Update on Baylisascariasis, a Highly Pathogenic Zoonotic Infection

Abstract

SUMMARYBaylisascaris 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. procyonisis 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.

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.…”

“…Despite expansion of the geographic distribution of Baylisascaris procyonis in the last 14 years (2) and probable increasing human exposure, baylisascariasis is likely an underreported disease: only 22 documented cases were reported in the United States during 1973-2010 (3,4). Laboratory and clinical diagnosis can be challenging: there is no commercially available serologic test in the United States, and although identification of larvae in tissue or specimens is confirmatory, this is not always possible or practical (3).…”

<i>Baylisascaris procyonis</i> un nemátodo del mapache urbano, agente zoonótico emergente por considerar como diagnóstico diferencial de larva migrans en Costa Rica. Revisión

“…Uno de las interacciones más notable es la que ocurre entre los mapaches, humanos y/o sus mascotas (perros y gatos). Estas interacciones pueden estar asociadas con la capacidad de transmisión de este nemátodo a animales domésticos y a seres humanos (Roscoe 1993;Bowman et al 2005;Graeff-Teixeira et al 2016). Bowman 2000, reportó el Baylisacaris procyonis en cachorros afectados con larva migrans, presentaron cuadros de tipo nervioso, observándose movimiento en círculo, parálisis del tren posterior, letargia, ceguera, ataxia y postración (Bowman 2000).…”

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

“…Larval stages of B. procyonis can cause clinical disease in a variety of paratenic vertebrate hosts, including humans, often resulting in fatal neurologic outcomes (Kazacos, 2001;Graeff-Teixeira et al, 2016). The diversity of wildlife that can become infected and the impact on some populations of hosts is increasingly recognized.…”