Baylisascariasis

Abstract

SUMMARY The raccoon roundworm, Baylisascaris procyonis, is the most common and widespread cause of clinical larva migrans in animals. In addition, it is increasingly recognized as a cause of devastating or fatal neural larva migrans in infants and young children and ocular larva migrans in adults. Humans become infected by accidentally ingesting infective B. procyonis eggs from raccoon latrines or articles contaminated with their feces. Two features distinguish B. procyonis from other helminthes that cause larva migrans: (i) its aggressive somatic migration and invasion of the central nervous system and (ii) the continued growth of larvae to a large size within the central nervous system. Typically, B. procyonis neural larva migrans presents as acute fulminant eosinophilic meningoencephalitis. Once invasion of the central nervous system has occurred, the prognosis is grave with or without treatment. To date, despite anthelmintic treatment of cases of B. procyonis neural larva migrans, there are no documented neurologically intact survivors. Epidemiologic study of human cases of neural larva migrans demonstrate that contact with raccoon feces or an environment contaminated by infective eggs and geophagia or pica are the most important risk factors for infection. In many regions of the United States, increasingly large populations of raccoons, with high rates of B. procyonis infection, live in close proximity to humans. Although documented cases of human baylisascariasis remain relatively uncommon, widespread contamination of the domestic environment by infected raccoons suggests that the risk of exposure and human infection is probably substantial. In the absence of early diagnosis or effective treatment, prevention of infection is the most important public health measure.

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

“…The geographic distribution, clinical presentations, exposure history, and sequelae reported in this case series are similar to those previously reported (3,8); however, unlike most case reports of Baylisascaris procyonis infection, there were no deaths in this series. The patients in this series all lived in areas where raccoons are common.…”

Parasites in stool samples in the environment of Ilha da Marambaia, Rio de Janeiro, Brazil: an approach in public health

“…Although eggs of Baylisascaris genus have been described in both canine and human infections and are indistinguishable from Ascaris sp., this parasite has never been reported in Brazil 6 . Insofar as the inhabitants of the Ilha da Marambaia have the habit to defecate on the soil, this study suggests that a possible source of environmental contamination for the said parasite was probably humans infected with A. lumbricoides.…”

Baylisascaris procyonis in Raccoons (Procyon lotor) in Eastern Tennessee

“…The prevalence of infection is reported to be highest in juvenile raccoons, and in the Midwest, Northeast, and West Coast of the United States, with frequencies ranging from 68% to 82% (Jacobson et al, 1982;Evans, 2002;Roussere et al, 2003;Moore et al, 2004;Gavin et al, 2005). Historically, prevalence estimates in the southeastern United States have been low (Harkema and Miller, 1964;Schaffer et al, 1981;Gavin et al, 2005;McCleery et al, 2005).…”

“…Raccoons are well adapted to living in close proximity to people, and their populations are often dense near suburban and urban parks and residences (Gavin et al, 2005). Raccoons use gardens, garbage, bird feeders, and pet food as food sources.…”

“…Increased interactions with raccoons are likely as human populations continue to expand into previously undisturbed natural habitats and naïve humans are unaware of the risks associated with interacting with wildlife. Additionally, with a general decrease in hunting, trapping, and preda-tion, it is estimated that the raccoon population of the United States will double over the next 10 yr (Gavin et al, 2005).…”