latrines, and is sensitive to changes in land-use. • Conservation strategies for vulnerable species should consider the transmission ecology of parasitic pathogens, like B. procyonis., Human demands on natural resources result in landscape changes that facilitate the emergence of disease. Most emerging diseases are zoonotic, and some of these pathogens play a role in the decline of vulnerable wildlife species. Baylisascaris procyonis, the common roundworm parasite of raccoons (Procyon lotor), is a well recognized zoonotic infection that has many of the properties associated with a pathogen capable of driving extinction. It is highly non-specific and frequently pathogenic with regard to paratenic hosts, which contact eggs of B. procyonis at raccoon latrines. Eggs accumulate at latrines and remain viable for many years. Transmission of B. procyonis is sensitive to changes in land-use, and fragmented habitats increase contact rates between raccoons, potential paratenic hosts, and the parasite. Raccoons, and subsequently B. procyonis, have been introduced to Europe and Japan, where naïve vertebrates may be exposed to the parasite. Finally, domestic animals and exotic pets can carry patent infections with B. procyonis, thus increasing environmental contamination beyond raccoon latrines, and expanding the area of risk to potential paratenic hosts. This parasite can potentially contribute to extinctions of vulnerable species, as exemplified by the case of the Allegheny woodrat (Neotoma magister), a species that has experienced local declines and extinctions that are linked to B. procyonis. Conservation strategies for vulnerable species should consider the transmission ecology of parasitic pathogens, like B. procyonis.

Translocations are an important tool for wildlife conservation, although progress in the field of reintroduction biology has been hindered by the ad hoc and opportunistic nature of many translocations. We used an experimental translocation to elucidate the role of raccoon roundworm (Baylisascaris procyonis) and inbreeding depression in the decline of the Allegheny woodrat (Neotoma magister), an endangered species. We translocated woodrats from genetically diverse populations in the core of the species range to 4 previously occupied sites (reintroductions) and 2 sites supporting genetically depauperate populations (reinforcements) in Indiana (U.S.A.). In 2 reintroduction sites and 1 reinforcement site, we distributed anthelmintic baits to passively deworm raccoons and reduce the risk of woodrat exposure to roundworms. The remaining sites served as controls. We used raccoon latrine surveys and fecal flotation to monitor temporal variability in roundworm prevalence and effect of treatment. We used live trapping and microsatellite genotyping to monitor the demographic and genetic response of translocated populations over the following 54 months. At the conclusion of the study, 4 of 6 translocations were successfully maintaining abundance through local recruitment. The distribution of anthelmintic baits reduced levels of roundworm contamination, but levels of contamination were also low in 2 of 3 control sites. Reintroductions failed at control sites, one of which was due to high roundworm exposure. The other failed control reintroduction was likely attributable to demographic stochasticity and limited reproductive potential following initial mortality within the first 4 months. In both control and treatment reinforcements, increases in both allelic richness and heterozygosity were accompanied by increases in abundance, which is suggestive of genetic rescue. Our results demonstrate that mitigation of roundworm exposure through the distribution of anthelmintic baits can facilitate woodrat recovery and that diversity within genetically depauperate populations can be restored through the introduction of a limited number of individuals. El Uso de Reubicaciones Experimentales de Neotoma magister para Descifrar Agentes Causales de Disminucion Resumen Las reubicaciones son una herramienta importante para la conservacion de la vida silvestre aunque el progreso en el campo de la biologia de la reintroduccion ha sido dificultado por la naturaleza ad hoc y oportunista de muchas reubicaciones. Usamos una reubicacion experimental para dilucidar el papel del nematodo del mapache (Baylisascaris procyonis) y la depresion endogamica en la disminucion de Neotoma magister, una especie en peligro. Reubicamos individuos de poblaciones geneticamente diversas en el nucleo del rango de la especie a 4 sitios previamente ocupados (reintroducciones) y a 2 sitios que soportaban poblaciones geneticamente depauperadas (reforzamientos) en Indiana (E.U.A.). En 2 sitios de reintroduccion y en uno de reforzamiento distribuimos cebos antihelminticos para desparasitar pasivamente a los mapaches y reducir el riesgo de exposicion de Neotoma magister a nematodos. Los sitios restantes sirvieron como controles. Usamos censos de letrinas de mapache y flotacion fecal para monitorear la variabilidad temporal en la prevalencia de nematodos y el efecto del tratamiento. Usamos capturas y genotipeo microsatelital para monitorear las respuestas demograficas y geneticas de las poblaciones reubicadas durante los 54 meses siguientes. En la conclusion del estudio, 4 de 6 reubicaciones estaban manteniendo exitosamente la abundancia a traves del reclutamiento local. La distribucion de cebos antihelminticos redujo el nivel de contaminacion de nematodos pero los niveles de contaminacion tambien fueron bajos en 2 de 3 sitios de control. Las reintroducciones fallaron en los sitios de control, uno debido a la alta exposicion a nematodos. La otra reintroduccion control fallida se atribuye probablemente a la estocasticidad demografica y el potencial reproductivo limitado despues de la mortalidad inicial de los primeros 4 meses. En ambos reforzamientos control y con tratamiento, los incrementos tanto en riqueza alelica como heterocigocidad estuvieron acompanados por incrementos en abundancia, lo que sugiere un rescate genetico. Nuestros resultados demuestran que la mitigacion de la exposicion a nematodos a traves de cebos antihelminticos puede facilitar la recuperacion de Neotoma magister y que la diversidad dentro de poblaciones geneticamente depauperadas puede restaurarse por medio de la introduccion de un numero limitado de individuos.

Baylisascaris procyonis is an intestinal parasite of raccoons (Procyon lotor) that can also infect humans and a wide range of wildlife species. Prevalence of B. procyonis in raccoon populations appears to decrease as the landscape urbanizes, but less is known about prevalence in the small-mammal intermediate hosts of the parasite. We measured prevalence of B. procyonis in populations of mice (Peromyscus spp.) in forest preserves along a gradient of urbanization in Illinois. Prevalence in the mouse intermediate host exhibited a trend opposite raccoons: prevalence increased as surrounding human population density increased. This counterintuitive result may be due to higher overall environmental loads of B. procyonis in urban areas due to higher raccoon densities. Our results emphasize the need to understand fully the transmission dynamics of B. procyonis in its definitive and intermediate hosts in order to design and implement effective strategies to mitigate zoonotic risks to humans.

Raccoon (Procyon lotor) latrine surveys are an efficient and cost-effective method to quantify Baylisascaris procyonis exposure risk for intermediate hosts. Nevertheless, current methodologies may introduce bias by homogenizing scats collected within latrines and estimating exposure risk at the latrine scale. The objective of this study was to examine the potential for raccoon latrine size to bias estimates of risk of exposure when utilizing current methodologies that pool scats prior to analysis. We accomplished this by evaluating correlation of the presence of B. procyonis eggs among scats collected within latrines. Specimens were collected in southern Indiana during November and December of 2006. Raccoon scats collected within latrines exhibited no correlation with the presence of B. procyonis eggs. Accordingly, to eliminate the bias introduced by pooling scats within latrines, scats rather than latrines should be treated as the sampling unit for estimating risk of exposure for intermediate hosts. Further, evaluation of exposure risk based on individual scats has the potential to greatly reduce the time and expense associated with obtaining precise estimates of B. procyonis exposure risk.

Parasite transmission is a dynamic process that can be affected by factors including host and parasite population dynamics. Raccoons ( Procyon lotor ) are the definitive host of Baylisascaris procyonis , an intestinal roundworm. Transmission of this parasite has been linked to raccoon behavior and human land-use patterns; however, we do not know the importance of host population structure. Therefore, the objective of this study was to determine the relationship between raccoon population attributes and prevalence of B. procyonis. We necropsied 307 trapped or road-killed raccoons collected during 2000-2006 from the Chicago area. In addition, we examined, via fecal samples (n = 433), the patterns of B. procyonis prevalence as they relate to population dynamics among 3 subpopulations within the larger study. Baylisascaris procyonis was seen in 39% of 307 necropsied raccoons. There were differences in prevalence as a function of host age and sex. Baylisascaris procyonis was observed in 18% of 433 fecal samples obtained from live-trapped raccoons, and there were differences according to age, but not by sex. We found that the host populations consistently differed in density across study areas, but were similar regarding sex and age structure. Differences in host density were associated with differences in prevalence, suggesting that possible differences between populations, as well as ecological differences in sites and raccoon behavior, may have influenced parasite prevalence.

Baylisascaris procyonis , the raccoon roundworm, is increasingly being recognized for its zoonotic and public health importance. Fine-scale analyses of the population genetics of this species have been hampered due to a lack of appropriate genetic markers. To this end, we developed 8 novel polymorphic microsatellites for B. procyonis and used these markers to elucidate microgeographic structuring of this parasite in a 500-km(2) study area in western Michigan. Our analyses revealed significant levels of genetic differentiation amongst the 74 worms collected from 10 different raccoons. Critically, Bayesian clustering indicated 2 genetically distinct groups, one on either side of the Grand River which bisects our study area. Estimates of F(ST), and results from AMOVA and isolation by distance, further corroborated a scenario whereby the river is acting as a barrier to gene flow, a rather unexpected finding given the high vagility of raccoons and microgeographic scale of the analysis. It is possible that the Grand River is a major dispersal barrier for B. procyonis because raccoons are most likely to disperse across the river when it is frozen, and worm burden in raccoons approaches zero during the winter.

The raccoon (Procyon lotor) is the definitive host of Baylisascaris procyonis, a large intestinal roundworm. The prevalence of infection among raccoon populations often is high, and in the midwestern United States B. procyonis is documented in 68–82% of raccoons. Because raccoon populations appear to be increasing in response to changes in human land use and because B. procyonis is considered an emerging zoonotic disease, it is important to determine reliable methods to monitor prevalence of infection among raccoons. We compared the relative sensitivity of 3 common methods used by wildlife biologists to determine prevalence in free-ranging raccoon populations. We determined prevalence of infection among midwestern raccoon populations from 456 raccoon fecal samples, 742 raccoon latrine samples, and 212 necropsies (gut analysis). We developed logistic regression models in order to predict the log likelihood of presence of B. procyonis in a given sample as a function of season, land use, and technique. Finally, we measured the sensitivity of fecal sampling by evaluating fecal samples taken from 72 necropsies for the presence of B. procyonis eggs. Necropsy analysis yielded the highest measure of prevalence (44%), followed by latrine samples (22.5%), and fecal samples (17.5%). Necropsy analysis explained the most variance in logistic models, suggesting that this is the most reliable method. However, this technique is labor-intensive and may not be the most efficient method for large-scale investigations of B. procyonis prevalence. Fecal analysis is a reliable method of determining prevalence among raccoons as we observed B. procyonis eggs in 66% of fecal samples taken from positive necropsies. Latrine sampling may be the most efficient method and perhaps the best estimator of zoonotic potential; however, wildlife managers should realize that this measure often is an underestimate of prevalence among raccoons and develop management plans accordingly.

Baylisascaris procyonis is a common roundworm of raccoons that causes severe clinical disease in many vertebrates, including humans. The distribution of B. procyonis in the US is poorly documented in portions of its range and has not been reported from Wyoming. Our objectives were to determine the statewide distribution and prevalence of this parasite in raccoons in Wyoming, using intestinal and fecal examinations. We examined 363 raccoons from 23 Wyoming counties in 2009-11, testing the reliability of two methods (intestinal extrusion and incision) to determine worm burdens. We found 163 raccoons (45%) positive for B. procyonis. The two methods of examination did not differ, although extrusion missed some infections. Neither age nor sex affected apparent prevalence or worm burdens. Prevalence did not differ with land use, yet burden was highest among rural raccoons. Fecal examination revealed that juvenile raccoons had a higher proportion of patent infections than adults, but neither sex nor location were indicators of prevalence. Egg density (eggs per gram of feces) did not differ by sex or age; however, rural raccoons had higher egg densities than urban/suburban animals. Understanding the distribution and prevalence of B. procyonis in Wyoming, especially in and around highly populated areas, is an important step in educating the general public and medical community on the potential risks of raccoon roundworm infection.

Baylisascaris procyonis is a parasitic nematode of raccoons (Procyon lotor) capable of infecting many species of small vertebrates as intermediate hosts. In these hosts, migrating larvae often cause fatal or severe central nervous system (CNS) disease. Previous research suggested that intermediate hosts become infected with B. procyonis while visiting raccoon latrines. We tested effects of ambient availability of food and duration of exposure on dynamics of transmission of B. procyonis to white-footed mice (Peromyscus leucopus )i n a factorial design within enclosures containing artificially constructed raccoon latrines. Fifty percent of experimental mice acquired B. procyonis infections and 43% of infected mice developed CNS disease. Visitation to latrines was marginally greater (P 5 0.095) for mice subjected to low availability of ambient food. The mean number of larvae per mouse was greater (P 5 0.001) in low food group after exposures of 14‐28 days. Probability of infection varied predictably as a function of duration of exposure ( P 5 0.005), and probability of CNS disease varied predictably as a function of level of ambient food available (P 5 0.023). We conclude that transmission of B. procyonis occurs at raccoon latrines and that increased visitation to latrines and duration of residence in close proximity to a latrine, both increase probability of mortality due to CNS disease, especially when individuals are stressed by reduced resources or poor habitat.

Page, L. K., Swihart, R. K. and Kazacos, K. R. 2001. Changes in transmission of Baylisascaris procyonis to intermediate hosts as a function of spatial scale. – Oikos 93: 213–220. Physical changes in landscapes alter the abundance and distribution of species. Higher-order effects can occur when changes in ecological processes result in altered interspecific interactions and subsequent changes in a species’ abundance or persistence. Baylisascaris procyonis, a roundworm parasite of raccoons (Procyon lotor), is pathogenic to numerous small vertebrates that serve as intermediate hosts, including white-footed mice (Peromyscus leucopus). Raccoons have responded positively to agriculturally induced changes in landscapes, with potential consequences for intermediate hosts of B. procyonis. We examined white-footed mice from a homogeneous, predominantly forested landscape in south-central Indiana and a heterogeneous, predominantly agricultural landscape in northwestern Indiana for presence of larval B. procyonis. We compared prevalence of infection, intensity of infection, and average number of larvae per mouse between the landscapes, and among forest patches within the highly fragmented agricultural landscape. Prevalence, intensity of infection, and average number of larvae were significantly higher in the highly fragmented landscape. Within the agricultural landscape, regression models predicted probability of infection, intensity of infection, and average number of larvae per mouse per patch as functions of forest patch area and isolation. We conclude that positive responses of raccoons to agriculturally induced fragmentation of forests have resulted in increased encounter rates between white-footed mice and infective stages of B. procyonis between and within landscapes, resulting in increased transmission of the parasite to intermediate hosts.

Raccoons (Procyon lotor) habitually defecate at preferred sites (latrines). Feces at latrines often harbor eggs of the roundworm Baylisascaris procyonis, a parasite of raccoons that is pathogenic to numerous species of small vertebrates. Undigested seeds are also commonly found in raccoon feces, the composition varying with availability of seed types. Thus, feces at latrines may serve as a source of food and pose a mortality risk for small granivores. To examine this interaction, we manipulated the seed composition in feces at simulated raccoon latrines and tested for differences in vertebrate visitation rates as a function of seed type. Treatments involved placing seeds, including corn, cherry ( Prunus virginiana), dogwood (Cornus racemosa), and a combination of the three types, at simulated raccoon latrines. Using TrailmasterTM camera systems we documented 2406 vertebrate visits by 16 mammal and 11 bird species during 455 camera-nights. Small granivorous mammals, including white-footed mice (Peromyscus leucopus) and eastern chipmunks (Tamias striatus), were the most common visitors. Visitation by white-footed mice was significantly greater when corn, the most preferred seed type, was present in raccoon feces. Visitation by eastern chipmunks and other vertebrate species did not vary with seed type. Active foraging was documented for five vertebrate species and accounted for 10% of all recorded events. We conclude that raccoon latrines are routinely visited by a variety of vertebrate species, especially small granivores. Active foraging for seeds in raccoon feces is an important risk factor for transmission of B. procyonis to small vertebrates, and white-footed mice may suffer elevated rates of infection when corn is present in raccoon feces.

Genetic polymorphisms were investigated in fishers (Martes pennanti) using horizontal starch gel electrophoresis of allozymes. During the 1996–1997 fisher trapping season muscle and liver samples were collected from animals in New Hampshire, New York, Wisconsin, and West Virginia, whereas blood samples were collected from New Hampshire and New York animals only. A total of 30 gene loci were resolved from muscle, liver and blood samples. For the entire pooled sample, the mean multilocus heterozygosity (direct count) was 0.047 and the percentages of loci polymorphic (0.95 criterion and 0.99 criterion) were 20.8 and 45.8, respectively.

Baylisascaris procyonis, the common large roundworm of raccoons (Procyon lotor), causes clinical neurologic disease in many species of mammals and birds. Infective eggs of B. procyonis are present at raccoon latrine sites, and these sites may be important in the transmission of this parasite to syntopic small vertebrates in forested areas. We located raccoon latrines in forested sites in Indiana, sampled soil and fecal material from these locations, and examined these samples for the presence of Baylisascaris procyonis eggs. We also quantified the structural characteristics of raccoon latrines in wooded areas, compared their characteristics with randomly located sites, and classified sites based on structural features using stepwise discriminant function analysis. B. procyonis eggs were present at 14% of the raccoon latrines sampled. Latrine sites differed from randomly located sites and exhibited characteristics generally associated with treefall gaps. Most latrines were located either on logs (...

Translocations are an important tool for wildlife conservation, although progress in the field of reintroduction biology has been hindered by the ad hoc and opportunistic nature of many translocations. We used an experimental translocation to elucidate the role of raccoon roundworm (Baylisascaris procyonis) and inbreeding depression in the decline of the Allegheny woodrat (Neotoma magister), an endangered species. We translocated woodrats from genetically diverse populations in the core of the species range to 4 previously occupied sites (reintroductions) and 2 sites supporting genetically depauperate populations (reinforcements) in Indiana (U.S.A.). In 2 reintroduction sites and 1 reinforcement site, we distributed anthelmintic baits to passively deworm raccoons and reduce the risk of woodrat exposure to roundworms. The remaining sites served as controls. We used raccoon latrine surveys and fecal flotation to monitor temporal variability in roundworm prevalence and effect of treatment. We used live trapping and microsatellite genotyping to monitor the demographic and genetic response of translocated populations over the following 54 months. At the conclusion of the study, 4 of 6 translocations were successfully maintaining abundance through local recruitment. The distribution of anthelmintic baits reduced levels of roundworm contamination, but levels of contamination were also low in 2 of 3 control sites. Reintroductions failed at control sites, one of which was due to high roundworm exposure. The other failed control reintroduction was likely attributable to demographic stochasticity and limited reproductive potential following initial mortality within the first 4 months. In both control and treatment reinforcements, increases in both allelic richness and heterozygosity were accompanied by increases in abundance, which is suggestive of genetic rescue. Our results demonstrate that mitigation of roundworm exposure through the distribution of anthelmintic baits can facilitate woodrat recovery and that diversity within genetically depauperate populations can be restored through the introduction of a limited number of individuals.

Blood flukes in the genus Schistosoma are important human parasites in tropical regions. Genetic heterogeneity of the parasite contributes to the observed phenotypic variation in this host—parasite interaction and may play a role in disease epidemiology. In this paper, we describe the characterization of five polymorphic microsatellite loci from the human blood fluke Schistosoma mansoni , which can now be applied in assessments of schistosome genetic diversity. The five loci revealed extensive polymorphism, as 5—8 alleles per locus were detected among five isolates (from both human patients and snail intermediate hosts) from two Brazilian villages.

The raccoon (Procyon lotor) is the definitive host of Baylisascaris procyonis, a large intestinal roundworm that is zoonotic and can result in fatal or severe central nervous system disease in young children. Prevalence of infection among raccoon populations often is high, and in the midwestern United States, B. procyonis has been reported in 68-82% of raccoons. Raccoon populations have increased in response to changes in human land use, and often reach higher densities in urban and suburban landscapes than rural landscapes. However, shifts in foraging behavior among urban raccoons could impact the transmission of B. procyonis if small vertebrate intermediate hosts are not a significant part of the raccoon diet. The objective of this study was to compare prevalence of B. procyonis infection between urban and rural raccoon populations on a regional scale. Necropsy was done on 204 raccoons collected from September through February during 2000-2005 from seven states across the Midwest (regional sample). Baylisascaris procyonis was found in 54% of examined raccoons. Prevalence differed between land-use types (chi2=11.56, df=1, P=0.0007), and was higher among animals collected from rural locations (65%) than those collected in urban locations (41%). Intensity of infection also differed (F=5.52, df=1, P=0.02), with rural raccoons having greater worm burdens (x=29.63+/-36.42) than urban raccoons (x=13.85+/-18.47). Despite high densities of raccoons in urban landscapes, fewer urban raccoons were infected with B. procyonis, suggesting decreased dependence on intermediate hosts as a food source. This possible explanation was supported by a similar trend in prevalence among subsamples of raccoons collected from three Chicago-area populations (local samples) with differing levels of urbanization, population densities, and foraging behavior that had been intensively monitored during 1995-2002. Decreased transmission of B. procyonis in urban landscapes may be due to decreased predation of intermediate hosts, and contact of juvenile raccoons with B. procyonis eggs may be an important factor in maintaining infections within such populations.

Medicinal baits are distributed to manage zoonotic diseases, including raccoon (Procyon lotor) rabies, but efficient distribution strategies are needed for suburban environments. We developed an automated dispenser that transfers fishmeal polymer baits at user-specified intervals from a magazine to a receptacle fitted with a filter that exploits raccoon dexterity to limit consumption by nontarget species. We introduce the concept of automated dispensers and describe bait removal success rates for raccoons versus nontarget species. We monitored visitation with remote cameras after deploying a dispenser, programmed to present two baits per night, in three disjunct forest patches in northwest Indiana. Raccoons removed 72% of baits; nontarget, white-footed mice (Peromyscus leucopus) removed 11%; Virginia opossums (Didelphis virginiana) removed 9%. Bait removal success varied significantly between raccoons (76%) and opossums (21%), improving bait delivery specificity relative to hand baiting. Accumulation of baits in receptacles resulted in excess (more than one) bait consumption (39% of baits consumed by raccoons were excess), suggesting design improvements are needed to present additional baits only after previous baits have been consumed. Automated dispensers successfully sustained bait availability throughout the operational period. Subsequent research is needed to determine whether a sustained availability of baits achieved with automated dispensers is more effective for the treatment of raccoons in suburban environments than traditional distribution methods.

Raccoons (Procyon lotor) frequently establish defecation sites, termed latrines, on large logs, stumps, rocks, and other horizontally oriented structures/surfaces. These latrines are important foci of infective eggs of Baylisascaris procyonis, a nematode parasite of raccoons which is pathogenic to numerous species of mammals and birds. To examine the role of raccoon latrines in this animal-parasite interaction, we documented animal visitations to raccoon latrines in two large forested tracts and two woodlots in Indiana (USA) during 1994 and 1995. Species richness of vertebrate visitors did not differ between sites or years, but species composition differed by site and year. Fourteen mammal and 15 bird species were documented visiting raccoon latrines. Small granivorous mammals, including white-footed mice (Peromyscus leucopus), eastern chipmunks (Tamias striatus), and tree squirrels (Sciurus carolinensis, S. niger, Tamiasciurus hudsonicus) were the most common visitors to latrine sites. White-footed mice, chipmunks, white-breasted nuthatches (Sitta carolinensis), and opossums (Didelphis virginiana) were photographed foraging on undigested seeds in raccoon feces. Active foraging at latrines also was shown experimentally; seeds embedded in raccoon feces were removed at a greater rate at latrine sites than at nonlatrines. We conclude that raccoon latrines are visited routinely by a variety of vertebrates, especially small granivorous rodents and birds which forage for seeds in raccoon feces, and that raccoon latrines are probable sites of transmission of B. procyonis to susceptible mammals and birds.