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Baylisascaris procyonis is a zoonotic nematode commonly found in raccoons (Procyon lotor). Human-altered landscapes can support dense populations of raccoons, increasing the potential for interaction between humans and these animals. We used raccoon feces provided by licensed fur trappers to investigate environmental variables that influence prevalence of B. procyonis at 2 sites in Wisconsin. Trappers submitted raccoon feces to us, along with information on sex, age (juvenile and adult), and approximate trap location for each animal. We used zinc sulfate (1.18 specific gravity) flotation to detect B. procyonis eggs in approximately 1 g of fecal matter from each host. We used ArcView software to determine the distance of each trap location to an urban area as determined by the U.S. Census Bureau in 2000. We compared the habitat components in buffered home ranges (0.805 km around trap locations) of infected animals with those from uninfected animals using Mann-Whitney U-tests (P0.05). Variables investigated were human population, road density, housing units per census block, and land cover, including area of agriculture, forest, developed, shrubland, water, and grassland. We positively identified eggs in 64.9% of the animals sampled. Raccoons infected with B. procyonis had significantly larger area of agricultural habitats and significantly smaller areas of forested habitats in buffered home ranges than uninfected individuals. We found that raccoons near Madison and Milwaukee, Wisconsin, are commonly infected with B. procyonis , indicating that public education regarding protection from disease is warranted.

Human babesiosis in the United States is caused most commonly by the intraerythrocytic protozoan parasite, Babesia microti . Although a few reports have described evidence of Babesia species in animals in Florida, to date Babesia microti specifically has not been reported from Florida or most other southern states. To determine if the organism is present in vertebrates in the region, small mammals were trapped and sampled at 2 sites in northeastern Florida, and DNA extracts from blood samples were screened for B. microti DNA via PCR assays targeting portions of the nuclear small subunit rRNA (18S rDNA) and beta-tubulin genes. Amplified fragments from representative samples of PCR-positive hosts were sequenced and compared phylogenetically to reference strains of Babesia species. The B. microti strains found in cotton rats ( Sigmodon hispidus ) most closely resembles B. microti sensu stricto strains that are pathogenic to humans, and strains found in raccoons ( Procyon lotor ) most closely resembles previously described raccoon-related strains of B. microti sensu lato. The results of this study suggest that B. microti is prevalent among cotton rats and raccoons at some sites in northeast Florida and may pose a risk to humans in the region.

The reproductive strategies and variation in reproductive success of ticks are poorly understood. We determined variation in multiple paternity in the American dog tick Dermancentor variabilis . In total, 48 blood-engorged female ticks and 22 male companion ticks were collected from 13 raccoon ( Procyon lotor ) hosts. In the laboratory, 56.3% of blood-engorged females laid eggs, of which 37.0% hatched or showed signs of development. We examined the presence of multiple paternity in the ensuing clutches by genotyping groups of eggs and larvae at 5 microsatellite loci and subtracting the known maternal alleles, thereby identifying male-contributed alleles. Seventy-five percent of the clutches presented multiple paternity, with a mode of 2 fathers siring the clutch. Males associated with the females on the host always sired some offspring. In 1 case, a male was the sire of clutches derived from 2 females, indicating both polygyny and polyandry may occur for this species. These results, combined with those of several other recent studies, suggest that multiple paternity might be frequent for ixodid ticks.

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.

The protozoon Toxoplasma gondii has a worldwide distribution and affects many species of warm-blooded animals. In the Canadian prairies, mesocarnivores such as striped skunks (Mephitis mephitis) and raccoons (Procyon lotor) have experienced an increase in density and distribution, and they are in close contact with human dwellings. However, there has been no systematic study on the seroprevalence of T. gondii in these mesocarnivore populations. The objectives of the current project were to determine the serum antibody prevalence of T. gondii in Canadian prairie mesocarnivores and to study the relationship between antibody prevalence and species, sex, age, location, and year of collection. Antibodies to T. gondii were found in 5 of 24 (20.8%) skunks from Saskatchewan trapped in 1999 and 5 of 40 (12.5%) in 2000. Seroprevalences for T. gondii in raccoons and skunks trapped in Manitoba were 2 of 10 (20%) raccoons trapped in 2002, 7 of 44 (15.9%) trapped in 2003, and 16 of 37 (43.2%) trapped in 2004; and in 13 of 99 (13.1%) skunks trapped in 2003, 29 of 131 (22.1%) trapped in 2004, 53 of 165 (32.1%) trapped in 2005, and 30 of 51 (58.8%) trapped in 2006. Age, location, and year, but not the host species, were important variables in the determining the seroprevalence of T. gondii in skunks and raccoons. Results confirm that T. gondii is endemic in the skunk and raccoon populations in the Canadian prairies.

From 2004 to 2006, 511 raccoons collected by the United States Department of Agriculture Wildlife Services as part of a study to evaluate the effects of mesomammalian predator removal on bobwhite-quail reproduction, were examined for the presence of Gnathostoma procyonis, a nematode that parasitizes the stomach of its definitive host, the raccoon. One hundred forty-one raccoons (27.6%) contained G. procyonis, with males being equally infected (27.5%) as females (27.8%). Mean intensity did not differ significantly between sexes (males-mean = 2.88, range 1-17; females-mean = 2.78, range 1-10) or between collection sites. A significant seasonal prevalence of G. procyonis was noted with a peak in March (43.3%, n = 120) and a minimum in September (5.4%, n = 37). Both collection sites exhibited significant seasonal decreases in G. procyonis, but were not significantly different from each other. There was no cumulative seasonal pattern in mean intensity of G. procyonis, and no seasonal pattern at either collection site. Host weight was not related to either G. procyonis prevalence or mean intensity. Host removal did not have an apparent effect on prevalence or mean intensity of G. procyonis.

Strongyloides procyonis Little, 1966 was detected about 45 years ago in raccoons (Procyon lotor) of southern Louisiana, U.S.A., and was demonstrated experimentally to cause creeping eruption and a short-lived intestinal infection in a healthy human volunteer. After its description and demonstration of its pathogenicity in humans, S. procyonis has not been found in raccoons in North America despite repeated surveys. During a survey on feral raccoons in Japan, S. procyonis parasitic females were identified in 66 (28.3%) of 233 raccoons collected between May 2004 and January 2005. The number of parasitic females recovered from individual raccoons was 1-197 (geomean, 3.2). Both the morphological features and the nucleotide sequences of the small and large subunit ribosomal RNA genes (SSU/LSU rDNA) of S. procyonis closely resembled those of zoonotic Strongyloides stercoralis. The sequences of internal transcribed spacer (ITS)1 and 28S rDNA could differentiate clearly these 2 species. Awareness of S. procyonis in raccoons in North America and other places worldwide where raccoons are introduced and naturalized is important to assess the epidemiological significance of this potentially zoonotic helminth species.

Babesiosis is a tick-borne protozoan disease affecting many mammalian species worldwide, caused by the intraerythrocytic multiplication of Babesia spp. The present study aimed to detect the presence of Babesia sp. in 13 American mink from Hokkaido, Japan. One of 13 animals was positive, as indicated by nested PCR targeting the 18S ribosomal RNA (SSU rDNA) and subunit 7 (eta) of the chaperonin-containing t-complex polypeptide 1 (CCT7) genes from species of Babesia and Theileria. Sequencing of the PCR product of SSU rDNA revealed 99% homology to the isolates of Babesia sp. SAP#131 found in raccoons in Hokkaido, whereas that of the CCT7 gene showed 80% homology to the isolates of Babesia gibsoni in dogs as determined by BLAST analysis. We refer to the cognate sequence as Babesia sp. NV-1. Phylogenetic analyses of SSU rDNA and CCT7 genes from Babesia sp. NV-1 revealed them to be most closely related to the Babesia sp. SAP#131 from a raccoon in Hokkaido and to canine B. gibsoni, respectively. Here, we provide the first molecular evidence of the Babesia sp. NV-1 parasite in feral American mink ( Neovison vison ) in Hokkaido, Japan.

Of the 18 trematode species that use the horn snail, Cerithidea californica, as a first intermediate host, 6 have the potential to use raccoons as a final host. The presence of raccoon latrines in Carpinteria Salt Marsh, California, allowed us to investigate associations between raccoons and trematodes in snails. Two trematode species, Probolocoryphe uca and Stictodora hancocki, occurred at higher prevalences in snails near raccoon latrines than in snails away from latrines, suggesting that raccoons may serve as final hosts for these species. Fecal remains indicated that raccoons fed on shore crabs, the second intermediate host for P. uca, and fish, the second intermediate host for S. hancocki. The increase in raccoon populations in the suburban areas surrounding west coast salt marshes could increase their importance as final hosts for trematodes in this system.

In the central nervous system of 2 raccoons, 1 cat, 1 pony, 2 mink, and 1 skunk, protozoa previously thought to be Sarcocystis-like reacted positively to Sarcocystis neurona-specific antibodies in an immunohistochemical test. In addition, S. neurona was identified in the brain of another skunk. These observations indicate that S. neurona is not confined to opossums and horses.

Antibodies to Toxoplasma gondii were found in 92 (9.9%) of 929 feral raccoons (Procyon lotor) in Japan with the use of the latex agglutination test (LAT, 1∶64 or higher). Seropositivity varied by geographic location, season, and weight of raccoons trapped. Seroprevalences in the northern, central, and western areas of Japan were found to be 7.9% (39/492), 16.5% (47/285), and 3.9% (6/152), respectively. The seroprevalence by season varied from 8.5% (13/153) in spring to 18.9% (14/74) in winter, which was significantly higher than those in other seasons (P < 0.05). Seroprevalence of T. gondii was elevated in accordance with the increase in body weight of raccoons (rs = 0.9), suggesting that the animals acquired the infection postnatally. The results suggest that the raccoon may serve as a useful indicator for the distribution of T. gondii in peridomestic environments in Japan.

The prevalence of agglutinating antibodies to Toxoplasma gondii was examined in striped skunks (Mephitis mephitis), opossums (Didelphis virginiana), and raccoons (Procyon lotor) from 8 cities in Connecticut. Ten (42%) of the 24 striped skunks, 2 of 7 (29%) opossums, and 12 of 12 (100%) raccoons were positive at dilutions of 1:50 or greater. These results suggest that T. gondii is prevalent in the environment, or prey items, or both, of these omnivores in Connecticut.

During a canine distemper virus (CDV) outbreak in raccoons (Procyon lotor) from Cook County, Illinois, a juvenile female suffering from seizures was killed and necropsied. Gross and histologic findings of necrotizing encephalitis and proliferative bronchopneumonia were attributed to CDV infection and considered the cause of clinical signs. A section of cerebellum stained immunohistochemically for Neospora caninum revealed an approximately 40 microm diameter, round to oval cyst with a 2- to 3-microm-thick wall and filled with 1-2 microm diameter, round to oval bradyzoites. Polymerase chain reaction (PCR) results were positive for N. caninum using DNA extracted from the brain. Specific PCR for the closely related organisms Toxoplasma gondii and Hammondia heydorni yielded negative results. This case report provides histologic, immunohistochemical, and molecular evidence that raccoons are a naturally occurring intermediate host of N. caninum.

Equine protozoal myeloencephalitis is the most important protozoan disease of horses in North America and is usually caused by Sarcocystis neurona. Natural and experimentally induced cases of encephalitis caused by S. neurona have been reported in raccoons (Procyon lotor) and raccoons are an intermediate host for this parasite. A 3-yr-long serological survey was conducted to determine the prevalence of agglutinating antibodies to S. neurona in raccoons collected from Fairfax County, Virginia, a suburban-urban area outside Washington, D.C. Samples from 469 raccoons were examined, and agglutinating antibodies (or = 1:50 dilution) were found in 433 (92.3%) of the raccoons. This study indicates that exposure to S. neurona is high in this metropolitan area.

Baylisascaris procyonis is the common intestinal nematode of the raccoon and is well-recognized as a cause of visceral, ocular, and neural larva migrans in many species of wild and domestic birds and mammals, including humans. To develop data on the prevalence of B. procyonis in Orange County, California, 800 distinct raccoon latrine sites were sampled in 4 spatial zones from 15 January to 31 December 2000. Counts of fecal eggs per gram (EPG) were determined and evaluated with reference to spatial zone and season of collection. No significant differences in EPG were noted among the spatial zones. However, EPG exhibited a significant rise (37,730 +/- 1,865) in the fall and a significant decline (26,204 +/- 1,446) in the winter (ANOVA, P = 0.045). The overall egg prevalence was 100%, and the overall mean EPG was 30,265 +/- 867.