Update on Baylisascariasis, a Highly Pathogenic Zoonotic Infection

Surveys on Baylisascaris procyonis in two of the three French wild raccoon populations

Human infection by Baylisascaris procyonis can result in larva migrans syndromes, which can cause severe neurological sequelae and fatal cases. The raccoon serves as the definitive host of the nematode, harboring adult worms in its intestine and excreting millions of eggs into the environment via its feces. Transmission to paratenic hosts (such as rodents, birds and rabbits) or to humans occurs by accidental ingestion of eggs. The occurrence of B. procyonis in wild raccoons has been reported in several Western European countries. In France, raccoons have currently established three separate and expanding populations as a result of at least three independent introductions. Until now the presence of B. procyonis in these French raccoon populations has not been investigated. Between 2011 and 2021, 300 raccoons were collected from both the south-western and north-eastern populations. The core parts of the south-western and north-eastern French raccoon populations were free of B. procyonis. However, three worms (molecularly confirmed) were detected in a young raccoon found at the edge of the north-eastern French raccoon population, close to the Belgian and Luxemburg borders. Population genetic structure analysis, genetic exclusion tests and factorial correspondence analysis all confirmed that the infected raccoon originated from the local genetic population, while the same three approaches showed that the worms were genetically distinct from the two nearest known populations in Germany and the Netherlands. The detection of an infected raccoon sampled east of the northeastern population raises strong questions about the routes of introduction of the roundworms. Further studies are required to test wild raccoons for the presence of B. procyonis in the area of the index case and further east towards the border with Germany.

Morphology and ASAP analysis of the important zoonotic nematode parasite Baylisascaris procyonis (Stefahski and Zarnowski, 1951), with molecular phylogenetic relationships of Baylisascaris species (Nematoda: Ascaridida)

Species of Baylisascaris (Nematoda: Ascarididae) are of great veterinary and zoonotic significance, owing to cause Baylisascariosis or Baylisascariasis in wildlife, captive animals and humans. However, the phylogenetic relationships of the current 10 Baylisascaris species remain unclear. Moreover, our current knowledge of the detailed morphology and morphometrics of the important zoonotic species B. procyonis is still insufficient. The taxonomical status of B. procyonis and B. columnaris remains under debate. In the present study, the detailed morphology of B. procyonis was studied using light and scanning electron microscopy based on newly collected specimens from the raccoon Procyon lotor (Linnaeus) in China. The results of the ASAP analysis and Bayesian inference (BI) using the 28S, ITS, cox1 and cox2 genetic markers did not support that B. procyonis and B. columnaris represent two distinct species. Integrative morphological and molecular assessment challenged the validity of B. procyonis, and suggested that B. procyonis seems to represent a synonym of B. columnaris. Molecular phylogenetic results indicated that the species of Baylisascaris were grouped into 4 clades according to their host specificity. The present study provided new insights into the taxonomic status of B. procyonis and preliminarily clarified the phylogenetic relationships of Baylisascaris species.

The Landscape of Parasitic Infections in the United States

The landscape of parasitic infections in the United States has shifted dramatically over the past century. Although infections such as malaria have been successfully eliminated, others remain endemic and pose a significant public health risk. Numerous parasitic infections are also imported each year. This article focuses on endemic parasitic infections that may be commonly seen in anatomical pathology preparations and discusses their biology, diagnostic histopathological features, and epidemiology.

Helminths in Invasive Raccoons (Procyon lotor) from Southwest Germany

As hosts of numerous zoonotic pathogens, the role of raccoons needs to be considered in the One Health context. Raccoons progressively expand their range as invasive alien species in Europe. This study aimed to investigate the intestinal helminth fauna of raccoons in Baden-Wuerttemberg, Germany, as no such screening had ever been conducted there. In total, we obtained 102 animals from hunters in 2019 and 2020. Intestinal helminths were retrieved using the SSCT (segmented sedimentation and counting technique) and identified morphologically and by PCR-based Sanger sequencing. Fecal samples were assessed using the ELISA PetChek^TM IP assay (IDEXX, Germany) and flotation technique. The artificial digestion method was employed for analyzing muscle tissue. We detected species of four nematode genera (Baylisascaris procyonis, Toxocara canis, Capillaria spp., and Trichuris spp.), three cestode genera (Atriotaenia cf. incisa/procyonis, Taenia martis, and Mesocestoides spp.), and three trematode genera (Isthmiophora hortensis/melis, Plagiorchis muris, and Brachylaima spp.). Echinococcus spp. and Trichinella spp. were not found. The invasive behavior and synanthropic habits of raccoons may increase the infection risk with these helminths in wildlife, domestic and zoo animals, and humans by serving as a connecting link. Therefore, it is crucial to initiate additional studies assessing these risks.

Baylisascaris procyonis Roundworm Infection in Child with Autism Spectrum Disorder, Washington, USA, 2022

We describe a case of Baylisascaris procyonis roundworm infection in a child in Washington, USA, with autism spectrum disorder. Environmental assessment confirmed nearby raccoon habitation and B. procyonis eggs. B. procyonis infections should be considered a potential cause of human eosinophilic meningitis, particularly among young children and persons with developmental delays.

Detection of Endoparasites in Non-Native Raccoons from Central Italy

The raccoon (Procyon lotor) is a carnivore native to North and Central America, gradually introduced into Asia and Europe, including Italy. It is an important carrier of multiple endoparasites, both Protozoa and Helminths, some of them being zoonotic. The aim of this study was to investigate the endoparasites of the non-native raccoon population of Central Italy. Sixty-two raccoons were collected by local competent authorities (sixty trapped and euthanized, two found dead) and subjected to necroscopic examination. Carcasses underwent a broad parasitological investigation, including coprological techniques (macroscopic examination of the gastrointestinal tract, lungs, trachea, and heart, Flotac^®, Baermann test, and immunofluorescence for Giardia duodenalis and Cryptosporidium spp.), research on respiratory/urinary capillariosis and artificial digestion for Trichinella spp. larvae, and a histopathological examination of the ileum. Ascarid parasites were further identified at the species level using a next-generation sequencing-based amplicon sequencing approach. The results showed the presence of different Protozoa and Nematodes: Baylisascaris procyonis (26/62; 41.9%), Pearsonema sp. (6/62; 9.6%), Capillariidae (6/62; 9.6%), Eimeria sp. (2/62; 3.2%), Cryptosporidium sp. (2/62; 3.2%), and Ancylostomatidae (2/62; 3.2%). B. procyonis is an emerging helminthic zoonotic agent considered a serious concern for public and animal health, given the possibility of its transmission to paratenic hosts, including humans and pets. The demonstrated role of the raccoon as a multi-parasite carrier should be an incentive to continuing the eradication/control of this alien species, and supports the need to implement related disease surveillance programs.

Raccoons contraband - The metazoan parasite fauna of free-ranging raccoons in central Europe

The invasive raccoon (Procyon lotor) is an abundant carnivore and considered as an important potential vector of infectious diseases and parasites in Europe. Raccoons show a broad, opportunistic, omnivorous food spectrum. Food supply and habitat quality in urban areas are very attractive for the generalist raccoon. This inevitably leads to increased interaction with humans, domestic animals and livestock, making the raccoon a potentially suitable zoonosis vector. In its autochthonous range, especially in the Eastern and Midwestern United States, the raccoon has been studied very intensively since the beginning of the 20th century. Whereas, basic field biology and parasitology studies in Germany and Europe are lacking and have only been conducted sporadically, regionally and on small sample sizes. In the presented study 234 raccoons from central Germany were comprehensively examined for their metazoan parasite fauna. The present study shows for the first time an extremely diverse parasite fauna in raccoons outside their native range and proves their essential role as intermediate hosts and hosts for ecto- and endoparasites. A total of 23 different parasite species were identified, five of which are human pathogens, 14 of which are new for the parasite fauna of raccoons in Europe. The human pathogenic raccoon roundworm Baylisascaris procyonis is the most common parasite species in this study, with a prevalence of up to 95%. The digenetic trematode Plagiorchis muris, another human pathogenic parasite species, was detected for the first time in raccoons. The ongoing spread of invasive carnivores and the associated spread and transmission of their parasites and other pathogens increases the potential health risk of wild and farmed animals as well as humans. An increase in parasitic diseases in humans (e.g. raccoon roundworm) is to be expected, especially in urban areas, where raccoons are becoming more and more abundant.

Eosinophilic Meningitis: Eleven-Year Experience at Texas Children's Hospital

Eosinophilic meningitis can be caused by various etiologies and is reported mostly in tropical climates. The diagnosis is rare in the continental US, presenting challenges for management. Following a case of pediatric eosinophilic meningitis, we reviewed our 11-year experience with this diagnosis at a large US children's hospital.

Potentials and challenges in the isolation and detection of ascarid eggs in complex environmental matrices

Ascarid infections constitute a major concern for both human and animal health risk assessment. Although being effectively transmitted by soil, water and contaminated food, reliable detection of ascarid eggs in environmental media often remains challenging. However, contamination of the environment with ascarid ova has gained more attention as a decisive part of proper risk assessment in recent years. Due to various factors, such as sample matrices, dissociation detergents and flotation solutions, defined and standardised protocols for the isolation of eggs from complex environmental matrices are difficult to establish and therefore limited. Thus, this study reviews common techniques used for the recovery of ascarid eggs from environmental media with special emphasis on sampling strategies, purification procedures and microscopic as well as molecular detection of egg contamination. Despite various advancements, mainly in the field of molecular methods leading to more reliable and sensitive detection, it can be concluded that there is still a need for unified guidelines for sampling and recovery of ascarid eggs derived from complex environmental matrices.

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Standardised methods to assess environmental ascarid egg contamination are needed.

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The environmental sampling strategy has to be adapted to the study hypothesis.

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Egg detection mostly relies on matrix homogenisation, filtration, sedimentation and flotation.

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Microscopic detection is still frequently applied.

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Molecular methods enable more reliable and sensitive detection.

A Worm’s Tale or Why to Avoid the Raccoon Latrine: A Case of Baylisascaris procyonis Meningoencephalitis

The raccoon roundworm Baylisascaris procyonis (B. procyonis) may infect humans to cause severe or fatal meningoencephalitis, as well as ocular and visceral larva migrans. Young children are at greater risk for cerebral larva migrans with severe meningoencephalitis, and early empiric therapy may improve outcomes. Familiarity with characteristic brain imaging findings may prompt earlier diagnosis, particularly in the setting of CSF eosinophilia. We report a case of a 19-month-old boy who presented with truncal ataxia and was found to have peripheral and CSF eosinophilia. MRI demonstrated symmetric, confluent T2 hyperintense signal in the cerebral and cerebellar deep white mater, which helped differentiate B. procyonis meningoencephalitis from other infectious and non-infectious causes of eosinophilic meningoencephalitis. Early recognition and treatment of B. procyonis meningoencephalitis are important for improved outcomes, and careful review of neuroimaging can play a critical role in suggesting the diagnosis.

Is it canine DUSN?: Another view of retinopathies, some acquired, and others possibly "inherited": Another view of retinopathies, some acquired, and others possibly "inherited"

The term retinopathy has been used to group several heterogeneous retinal abnormalities that are clearly acquired or are suspected/proposed to be inherited. Some share characteristic focal/multifocal hyperreflective tapetal lesions with a dark center, and areas of non-tapetal depigmentation suggestive of patchy or diffuse outer retinal atrophy. Progression is variable, and some develop unilateral or bilateral fundus changes resembling the clearly inherited form of retinal degeneration referred to as PRA. In this Commentary and Review, we discuss the role of ocular larva migrans resulting in the entity we refer to as canine DUSN and suggest that it may be responsible for some of the retinal findings grouped under the retinopathy rubric that share this characteristic fundus lesion.

First report of the zoonotic nematode Baylisascaris procyonis in non-native raccoons (Procyon lotor) from Italy

Baylisascaris procyonis is a nematode parasite of the raccoon (Procyon lotor), and it can be responsible for a severe form of larva migrans in humans. This parasite has been reported from many countries all over the world, after translocation of its natural host outside its native geographic range, North America. In the period between January and August 2021, 21 raccoons were cage-trapped and euthanized in Tuscany (Central Italy), in the context of a plan aimed at eradicating a reproductive population of this non-native species. All the animals were submitted for necroscopic examination. Adult ascariids were found in the small intestine of seven raccoons (prevalence 33.3%). Parasites have been identified as B. procyonis based on both morphometric and molecular approaches. The aim of the present article is to report the first finding of this zoonotic parasite from Italy, highlighting the sanitary risks linked to the introduction of alien vertebrate species in new areas.

Canine and Feline Parasitology: Analogies, Differences, and Relevance for Human Health

Cats and dogs are treated as family members by most pet owners. Therefore, a high quality of veterinary care and preventive medicine is imperative for animal health and welfare and for the protection of humans from zoonotic pathogens. There is a general perception of cats being treated as "small dogs," especially in the field of clinical parasitology. As a result, several important differences between the two animal species are not taken into proper consideration and are often overlooked. Dogs and cats are profoundly different under evolutionary, biological, ethological, behavioral, and immunological standpoints. These differences impact clinical features, diagnosis, and control of canine and feline parasites and transmission risk for humans. This review outlines the most common parasitoses and vector-borne diseases of dogs and cats, with a focus on major convergences and divergences, and discusses parasites that have (i) evolved based on different preys for dogs and cats, (ii) adapted due to different immunological or behavioral animal profiles, and (iii) developed more similarities than differences in canine and feline infections and associated diseases. Differences, similarities, and peculiarities of canine and feline parasitology are herein reviewed in three macrosections: (i) carnivorism, vegetarianism, anatomy, genetics, and parasites, (ii) evolutionary adaptation of nematodes, including veterinary reconsideration and zoonotic importance, and (iii) behavior and immune system driving ectoparasites and transmitted diseases. Emphasis is given to provide further steps toward a more accurate evaluation of canine and feline parasitology in a changing world in terms of public health relevance and One Health approach.

An outbreak of canine schistosomiasis in Utah: Acquisition of a new snail host (Galba humilis) by Heterobilharzia americana, a pathogenic parasite on the move

Parasites with complex life cycles engaging multiple host species living among different environments well-exemplify the value of a cross-cutting One Health approach to understanding fundamental concerns like disease emergence or spread. Here we provide new information regarding a pathogenic schistosome trematode parasite of both wild and domestic mammals that has recently expanded its known range from mesic/wet environments of the southeastern United States to the arid southwest. In 2018, 12 dogs living near a man-made pond in Moab, Utah, were found positive for Heterobilharzia americana, the most westerly report of this endemic North American schistosome, and the first from Utah. Raccoon scats collected near the pond were positive for H. americana eggs, and snails living near the pond's water line identified as Galba humilis shed H. americana cercariae, the first indication of natural infections in this widespread North American snail species. The susceptibility of G. humilis to H. americana was confirmed experimentally. Our studies support the existence of two variants of H. americana and emphasize the need for further investigations of lymnaeids and their compatibility with H. americana, to better define the future potential for its spread. Capture of a new species of intermediate host vector snail and construction of man-made habitats suitable for this snail have created the potential for a much more widespread animal health problem, especially for dogs and horses. H. americana will prove difficult to control because of the role of raccoons in maintaining transmission and the amphibious habits of the snail hosts of this pathogenic schistosome.

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The pathogenic canine schistosome Heterobilharzia americana expands its known range.

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First evidence of new snail vector, Galba humilis.

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Galba humilis is widely distributed in North America, enabling further spread.

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Raccoons are also important hosts and their increasing abundance also favors spread.

Practical Guidance for Clinical Microbiology Laboratories: Diagnosis of Ocular Infections

The variety and complexity of ocular infections have increased significantly in the last decade since the publication of Cumitech 13B, Laboratory Diagnosis of Ocular Infections (L. D. Gray, P. H. Gilligan, and W. C. Fowler, Cumitech 13B, Laboratory Diagnosis of Ocular Infections, 2010). The purpose of this practical guidance document is to review, for individuals working in clinical microbiology laboratories, current tools used in the laboratory diagnosis of ocular infections. This document begins by describing the complex, delicate anatomy of the eye, which often leads to limitations in specimen quantity, requiring a close working bond between laboratorians and ophthalmologists to ensure high-quality diagnostic care. Descriptions are provided of common ocular infections in developed nations and neglected ocular infections seen in developing nations. Subsequently, preanalytic, analytic, and postanalytic aspects of laboratory diagnosis and antimicrobial susceptibility testing are explored in depth.

PHYLOGEOGRAPHY OF BAYLISASCARIS PROCYONIS (RACCOON ROUNDWORM) IN NORTH AMERICA

Sequences of the mitochondrial cytochrome c oxidase 1 (COI) gene of 115 Baylisascaris procyonis individuals from 13 U.S. states and 1 Canadian province were obtained from 44 raccoon hosts to assess genetic variation and geographic structure. The maximum genetic distance between individuals was low (1.6%), consistent with a single species. Moderate COI haplotype (h = 0.60) and nucleotide (π = 0.0053) diversity were found overall. Low haplotype diversity was found among samples east of the Mississippi River (h = 0.036), suggesting that historical growth and expansion of raccoon populations in this region could be responsible for high parasite gene flow or a selective sweep of B. procyonis mtDNA. There was low genetic structure (average Φst = 0.07) for samples east of the continental divide, but samples from Colorado showed higher diversity and differentiation from midwestern and eastern samples. There was marked genetic structure between samples from east and west of the continental divide, with no haplotypes shared between these regions. There was no significant isolation by distance among any of these geographic samples. The phylogeographic patterns for B. procyonis are similar to genetic results reported for their raccoon definitive hosts. The phylogeographic divergence of B. procyonis from east and west of the continental divide may involve vicariance resulting from Pleistocene glaciation and associated climate variation.

Lost and found: Helminths infecting invasive raccoons introduced to Italy

North American raccoons (Procyon lotor) have been introduced to several European countries, where they may represent a sanitary threat as hosts of several pathogens such as the zoonotic ascarid Baylisascaris procyonis. We carried out parasitological analysis on raccoons introduced to Italy to verify whether the species had carried along B. procyonis or any other gastro-intestinal helminths that may threaten humans, livestock or native wildlife. We examined 64 raccoons culled in Northern Italy during control activities and 3 roadkills opportunistically sampled from a separate population located in central Italy. Helminths were collected from the gastro-intestinal tract through standard parasitological techniques and identified based on a combination of morphology and molecular methods. Overall, examined raccoons showed a poor parasitic fauna, with almost 30% of individuals free of any helminth infection. The most prevalent species were the nematodes Strongyloides procyonis (26.9%), Aonchotheca putorii (25.4%) and Porrocaecum sp. (19.4%). Plagiorchis sp. trematodes were also common (13.4%), whereas cestodes were scarcely represented. With the exception of S. procyonis introduced from North America, all the other identified taxa have either a Eurasian or a wide Holarctic distribution. Despite not finding any B. procyonis in the examined raccoons, passive surveillance for this parasite should be implemented, especially in Tuscany, since the limited host sample examined in the present survey does not allow to exclude its presence.

[Unilateral optic atrophy in a 9-year-old patient]

Ein 9‑jähriger Patient stellte sich aufgrund einer seit 2 Wochen zufällig bemerkten Sehminderung auf dem linken Auge vor. Funduskopisch waren neben einer leichten Vitritis eine blasse Papille, enggestellte Gefäße und eine Reflexvermehrung der Netzhautoberfläche sichtbar. In der Blutuntersuchung waren die Werte bis auf eine Eosinophilie und einen erhöhten Immunglobublin E(IgE)-Antikörpertiter normal.

The morphological and molecular characterization of Baylisascaris devosi Sprent, 1952 (Ascaridoidea, Nematoda), collected from Pine marten (Martes martes) in Iran

Background

Baylisascaris devosi is an intestinal nematode found in several carnivores including fisher, wolverine, Beech marten, American marten and sable in different parts of the world, but this nematode has not been reported from Pine marten. Therefore, this study aimed to identify Baylisascaris isolated from a Pine marten in Iran using morphological and molecular approaches.

Methods

Specimens of B. devosi were collected from one road-killed Pine marten in northern Iran. Morphological features were evaluated using scanning electron microscopy, energy dispersive x-ray analysis and ion sectioning. The molecular characterization was carried out using partial Cox1, LSU rDNA and ITS-rDNA genes.

Results

The nematodes isolated from the Pine marten were confirmed to be B. devosi based on the morphological features and the sequence of ribosomal and mitochondrial loci. X-ray scans (EDAX) were completed on gallium cut structures (papillae, eggs, male spike and mouth denticles) of B. devosi using a dual-beam scanning electron microscope. The male spike and mouth denticles had a high level of hardening elements (Ca, P, S), helping to explain the chemical nature and morphology of the worm. Based on these genetic marker analyses, our sequence had the greatest similarity with Russian B. devosi isolated from sable.

Conclusions

In this study, to our knowledge, the occurrence of B. devosi infection in Pine marten is reported for the first time. Molecular analysis showed that these three genes are suitable molecular markers for identification and inferring phylogenetic relationships of Baylisascaris species. Furthermore, the high divergence of Cox1 between Baylisascaris species indicates that Cox1 could be used for their phylogenetic and taxonomic studies.

A potential zoonotic threat: First detection of Baylisascaris procyonis in a wild raccoon from Austria

Baylisascaris procyonis is a common gastrointestinal parasite of raccoons (Procyon lotor) in their native range, and both have been introduced to Europe. Humans may ingest ascarid eggs shed via the racoons’ faeces, and this could lead to severe infections affecting the central nervous system. Here, we report the first occurrence of B. procyonis in Austria. The parasite was detected in a two‐year‐old male raccoon that was road‐killed in November 2019 near Hittisau (Vorarlberg). Genetic profiling provided strong evidence that the raccoon (and its parasite) originated from the nearest German raccoon population. The first finding in Austria highlights the need for monitoring the parasite and information of the public and practitioners.

The Control of Zoonotic Soil-Transmitted Helminthoses Using Saprophytic Fungi

Soil-transmitted helminths (STHs) are parasites transmitted through contact with soil contaminated with their infective eggs/larvae. People are infected by exposure to human-specific species or animal species (zoonotic agents). Fecal samples containing eggs of Ascaris suum or Lemurostrongylus sp. were sprayed with spores of the soil saprophytic filamentous fungi Clonostachys rosea (CR) and Trichoderma atrobrunneum (TA). The antagonistic effect was assessed by estimating the viability of eggs and their developmental rate. Compared to the controls (unexposed to fungi), the viability of the eggs of A. suum was halved in CR and decreased by two thirds in TA, while the viability of the eggs of Lemurostrongylus sp. was reduced by one quarter and one third in CR and TA treatments, respectively. The Soil Contamination Index (SCI), defined as the viable eggs that attained the infective stage, reached the highest percentages for A. suum in the controls after four weeks (66%), with 21% in CL and 11% in TA. For Lemurostrongylus sp., the values were 80%, 49%, and 41% for control, CR and TA treatments, respectively. We concluded that spreading spores of C. rosea or T. atrobrunneum directly onto the feces of animal species represents a sustainable approach under a One Health context to potentially reduce the risk of zoonotic STHs in humans.

Spatio-temporal clustering of Baylisascaris procyonis, a zoonotic parasite, in raccoons across different landscapes in southern Ontario

Baylisascaris procyonis, the raccoon roundworm, is a parasite found throughout North America and parts of Europe. More than 150 species of mammals and birds including humans can develop neurological disease following infection with the larval stage of this parasite. To investigate whether B. procyonis infections in raccoons cluster in space, time, or space-time, we used data from 1353 Ontario raccoons submitted to the Canadian Wildlife Health Cooperative between 2013 and 2016. We identified a significant spatial cluster of increased infection prevalence in southern Ontario centered over a major metropolitan area, as well as a significant cluster of decreased infection prevalence in a primarily agricultural region in southwestern Ontario. Furthermore, we identified statistically significant temporal clusters in the fall in annual scans of data from 2014, 2015 and 2016. Examination of both Bernoulli and space-time permutation models for space-time analysis suggested that the purely spatial and temporal clusters were not explained by relatively short and spatially discrete events in space-time. The identified annual temporal clusters are consistent with previous research on the seasonality of B. procyonis infection in raccoons. Recognition of the spatial infection clusters will help identify potential geographic and anthropogenic factors associated with the occurrence of B. procyonis infection in raccoons. Given the zoonotic potential of this parasite, identification of a cluster of high infection prevalence in a major metropolitan area has implications for public education and risk management strategies.

Raccoon roundworm prevalence (Baylisascaris procyonis) at the North Carolina Zoo, USA

Baylisascaris procyonis is an important zoonotic nematode of raccoons (Procyon lotor). Infection with this parasite has important health implications for humans, zoo animals, and free-ranging wildlife. As a large, natural habitat zoo, the North Carolina Zoo (NC Zoo) coexists with native wildlife. Raccoons are abundant at the NC Zoo and the prevalence of B. procyonis is unknown. Raccoon latrines were located through employee reporting and systematic searching throughout the zoo and sampled for B. procyonis in October and November of 2018 and 2019. Parasite prevalence, latrine location, substrate category and latrine persistence were recorded. Thirty-three latrines were located in 2018 and eight new latrines in 2019 while four latrines from the prior year were no longer available to be sampled. Of the 29 latrines sampled over the two years, 16 (55%) persisted for at least one year. The majority of the latrines were found on natural substrate with rock showing the highest preference. Just over half (n = 21 of 41 total) of the active latrines in the study were in or immediately adjacent to animal enclosures. Two latrines were found in public areas including one contaminating children’s play equipment. Additionally, fresh fecal samples were collected from five adult raccoons presented to the zoo’s veterinary clinic in 2018 and 2019. All fecal samples tested by centrifugal flotation for both years were negative for B. procyonis. The results of this study show the value of field sampling to properly assess risk and enable informed decision-making regarding public health and wildlife management.

Detection of DNA from the zoonotic raccoon roundworm Baylisascaris procyonis in a French wolf

Baylisascaris procyonis is a zoonotic nematode whose main definitive host is the raccoon, an invasive carnivore in Europe introduced from the United States. B. procyonis causes larva migrans with poor prognosis in humans. This parasite was unexpectedly detected in France for the first time upon molecular screening of wolf faecal samples. Because no patent infection was found, the wolf cannot be considered as a definitive host. This discovery of B. procyonis in France nonetheless raises questions about the parasite status of the expanding raccoon populations in the country, which will be investigated in the future.

Prevalence of Baylisascaris procyonis in Raccoons Trapped in New Orleans, Louisiana, 2014-2017

Baylisascaris procyonis, the raccoon roundworm, is considered an emerging zoonotic disease in the United States after being identified in raccoons captured in different US regions and metropolitan areas. Humans can become infected with B. procyonis after ingesting mature roundworm eggs, sometimes resulting in fatal disease or severe sequelae in these patients. The first reported human Baylisascaris case in New Orleans raised concerns that very little was known about this zoonotic disease in the increasing urban raccoon population. Therefore, the study aim was to estimate the prevalence of Baylisascaris-infected raccoons in New Orleans, LA. Raccoons were trapped based on nuisance calls from the public and in areas where raccoons had been sighted. Necropsies were performed to identify B. procyonis adult worms in intestines and fecal samples were examined for roundworm ova. Study findings showed that 38.5% of New Orleans raccoons were infected with B. procyonis, defined by the presence of adult B. procyonis worms or Baylisascaris ova in their feces. Twenty-four of 65 raccoons (36.9%) had raccoon roundworms in their intestines and 31.7% of the fecal samples were positive for B. procyonis eggs. Mapping B. procyonis-infected raccoons by trapping location showed that infected raccoons were found throughout the city. In conclusion, the high prevalence rate of B. procyonis in New Orleans raccoons demonstrates the importance of educating the public and health care professionals about potential health risks and providing resources to prevent exposure to infective eggs from raccoon latrines. Furthermore, this emerging disease should be further studied to examine human risk of infection in increasing raccoon populations in metropolitan areas.

Baylisascariasis: A young boy with neural larva migrans due to the emerging raccoon round worm

A 17-month-old boy from Vancouver, Canada, presented with a 5-day history of progressive somnolence, ataxia, and torticollis. Additional investigations revealed eosinophilic encephalitis with deep white matter changes on MR imaging. On day 13, serology came back positive for Baylisascaris procyonis antibodies. While prophylaxis after ingestion of soil or materials potentially contaminated with raccoon feces can prevent baylisascariasis, timely treatment can sometimes alter a disastrous outcome. Populations of infected raccoons are propagating globally, but cases of Baylisascaris neural larva migrans have so far only been reported from North America.

Baylisascaris procyonis infection in raccoons: A review of demographic and environmental factors influencing parasite carriage

Baylisascaris procyonis, the roundworm of raccoons (Procyon lotor), is an emerging helminthic zoonosis in North America. Since the larval form is capable of causing neurological disease in more than 150 species of birds and mammals including humans, understanding factors that influence carriage of the parasite by raccoons is important for mitigating risk. This review examines the current literature to identify major demographic and environmental risk factors associated with B. procyonis carriage in wild raccoons. Raccoon age and season of sample collection were most commonly identified as risk factors, with increased prevalence found in juvenile animals and when sample collection occurred in the fall. Human urbanization and agricultural land use were also observed as potential risk factors; however, there are inconsistencies in the direction of influence these risk factors have on the prevalence of infection. Further investigation into the role of environmental risk factors is required to better understand how human activities influence parasite carriage in raccoons. Additionally, future research using multivariable statistical models guided by epidemiological principles to control for confounding variables and identify interaction effects will help clarify the effect of these demographic and environmental factors. Developing a better understanding of the primary risk factors for parasite carriage in raccoons will help identify areas of higher risk for environmental contamination and will aid in the development and refinement of education and management programs to reduce the risk of human exposure.

Neurologic Baylisascaris procyonis infection in a young dog

A 14-week-old female Boston terrier-cross dog with intermittent gastroenteritis and an eosinophilia developed progressive neurologic disease with ataxia progressing to uncontrolled paddling. Autopsy revealed Baylisascaris procyonis larvae in 4 of 7 brain sections, with severe eosinophilic meningoencephalitis. Diagnosis was confirmed with polymerase chain reaction (PCR) and DNA sequencing tests of fresh and paraffin-embedded brain in conjunction with the compatible histologic appearance.

Molecular phylogenetics and species-level systematics of Baylisascaris

Nucleotide sequences representing nine genes and five presumptive genetic loci were used to infer phylogenetic relationships among seven Baylisascaris species, including one species with no previously available molecular data. These genes were used to test the species status of B. procyonis and B. columnaris using a coalescent approach. Phylogenetic analysis based on combined analysis of sequence data strongly supported monophyly of the genus and separated the species into two main clades. Clade 1 included B. procyonis, B. columnaris, and B. devosi, species hosted by musteloid carnivores. Clade 2 included B. transfuga and B. schroederi from ursids, B. ailuri, a species from the red panda (a musteloid), and B. tasmaniensis from a marsupial. Within clade 2, geographic isolates of B. transfuga, B. schroederi (from giant panda), and B. ailuri formed a strongly supported clade. In certain analyses (e.g., some single genes), B. tasmaniensis was sister to all other Baylisascaris species rather than sister to the species from ursids and red panda. Using one combination of priors corresponding to moderate population size and shallow genetic divergence, the multispecies coalescent analysis of B. procyonis and B. columnaris yielded moderate support (posterior probability 0.91) for these taxa as separate species. However, other prior combinations yielded weak or no support for delimiting these taxa as separate species. Similarly, tree topologies constrained to represent reciprocal monophyly of B. columnaris and B. procyonis individuals (topologies consistent with separate species) were significantly worse in some cases, but not others, depending on the dataset analyzed. An expanded analysis of SNPs and other genetic markers that were previously suggested to distinguish between individuals of B. procyonis and B. columnaris was made by characterization of additional individual nematodes. The results suggest that many of these SNPs do not represent fixed differences between nematodes derived from raccoon and skunk hosts.

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A phylogenetic hypothesis for Baylisascaris species was produced using nine genes.

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Genetic data was generated for two new species- B. devosi and B. tasmaniensis.

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Baylisascaris devosi and B. tasmaniensis were part of a monophyletic Baylisascaris.

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B. procyonis (raccoon) and B. columnaris (skunk) could not be reliably distinguished.

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Established SNPs may not be diagnostic for Baylisascaris from raccoons and skunks.

Seroprevalence of Baylisascaris procyonis Infection among Humans, Santa Barbara County, California, USA, 2014-2016

Baylisascaris procyonis (raccoon roundworm) infection is common in raccoons and can cause devastating pathology in other animals, including humans. Limited information is available on the frequency of asymptomatic human infection. We tested 150 adults from California, USA, for B. procyonis antibodies; 11 were seropositive, suggesting that subclinical infection does occur.

Parasites of the Giant Panda: A Risk Factor in the Conservation of a Species

The giant panda, with an estimated population size of 2239 in the world (in 2015), is a global symbol of wildlife conservation that is threatened by habitat loss, poor reproduction and limited resistance to some infectious diseases. Of these factors, some diseases caused by parasites are considered as the foremost threat to its conservation. However, there is surprisingly little published information on the parasites of the giant panda, most of which has been disseminated in the Chinese literature. Herein, we review all peer-reviewed publications (in English or Chinese language) and governmental documents for information on parasites of the giant pandas, with an emphasis on the intestinal nematode Baylisascaris schroederi (McIntosh, 1939) as it dominates published literature. The purpose of this chapter is to: (i) review the parasites recorded in the giant panda and describe what is known about their biology; (ii) discuss key aspects of the pathogenesis, diagnosis, treatment and control of key parasites that are reported to cause clinical problems and (iii) conclude by making some suggestions for future research. This chapter shows that we are only just 'scratching the surface' when it comes to parasites and parasitological research of the giant panda. Clearly, there needs to be a concerted research effort to support the conservation of this iconic species.

Raccoon roundworm (Baylisascaris procyonis) as an occupational hazard: 1. Knowledge of B. procyonis and attitudes towards it and other zoonoses among wildlife rehabilitators

Wildlife rehabilitators are at risk of zoonotic diseases because they often have prolonged contact with many species of wildlife and their bodily fluids. Raccoon roundworm (Baylisascaris procyonis) is a common zoonotic parasite of raccoons that has the potential to cause severe or fatal neurologic disease in a broad variety of hosts if the eggs within raccoon faeces are ingested. We administered an online survey to wildlife rehabilitators to assess their knowledge regarding aspects of transmission, biology and disease caused by B. procyonis, and also to evaluate attitudes towards wildlife diseases and B. procyonis as an occupational hazard. Knowledge was assessed using multiple choice and true-false questions; attitudes were measured using Likert-type items. A total of 659 complete or near-complete responses (missing fewer than three knowledge or attitudes items and/or non-response to some demographic fields) were collected. The median knowledge score was 7/14 questions correct (range: 0-14 correct). Generally, individuals with higher levels of education and rehabilitation experience, veterinary professionals and those who are members of professional wildlife rehabilitation groups scored above the median significantly more often (p < .01). Significantly more rehabilitators who were located in the south-east and those with part-time or infrequent commitments scored below the median overall knowledge score. There was general agreement that B. procyonis is a health risk of rehabilitators and that measures should be taken to control transmission to people and animals. Some factors explaining differences in attitudes include setting of rehabilitation (home versus animal care facility), veterinary profession, region, membership in a wildlife rehabilitation group and rehabilitation of raccoons. Findings emphasize the importance of awareness and mentorship to inform rehabilitators on the potential risks of B. procyonis and other potential zoonoses within captive wildlife settings, and the important role of professional wildlife rehabilitator groups in disseminating educational materials.

Baylisascaris procyonis roundworm infection patterns in raccoons (Procyon lotor) from Missouri and Arkansas, USA

Baylisascaris procyonis is a helminth parasite of raccoons Procyon lotor and represents a health concern in paratenic hosts, including humans and diverse domestic and wildlife species. In North America the helminth is expanding its geographic range. To better understand patterns of infection in the Ozark region of the USA, raccoons (n = 61) were collected in 2013-2014 from five counties in Missouri and Arkansas, USA and necropsied. We documented B. procyonis in all surveyed locations. The overall prevalence of B. procyonis was 44.3 % (95 % CI = 31.9 - 57.4) and was significantly higher in females than males. There were also significant differences in prevalence among raccoons sampled north and south of the Missouri River. Mean intensity was 9.9 (CI = 5.44 - 17.22), and parasites were highly aggregated among hosts such that approximately 20 % of hosts harbor 90 % of parasites. These levels of parasitism indicate that B. procyonis is common in the region and its impacts on paratenic hosts could be qualitatively similar to effects observed in other localities.

Partial molecular characterization of the mitochondrial genome of Baylisascaris columnaris and prevalence of infection in a wild population of Striped skunks

Members of the genus Baylisascaris utilize omnivores or carnivores as their definitive hosts. The best known member of this genus is Baylisascaris procyonis, which is an intestinal parasite of raccoons. The closest relative of B. procyonis is B. columnaris, which utilizes the common skunk as its definitive host. Although B. procyonis has been extensively studied, relatively little is known of B. columnaris. For example, the mitochondrial genome of B. procyonis has been sequenced in its entirety. Conversely, the mitochondrial genome of B. columnaris remains largely unexplored. Likewise, the prevalence of this parasite in its wild host has not been documented. In this study, we collected parasites from a wild population of skunks in the state of Utah, United States. The cytochrome c oxidase subunit 1 and 2 genes, NADH dehydrogenase 2 and several tRNA genes were sequenced from the mitochondrial genome of these parasites. We also determined the prevalence of B. columnaris in a wild population of skunks. In this work we identify several novel polymorphic genetic loci between B. procyonis and B. columnaris. These findings provide additional molecular targets for the differentiation of Baylisascaris species through clarification of genetic differences between B. columnaris and B. procyonis.

Raccoon Roundworm Infection Associated with Central Nervous System Disease and Ocular Disease - Six States, 2013-2015

Baylisascaris procyonis, predominantly found in raccoons, is a ubiquitous roundworm found throughout North America. Although raccoons are typically asymptomatic when infected with the parasite, the larval form of Baylisascaris procyonis can result in fatal human disease or severe neurologic outcomes if not treated rapidly. In the United States, Baylisascaris procyonis is more commonly enzootic in raccoons in the midwestern and northeastern regions and along the West Coast (1). However, since 2002, infections have been documented in other states (Florida and Georgia) and regions (2). Baylisascariasis is not a nationally notifiable disease in the United States, and little is known about how commonly it occurs or the range of clinical disease in humans. Case reports of seven human baylisascariasis cases in the United States diagnosed by Baylisascaris procyonis immunoblot testing at CDC are described, including review of clinical history and laboratory data. Although all seven patients survived, approximately half were left with severe neurologic deficits. Prevention through close monitoring of children at play, frequent handwashing, and clearing of raccoon latrines (communal sites where raccoons defecate) are critical interventions in curbing Baylisascaris infections. Early treatment of suspected cases is critical to prevent permanent sequelae.