Gnathostomiasis acquired after consumption of raw freshwater fish in the Amazon region: a report of two cases in Brazil

Abstract Gnathostomiasis is a parasitic zoonosis caused by the helminth Gnathostoma spp., acquired through the consumption of raw or undercooked contaminated aquatic animals.The disease is endemic in Southeast Asia and Central America. Two male patients, both middle-aged, presented with single itchy erythemato-edematous plaques on the anterior thorax and left flank. Both had consumed raw fish in the Amazon region. The clinical and epidemiological examinations suggested gnathostomiasis, and treatment with albendazole caused total regression of the lesions. Health teams should be familiar with the disease to provide correct diagnosis. The control strategy should be based on health education for the population.

Vulvitis migratoria causada por gnatostomiasis importada / Migratory vulvitis caused by imported gnathostomiasis

Resumen La gnatostomiasis es una parasitosis emergente en países no endémicos. Este nematodo zoonótico requiere de agua dulce para su ciclo de vida, donde sus larvas se enquistan principalmente en peces. La migración subcutánea de las larvas produce habitualmente una paniculitis eosinofílica de rápido avance. Se describe un caso clínico de un paciente con una lesión migratoria, sin mejoría clínica con terapia antibacteriana. La búsqueda de factores de riesgo, sumado a la evolución y a los hallazgos de laboratorio hizo sospechar el diagnóstico. La gnatostomiasis debe ser sospechado en pacientes con lesiones de piel migratorias, que han consumido pescado crudo durante viajes a países endémicos en Sudamérica o Asia.

Gnathostomiasis is an emerging disease in non-endemic countries. This zoonotic nematode requires aquatic freshwater environments to complete its life cycle where larvae get encrusted in fishes. Typically, the infection manifests as migratory subcutaneous lesion caused by the larvae trak, which produces an eosinophilic panniculitis. Here we describe a patient who presented a migratory lesion with no response to antimicrobial therapy, a careful travel and food history together with specific laboratory tests led to the correct diagnosis. Gnathostomiasis should be suspected in patients with migratory skin lesions who have consumed raw freshwater fish during travel to endemic countries in South America or Asia.

Gnathostomiasis: an emerging infectious disease relevant to all dermatologists

Abstract: Gnathostomiasis is a parasitic infection caused by the third larval stage of nematodes of the genus Gnathostoma. The disease is endemic in some countries around the world. In the American continent, the majority of cases is concentrated in Mexico, Ecuador, and Peru. However, due to increasing traveling either at the intercontinental or intracontinental level, the disease is seen each time more frequently in tourists. Furthermore, countries, such as Brazil, that have never been considered endemic are reporting autochthonous cases. The disease usually presents as a deep-seated or slightly superficial migratory nodule in patients with history of eating raw fish, in the form of ceviche, sushi, or sashimi. Along with the clinical presentation, diagnostic criteria include either blood or tissue eosinophilia. In most instances, these criteria are enough for the attending physician to institute therapy. Chances of finding the parasite are low, unless the biopsy is taken from a very specific area that develops after antiparasitic treatment is started. The potential of other organ involvement with more serious consequences should always be kept in mind.

An Overview of Fish-borne Nematodiases among Returned Travelers for Recent 25 Years– Unexpected Diseases Sometimes Far Away from the Origin

Along with globalization of traveling and trading, fish-borne nematodiases seems to be increasing in number. However, apart from occasional and sporadic case reports or mini-reviews of particular diseases in particular countries, an overview of fish-borne nematodiasis among travelers have never been performed. In this review, we gathered fish-borne nematodiasis among travelers for recent 25 years by an extensive global literature survey using appropriate keywords, e.g. travelers diseases, human infection, anisakiasis, gnathostomiasis, capillariasis, sushi, sashimi, ceviche, Gnathostoma, Pseudoterranova, Anisakis, Capillaria, etc., as well as various combinations of these key words. The Internet search engines PubMed, Medline, Google and Googler Scholar were used as much as possible, and the references of every paper were checked in order to identify useful and reliable publications. The results showed unexpectedly high incidence of gnathostomiasis and low incidence of anisakidosis. The different incidence values of the infection with several fish-borne zoonotic nematode species are discussed, as well as some epidemiological aspects of the infections. The difficulties of differential diagnosis in non-endemic countries are emphasized. It is concluded that travelers must avoid risky behaviors which can lead to infection and that physicians and health authorities must advice travelers on the risks of eating behaviors during travel.

Gnatostomiasis cutánea, primer caso confirmado en Colombia / Cutaneous gnathostomiasis, first confirmed case in Colombia

La gnatostomiasis es una zoonosis parasitaria causada por algunas especies del género de helmintos Gnathostoma . La presentación clínica es muy variada y su diagnóstico constituye un desafío; es endémica en países tropicales y subtropicales, y la transmisión se asocia con el consumo de carne de animales acuáticos, cruda o mal cocida. En las últimas décadas, el creciente turismo internacional y el consumo de alimentos exóticos, han provocado un notable aumento de casos de la enfermedad. En nuestro país no se ha reportado ningún caso confirmado de gnatostomiasis. Se presenta el caso de un hombre colombiano de 63 años de edad, viajero frecuente al exterior, que consultó por presentar síntomas gastrointestinales. Durante la hospitalización desarrolló una lesión cutánea en el flanco abdominal derecho, de la cual se extrajo una larva cuya descripción morfológica permitió clasificarla como Gnathostoma spinigerum . Se trata de la primera confirmación de un caso importado de gnatostomiasis en Colombia. En este artículo se discuten las generalidades, la etiología, la patogenia y el tratamiento de la enfermedad, con especial énfasis en las características particulares de este paciente.

Gnathostomiasis is a parasitic zoonosis caused by some species of helminthes belonging to the genus Gnathostoma . It has a wide clinical presentation and its diagnosis is a challenge. Tropical and subtropical countries are endemic, and its transmission is associated with eating raw or undercooked meat from fresh water animals. Increasing global tourism and consuming exotic foods have produced a noticeable rise in cases of the disease in the last decades. However, in our country, there has not been any confirmed case of gnathostomiasis previously reported. We present the case of a 63-year-old Colombian man with an international travel history, who presented with gastrointestinal symptoms. During the hospital stay, he developed a cutaneous lesion on the upper right abdominal quadrant, where later, a larva was found. A morphological study allowed us to identify it as Gnathostoma spinigerum . As such, this is the first report of an imported case of gnathostomiasis confirmed in Colombia. This article describes the principles, etiology, pathogenic cycle and treatment of this disease with special considerations to our patient´s particular features.

Larval Gnathostoma spinigerum Detected in Asian Swamp Eels, Monopterus albus, Purchased from a Local Market in Yangon, Myanmar

The present study was performed to determine the infection status of swamp eels with Gnathostoma sp. larvae in Myanmar. We purchased total 37 Asian swamp eels, Monopterus albus, from a local market in Yangon in June and December 2013 and 2014. All collected eels were transferred with ice to our laboratory and each of them was examined by the artificial digestion technique. A total of 401 larval gnathostomes (1-96 larvae/eel) were detected in 33 (89.2%) swamp eels. Most of the larvae (n=383; 95.5%) were found in the muscle. The remaining 18 larvae were detected in the viscera. The advanced third-stage larvae (AdL3) were 2.3-4.4 mm long and 0.25-0.425 mm wide. The characteristic head bulb (0.093 x 0.221 mm in average size) with 4 rows of hooklets, muscular long esophagus (1.025 mm), and 2 pairs of cervical sacs (0.574 mm) were observed by light microscopy. The average number of hooklets in the 1st, 2nd, 3rd, and 4th rows was 41, 45, 48, and 51, respectively. As scanning electron microscopic findings, the characteristic 4-5 rows of hooklets on the head bulb, a cervical papilla, tegumental spines regularly arranged in the transverse striations, and an anus were well observed. Based on these morphological characters, they were identified as the AdL3 of Gnathostoma spinigerum. By the present study, it has been confirmed for the first time that Asian swamp eels, M. albus, from Yangon, Myanmar are heavily infected with G. spinigerum larvae.

Dermatosis de origen alimentario al regreso de un viaje: gnathostomiasis / Foodborne dermatosis after traveling: gnathostomiasis

Se describe el caso de un paciente de 32 años de edad, residente en Buenos Aires, con manifestaciones dermatológicas compatibles con gnathostomiasis. Había realizado un viaje a Colombia en el mes previo a la aparición de la sintomatología. Allí consumió cebiche (pescado crudo marinado en jugo de limón) en reiteradas oportunidades. El cuadro clínico se presentó como paniculitis eritematosa y migratoria acompañada de eosinofilia sanguínea. Se le realizó biopsia cutánea de una lesión y el diagnóstico anatomopatológico fue "paniculitis eosinofílica". La tríada de paniculitis migratoria, eosinofilia sanguínea y el consumo de pescado crudo durante el viaje a Colombia fue sugestiva de gnathostomiasis por lo que se indicó tratamiento con ivermectina con buena evolución inicial y recaída posterior. Se realizó un nuevo tratamiento con la misma droga con buena evolución y sin recaídas durante tres años de seguimiento. La afección dermatológica es un motivo frecuente de consulta al regreso de un viaje, y representa la tercera causa de morbilidad en viajeros. Es muy importante el reconocimiento de las enfermedades que pueden tener manifestación cutánea, ya que muchas de ellas son potencialmente graves y pueden poner en riesgo la vida del paciente si no son oportunamente diagnosticadas y tratadas.

We describe a case of a 32-year-old man, resident in Buenos Aires, with dermatologic manifestations compatible with gnathostomiasis. The patient had traveled to Colombia in the month prior to the onset of symptoms. There, he repeatedly ate ceviche (raw fish marinated in lemon juice). He presented with an erythematous migratory panniculitis accompanied by eosinophilia. He underwent skin biopsy of a lesion and pathological diagnosis was "eosinophilic panniculitis". The triad of migratory panniculitis, eosinophilia and consume of raw fish during the trip to Colombia was suggestive of gnathostomiasis. Ivermectin treatment started out with good initial response but subsequent relapse. We performed a new treatment with the same drug with good results and no relapses during three years of follow up. The dermatological disease is common upon return from a trip, and is the third leading cause of morbidity in travelers. It is very important to recognize cutaneous manifestations of disease as many of them are potentially serious and may compromise the patient's life if not promptly diagnosed and treated.

A Recombinant Matrix Metalloproteinase Protein from Gnathostoma spinigerum for Serodiagnosis of Neurognathostomiasis

Neurognathostomiasis is a severe form of human gnathostomiasis which can lead to disease and death. Diagnosis of neurognathostomiasis is made presumptively by using clinical manifestations. Immunoblotting, which recognizes antigenic components of molecular mass 21 kDa and 24 kDa in larval extracts of Gnathostoma spinigerum (Gs 21/24), has high sensitivity and specificity for diagnosis of neurognathostomiasis. However, only very small amounts of the Gs 21/24 antigens can be prepared from parasites harvested from natural or experimental animals. To overcome this problem, we recently produced a recombinant matrix metalloproteinase (rMMP) protein from G. spinigerum. In this study, we evaluated this rMMP alongside the Gs 21/24 antigens for serodiagnosis of human neurognathostomiasis. We studied sera from 40 patients from Srinagarind Hospital, Khon Kaen University, Thailand, with clinical criteria consistent with those of neurognathostomiasis, and sera from 30 healthy control adults from Thailand. All sera were tested for specific IgG antibodies against both G. spinigerum crude larval extract and rMMP protein using immunoblot analysis. The sensitivity and specificity for both antigenic preparations were all 100%. These results show that G. spinigerum rMMP protein can be used as an alternative diagnostic antigen, in place of larval extract, for serodiagnosis of neurognathostomiasis.

Detection of Gnathostoma spinigerum Antibodies in Sera of Non-Traumatic Subarachnoid Hemorrhage Patients in Thailand

Gnathostoma spinigerum can cause subarachnoid hemorrhage (SAH). The detection of specific antibodies in serum against G. spinigerum antigen is helpful for diagnosis of neurognathostomiasis. There is limited data on the frequency of G. spinigerum infection in non-traumatic SAH. A series of patients diagnosed as non-traumatic SAH at the Srinagarind Hospital, Khon Kaen University, Thailand between January 2011 and January 2013 were studied. CT or MR imaging of the brain was used for diagnosis of SAH. Patients were categorized as aneurysmal subarachnoid hemorrhage (A-SAH) or non-aneurysmal subarachnoid hemorrhage (NA-SAH) according to the results of cerebral angiograms. The presence of specific antibodies in serum against 21- or 24-kDa G. spinigerum antigen was determined using the immunoblot technique. The detection rate of antibodies was compared between the 2 groups. Of the 118 non-traumatic SAH patients for whom cerebral angiogram and immunoblot data were available, 80 (67.8%) patients had A-SAH, whereas 38 (32.2%) had NA-SAH. Overall, 23.7% were positive for specific antibodies against 21- and/or 24-kDa G. spinigerum antigen. No significant differences were found in the positive rate of specific antibodies against G. spinigerum in both groups (P-value=0.350).

Cutaneous Gnathostomiasis with Recurrent Migratory Nodule and Persistent Eosinophilia: a Case Report from China

The present study reports a human case of cutaneous gnathostomiasis with recurrent migratory nodule and persistent eosinophilia in China. A 52-year-old woman from Henan Province, central China, presented with recurrent migratory reddish swelling and subcutaneous nodule in the left upper arm and on the back for 3 months. Blood examination showed eosinophila (21.2%), and anti-sparganum antibodies were positive. Skin biopsy of the lesion and histopathological examinations revealed dermal infiltrates of eosinophils but did not show any parasites. Thus, the patient was first diagnosed as sparganosis; however, new migratory swellings occurred after treatment with praziquantel for 3 days. On further inquiring, she recalled having eaten undercooked eels and specific antibodies to the larvae of Gnathostoma spinigerum were detected. The patient was definitely diagnosed as cutaneous gnathostomiasis caused by Gnathostoma sp. and treated with albendazole (1,000 mg/day) for 15 days, and the subsequent papule and blister developed after the treatment. After 1 month, laboratory findings indicated a reduced eosinophil count (3.3%). At her final follow-up 18 months later, the patient had no further symptoms and anti-Gnathostoma antibodies became negative. Conclusively, the present study is the first report on a human case of cutaneous gnathostomiasis in Henan Province, China, based on the past history (eating undercooked eels), clinical manifestations (migratory subcutaneous nodule and persistent eosinophilia), and a serological finding (positive for specific anti-Gnathostoma antibodies).

Gnathostoma spinigerum Infection in the Upper Lip of a Korean Woman: An Autochthonous Case in Korea

Autochthonous human gnathostomiasis had never been reported in the Republic of Korea. We report here a case of Gnathostoma spinigerum infection in a 32-year-old Korean woman, presumed to have been infected via an indigenous route. The patient had experienced a painful migratory swelling near the left nasolabial fold area of the face for a year, with movement of the swelling to the mucosal area of the upper lip 2 weeks before surgical removal of the lesion. Histopathological examinations of the extracted tissue revealed inflammation with heavy eosinophilic infiltrations and sections of a nematode suggestive of a Gnathostoma sp. larva. The larva characteristically revealed about 25 intestinal cells with multiple (3-6) nuclei in each intestinal cell consistent with the 3rd-stage larva of G. spinigerum. The patient did not have any special history of travel abroad except a recent trip, 4 months before surgery, to China where she ate only cooked food. The patient is the first recorded autochthonous case of G. spinigerum infection in Korea.

Imported Intraocular Gnathostomiasis with Subretinal Tracks Confirmed by Western Blot Assay

We report a case of intraocular gnathostomiasis diagnosed by western blot assay in a patient with subretinal tracks. A 15-year-old male patient complained of blurred vision in the right eye, lasting for 2 weeks. Eight months earlier, he had traveled to Vietnam for 1 week and ate raw wild boar meat and lobster. His best-corrected visual acuity was 20/20 in both eyes and anterior chamber examination revealed no abnormalities. Fundus examination showed subretinal tracks in the right eye. Fluorescein angiography and indocyanine green angiography showed linear hyperfluorescence of the subretinal lesion observed on fundus in the right eye. Ultrasound examination revealed no abnormalities. Blood tests indicated mild eosinophilia (7.5%), and there was no abnormality found by systemic examinations. Two years later, the patient visited our department again for ophthalmologic evaluation. Visual acuity remained 20/20 in both eyes and the subretinal tracks in the right eye had not changed since the previous examination. Serologic examination was performed to provide a more accurate diagnosis, and the patient's serum reacted strongly to the Gnathostoma nipponicum antigen by western blot assay, which led to a diagnosis of intraocular gnathostomiasis. This is the first reported case of intraocular gnathostomiasis with subretinal tracks confirmed serologically using western blot in Korea.

Positivity and Intensity of Gnathostoma spinigerum Infective Larvae in Farmed and Wild-Caught Swamp Eels in Thailand

From July 2008 to June 2009, livers of the swamp eels (Monopterus alba) were investigated for advanced third-stage larvae (AL3) of Gnathostoma spinigerum. Results revealed that 10.2% (106/1,037) and 20.4% (78/383) of farmed eels from Aranyaprathet District, Sa Kaeo Province and those of wild-caught eels obtained from a market in Min Buri District of Bangkok, Thailand were infected, respectively. The prevalence was high during the rainy and winter seasons. The infection rate abruptly decreased in the beginning of summer. The highest infection rate (13.7%) was observed in September and absence of infection (0%) in March-April in the farmed eels. Whereas, in the wild-caught eels, the highest rate (30.7%) was observed in November, and the rate decreased to the lowest at 6.3% in March. The average no. (mean+/-SE) of AL3 per investigated liver in farmed eels (1.1+/-0.2) was significantly lower (P=0.040) than those in the caught eels (0.2+/-0.03). In addition, the intensity of AL3 recovered from each infected liver varied from 1 to 18 (2.3+/-0.3) in the farmed eels and from 1 to 47 (6.3+/-1.2) in the caught eels, respectively. The AL3 intensity showed significant difference (P=0.011) between these 2 different sources of eels. This is the first observation that farmed eels showed positive findings of G. spinigerum infective larvae. This may affect the standard farming of the culture farm and also present a risk of consuming undercooked eels from the wild-caught and farmed eels.

Gnatostomiasis, experiencia en una práctica privada en Lima-Perú / Gnathostomiasis, experience in private practice in Lima, Peru

Objetivo: determinar las características epidemiológicas y clínicas de la gnatostomiasis en un consultorio de práctica privada de Lima. Material y métodos: estudio descriptivo de una serie de pacientes con diagnóstico de gnatostomiasis en un consultorio privado de dermatología en Lima. Se revisaron las historias de los pacientes diagnosticados de gnatostomiasis según criterio clínico e histopatológico entre enero del 2010 y setiembre del 2011; además se realizó una encuesta telefónica para obtener los antecedentes epidemiológicos. Resultados: se identificaron 20 pacientes de los cuales 18 tuvieron los datos clínicos completos. La población en estudio estuvo conformada por 18 pacientes con diagnóstico de gnatostomiasis. Todos residían en distritos de estrato social alto. La edad promedio fue de 47.5 años. La forma de presentación clínica más frecuente fue la infamatoria o paniculítica y la localización topográfica más frecuente fue en tórax. Se evidenció eosinofilia en trece pacientes. Cinco pacientes recibieron albendazol 400mg/d por 21 días y trece pacientes recibieron tratamiento combinado de albendazol 400-800mg/d por 21 días con ivermectina 200ug/kg/dosis en una o dos oportunidades. La mayor frecuencia de consumo de pescado crudo fue de una a dos veces por semana. El tipo de comida más consumida fue el cebiche. El tipo de pescado más frecuente de consumo fue la corvina en restaurantes exclusivos de precios altos. Conclusión: el número de casos de gnatostomiasis vistos en el presente reporte fue mayor en el periodo del 2011 comparado con el 2010. La forma de presentación clínica más frecuente fue la infamatoria o profunda. El pescado crudo más frecuente consumido por estos pacientes fue el de corvina en forma de cebiche en restaurantes en el rango de alto precio. Todos los pacientes tuvieron buena respuesta terapéutica con los antiparasitarios, siendo la combinación de albendazol e ivermectina la más utilizada.

Aim: to determine the epidemiological and clinical characteristics of gnathostomiasis in a private practice setting in Lima, Peru. Methods: descriptive study of a group of patients with gnathostomiasis attended at a dermatology private clinic at Lima. We reviewed the records of all patients with diagnosis of gnathostomiasis, based on clinical and histopathological findings, from January 2010 to September 2011; we also conducted a telephone interview to obtain additional epidemiological data. Results: we identified 20 cases of which 18 had a complete clinical history. All subjects reported residing in a higher social strata neighborhood. The average age was 47.2 years. The most common clinical presentation was the deep paniculitic form and chest was the most common topographic location. Eosinophilia was present in 13 patients. Five patients received albendazole 400 mg / d for 21 days and thirteen patients were treated with combination of albendazole 400-800mg/d for 21 days and ivermectin 200ug/kg/dosis in one or two occasions. The highest frequency of raw fish consumption before the disease was once to twice a week. Regarding the type of food, most patients consumed cebiche. The most common type of consumed fish was seabass in exclusive restaurants of high prices. Conclusion: the number of gnathostomiasis cases seen in this report was higher in the period of 2011 compared with 2010. The most common clinical presentation was the inflamatory or paniculitic form. Seabass cebiche was the most common type of raw fish consumed by patients, always in expensive restaurants. All patients had good therapeutic response to antiparasitics, with the combination of albendazole and ivermectin as the most used therapeutic regimen.