EVALUATION OF ANTHELMINTIC FISHMEAL POLYMER BAITS FOR THE CONTROL OF BAYLISASCARIS PROCYONIS IN FREE-RANGING RACCOONS ( PROCYON LOTOR )

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.

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.

BAIT DEVELOPMENT FOR ORAL DELIVERY OF PHARMACEUTICALS TO RACCOONS (PROCYON LOTOR) AND STRIPED SKUNKS (MEPHITIS MEPHITIS)

Oral vaccination is one tool used to control wildlife diseases. A challenge to oral vaccination is identifying baits specific to target species. The US has been conducting oral vaccination against rabies since the 1990s. Improvements in bait development will hasten disease elimination. In Colorado, we examined a novel bait for oral vaccination and offered two different flavors, sweet and fish, to captive raccoons ( Procyon lotor ) and striped skunks ( Mephitis mephitis ) to assess consumption and flavor preference and observed bait removal by target and nontarget species in the field. During captive trials, raccoons and skunks consumed 98% and 87% of offered baits, respectively. Baits contained a sachet to simulate a vaccine package. Raccoons and skunks consumed 98% and 94% of the sachets, respectively. All unconsumed sachets were punctured, suggesting that animals had oral exposure to the contents. Raccoons preferred fish-flavored bait, but skunks did not have a preference. In the field, raccoons consumed the most baits, followed by fox squirrels ( Sciurus niger ). Other rabies host species (striped skunks, red foxes [ Vulpes vulpes ], coyotes [ Canis latrans ]) had very low visitation and were never observed consuming baits. High consumption rates by raccoons and skunks in captivity and observance of raccoons consuming baits in the field suggest that these baits may be useful for oral delivery of pharmaceuticals. Further field research is warranted to determine how to best optimize bait delivery.

Update on Baylisascariasis, a Highly Pathogenic Zoonotic Infection

Baylisascaris procyonis, the raccoon roundworm, infects a wide range of vertebrate animals, including humans, in which it causes a particularly severe type of larva migrans. It is an important cause of severe neurologic disease (neural larva migrans [NLM]) but also causes ocular disease (OLM; diffuse unilateral subacute neuroretinitis [DUSN]), visceral larva migrans (VLM), and covert/asymptomatic infections. B. procyonis is common and widespread in raccoons, and there is increasing recognition of human disease, making a clinical consideration of baylisascariasis important. This review provides an update for this disease, especially its clinical relevance and diagnosis, and summarizes the clinical cases of human NLM and VLM known to date. Most diagnosed patients have been young children less than 2 years of age, although the number of older patients diagnosed in recent years has been increasing. The recent development of recombinant antigen-based serodiagnostic assays has aided greatly in the early diagnosis of this infection. Patients recovering with fewer severe sequelae have been reported in recent years, reinforcing the current recommendation that early treatment with albendazole and corticosteroids should be initiated at the earliest suspicion of baylisascariasis. Considering the seriousness of this zoonotic infection, greater public and medical awareness is critical for the prevention and early treatment of human cases.

The Increase of Exotic Zoonotic Helminth Infections: The Impact of Urbanization, Climate Change and Globalization

Zoonotic parasitic diseases are increasingly impacting human populations due to the effects of globalization, urbanization and climate change. Here we review the recent literature on the most important helminth zoonoses, including reports of incidence and prevalence. We discuss those helminth diseases which are increasing in endemic areas and consider their geographical spread into new regions within the framework of globalization, urbanization and climate change to determine the effect these variables are having on disease incidence, transmission and the associated challenges presented for public health initiatives, including control and elimination.