너구리 회충. EndoTODAY 이준행

[너구리 회충, Raccoon roundworm, Baylisascaris procyonis]

우리나라는 과거 회충 Ascaris lumbricoides이 많았지만 지금은 아주 드물게 진단됩니다. 요즘은 오히려 개회충 Toxocara canis 유충 감염이나 고래회충의 유충인 아니사키스 감염이 더 흔한 편입니다.

최근 미국 드라마 Doctor House를 보면서 미국에서는 너구리 회충(raccoon roundworm)이 문제라는 것을 알게 되었습니다. 자폐증을 앓고 있는 아이가 마당의 잔디와 모래에서 노는 것을 좋아했는데 어느 날 seizure와 blurred vision으로 입원하였는데, 감별진단이 잘 되지 않아 고생하다가 결국 名醫 House 박사가 너구리 회충을 진단하여 albendazole 먹고 쉽게 치료되었다는 이야기였습니다.

2016년 미국 MMWR에서 옮깁니다 (MMWR 2016 Sep 9).

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.

증례 보고 하나를 소개합니다.

Raccoon Roundworm (Baylisascaris procyonis) Encephalitis: Case Report and Field Investigation
Baylisascaris procyonis is a common and widespread parasite of raccoons in the United States and Canada. With large raccoon populations occurring in many areas, the potential risk of human infection with B procyonis is high. We report a case of severe raccoon roundworm (B procyonis) encephalitis in a young child to illustrate the unique clinical, diagnostic, and treatment aspects, as well as public health concerns ofB procyonis infection. Acute and convalescent serum and cerebrospinal fluid samples from the patient were tested for antibodies against B procyonis to assist in documenting infection. An extensive field survey of the patient's residence and the surrounding community was performed to investigate raccoon abundance and to determine the extent of raccoon fecal contamination and B procyonis eggs in the environment. The patient evidenced serologic conversion, and the field investigation demonstrated a raccoon population far in excess of anything previously reported. There was abundant evidence of B procyonis eggs associated with numerous sites of raccoon defecation around the patient's residence and elsewhere in the community. Because B procyonis can produce such severe central nervous system disease in young children, it is important that pediatricians are familiar with this infection. The public should be made aware of the hazards associated with raccoons and B procyonis to hopefully prevent future cases of B procyonisinfection.
Fundus photograph of the macula of the right eye, showing discrete punctate chorioretinal scars in linear track-like configuration.
Axial T2-weighted MRIs (TR: 2500 msec; TE: 80 msec) showing patchy T2 hyperintensity in the central white matter, particularly in the corona radiata. This abnormality progresses dramatically between the initial scan (top row: 8/31) and the follow-up 10 days later (bottom row: 9/10). TE indicates echo time; TR, repetition time.

이와 비슷한 종류도 많다고 합니다. 참고 문헌 하나를 소개합니다. Beyond the raccoon roundworm: The natural history of non-raccoon Baylisascaris species in the New World (Int J Parasitol Parasites Wildl 2017).

우리나라에서는 기생충 박사인 저도 모를 정도로 잘 알려져있지 않지만, 미국에서는 한인 교포 신문에 나올 정도로 제법 유명한 모양입니다.

[References]

1) EndoTODAY 기생충