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Biological Health Hazard – Raccoon roundworm (Baylisascaris procyonis), Human exposure: U.S.A.


Published Date: 2017-01-03 16:46:47
Subject: PRO/AH/EDR> Baylisascaris procyonis, humans – USA: exposure
Archive Number: 20170103.4739629

Date: Sun 1 Jan 2017
Source: Outbreak News Today [edited]
(Raccoon roundworm: Study suggests subclinical infections in wildlife rehabilitators)

_Baylisascaris procyonis_, also known as the raccoon roundworm, is the most common and widespread cause of clinical larva migrans in animals. It is a ubiquitous roundworm infection of raccoons (_Procyon lotor_) and is emerging as an important helminthic zoonosis, primarily in young children.

_B. procyonis_ roundworms can cause potentially fatal neural larva migrans in many species, including humans. However, the clinical spectrum of _B. procyonis_ is not completely understood, according to researchers in a new study published in the CDC journal, Emerging Infectious Diseases.

Wildlife rehabilitators may represent a population at risk for subclinical _B. procyonis_ due to frequent contact with raccoons and their feces, which may contain infectious larvated _B. procyonis_ eggs.

During 2012-2015, serum samples were collected and analyzed for _B. procyonis_ IgG using a recombinant _B. procyonis_ repeat antigen 1 protein Western blot. A questionnaire was also administered to determine current involvement in rehabilitation activities.

Nine out of 10 of the 347 participants reported current involvement in rehabilitation activities. 24 (7 percent) of participants tested positive for _B. procyonis_ antibodies.

Based on their findings, researchers suggest that exposure to _B. procyonis_ may occur without clinical disease. See study for details to include complete data and limitations.

[Byline: Robert Herriman]

Communicated by:
ProMED-mail from HealthMap Alerts

[The study referred to is: “Sapp SG et al. _Baylisascaris procyonis_ Roundworm Seroprevalence among Wildlife Rehabilitators, United States and Canada, 2012-2015. Emerg Infect Dis. 2016 Dec;22(12):2128-2131. doi: 10.3201/eid2212.160467;” (

The assay used was an immunoblot using a recombinant _B. procyonis_ antigen with an estimated sensitivity of 88% and a specificity of 98% (Rascoe LN et al. Interlaboratory optimization and evaluation of a serological assay for diagnosis of human baylisascariasis. Clin Vaccine Immunol. 2013;20:1758-63).

_B. procyonis_ infections in humans, especially meningitis, are almost always fatal and difficult to treat (Langelier C et al. _Baylisascaris procyonis_-Associated Meningoencephalitis in a Previously Healthy Adult, California, USA. Emerg Infect Dis. 2016 Aug;22(8):1480-4. doi: 10.3201/eid2208.151939 (

Exposure to _B. procyonis_ eggs in the gut may elicit an antibody response even without invasive infection. – Mod.EP

A HealthMap/ProMED-mail map can be accessed at:]

See Also

Baylisascaris – Canada: (BC) raccoon: 20140204.2254368

Baylisascaris – Canada (ON) 20050907.2660

Baylisascaris – USA (California) 20020520.4282
Baylisascaris procyonis, decontamination 20020112.3238
Baylisascaris procyonis, humans – USA (02) 20020109.3214
Baylisascaris procyonis, humans – USA 20020108.3197

A ProMED-mail post
ProMED-mail is a program of the International Society for Infectious Diseases

Related:  Parasites and Pestilence. It has interactive maps you can click to see which parasites are found where.

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