EID Journal Home > Volume 17, Number 7–July 2011
Volume 17, Number 7–July 2011
Neurognathostomiasis, a Neglected Parasitosis of the Central Nervous System
Juri Katchanov, Kittisak Sawanyawisuth, Verajit Chotmongkol, and Yukifumi Nawa Author affiliations: Mahidol University, Bangkok, Thailand (J. Katchanov, Y. Nawa); and Khon Kaen University, Khon Kaen, Thailand (K. Sawanyawisuth, V. Chotmongkol)
Suggested citation for this article
Gnathostomiasis is a foodborne zoonotic helminthic infection caused by the third-stage larvae of Gnathostoma spp. nematodes. The most severe manifestation involves infection of the central nervous system, neurognathostomiasis. Although gnathostomiasis is endemic to Asia and Latin America, almost all neurognathostomiasis cases are reported from Thailand. Despite high rates of illness and death, neurognathostomiasis has received less attention than the more common cutaneous form of gnathostomiasis, possibly because of the apparent geographic confinement of the neurologic infection to 1 country. Recently, however, the disease has been reported in returned travelers in Europe. We reviewed the English-language literature on neurognathostomiasis and analyzed epidemiology and geographic distribution, mode of central nervous system invasion, pathophysiology, clinical features, neuroimaging data, and treatment options. On the basis of epidemiologic data, clinical signs, neuroimaging, and laboratory findings, we propose diagnostic criteria for neurognathostomiasis.
Foodborne parasitic infections are common in the tropics, where many foodborne parasites are endemic and ingestion of raw shellfish and freshwater fish, as well as undercooked meat, is frequent among local populations (1). Increased international travel to areas endemic for these foodborne parasites and migration from tropical areas have led to the emergence of these diseases in temperate climates (2), where such infections are rarely seen by physicians and thus may not be considered in differential diagnoses.
Gnathostomiasis is a foodborne zoonotic helminthic infection caused by the third-stage larva of Gnathostoma spp. nematodes (Figure 1, panels A, B). At least 13 species have been identified (3), with 5 recorded in humans. G. spinigerum is the most common of these nematodes in Asia. Human infection with G. hispidum, G. doloresi, and G. nipponicum were found only in Japan (4). In the Americas, G. binucleatum is the only proven pathogenic Gnathostoma nematode in humans. Humans are infected primarily by eating raw or undercooked freshwater fish (Figure 1, panel C), frogs, and chicken. Humans are accidental unsuitable hosts; the parasite rarely develops to an adult worm, and the disease in humans is caused by the migrating larva.
Gnathostomiasis can be divided into cutaneous, visceral, and ocular forms, depending on the site of larval migration and subsequent signs and symptoms (2). The most common clinical presentation is the cutaneous one (Figure 1, panel D), which is characterized by localized, intermittent, migratory swellings of the skin and is often associated with localized pain, pruritus, and erythema (5,6). Visceral involvement can manifest in virtually any organ and any part of the body (3). The most severe manifestation of the visceral disease is involvement of the central nervous system (CNS), i.e., neurognathostomiasis.
Neurognathostomiasis has been reported only in G. spinigerum infections (3).
We found 24 reports describing a total of 248 patients with neurognathostomiasis published in English-language literature. In this article, we review epidemiology, mode of CNS invasion, pathophysiology, clinical features, neuroimaging data, and treatment options, and we propose diagnostic criteria for this emerging disease.
Neurognathostomiasis CDC EID
Suggested Citation for this Article
Katchanov J, Sawanyawisuth K, Chotmongkol V, Nawa Y. Neurognathostomiasis, a neglected parasitosis of the central nervous system. Emerg Infect Dis [serial on the Internet]. 2011 Jul [date cited]. http://www.cdc.gov/EID/content/17/7/1174.htm
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Yukifumi Nawa, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajavithi Rd, Bangkok 10400, Thailand; email: firstname.lastname@example.org