Human gnathostomiasis in Sri Lanka: an underreported disease?

A healthy young man from Sri Lanka, currently living in Switzerland, consulted at the University Hospital of Geneva with a history of painful erythema and swelling of the left forearm. Laboratory tests showed a slight eosinophilia. Western blot serology for Gnathostoma spp, inconclusive at presentation, became positive 2 weeks later.

Human gnathostomiasis: a neglected food-borne zoonosis.

BACKGROUND: Human gnathostomiasis is a food-borne zoonosis. Its etiological agents are the third-stage larvae of Gnathostoma spp. Human gnathostomiasis is often reported in developing countries, but it is also an emerging disease in developed countries in non-endemic areas. The recent surge in cases of human gnathostomiasis is mainly due to the increasing consumption of raw freshwater fish, amphibians, and reptiles. METHODS: This article reviews the literature on Gnathostoma spp. and the disease that these parasites cause in humans. We review the literature on the life cycle and pathogenesis of these parasites, the clinical features, epidemiology, diagnosis, treatment, control, and new molecular findings on human gnathostomiasis, and social-ecological factors related to the transmission of this disease. CONCLUSIONS: The information presented provides an impetus for studying the parasite biology and host immunity. It is urgently needed to develop a quick and sensitive diagnosis and to develop an effective regimen for the management and control of human gnathostomiasis.

Autochthonous Gnathostomiasis in Madagascar.

We used molecular tools to identify an autochthonous case of gnathostomiasis in Madagascar. This severe ocular infection, caused by Gnathostoma spinigerum nematodes, led to vision loss in the patient's left eye. Clinicians should be aware of this parasitosis in Madagascar and other countries in Africa.

Emerging infections: mimickers of common patterns seen in dermatopathology.

The following discussion deals with three emerging infection diseases that any dermatopathologist working in the northern hemisphere can come across. The first subject to be dealt with is gnathostomiasis. This parasitic disease is produced by the third larvarial stage of the parasite that in most patients is associated with the ingestion of raw fish. Epidemiologically, it is most commonly seen in South East Asia, Japan, China, and the American continent, mainly in Mexico, Ecuador, and Peru. Nowadays, the disease is also seen in travelers living in the developed countries who recently came back from visiting endemic countries. The disease produces a pattern of migratory panniculitis or dermatitis with infiltration of eosinophils in tissue. The requirements for making the diagnosis are provided, including clinical forms, common histological findings on skin biopsy as well as the use of ancillary testing. Buruli ulcer, a prevalent mycobacterial infection in Africa, is described from the clinical and histopathological point of view. The disease has been described occasionally in Central and South America as well as in developed countries such as Australia and Japan; Buruli ulcer has also been described in travelers returning from endemic areas. Clinically, the disease is characterized by large, painless ulcerations with undermined borders. Systemic symptoms are usually absent. Classical histological findings include a particular type of fat necrosis and the presence of abundant acid fast bacilli in tissue. Such findings should raise the possibility of this disease, with the purpose of early therapeutically intervention. Lastly, the infection by free living ameba Balamuthia mandrillaris, an emerging condition seen in the US and Peru, is extensively discussed. Special attention is given to clinical and histological characteristics, as well as to the clues for early diagnosis and the tools available for confirmation.

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 fishborne 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.

Seafood-borne parasitic diseases in Australia: are they rare or underdiagnosed?

Australia is a multicultural country surrounded by water where seafood is regularly consumed. Literature suggests that some popular edible fish sold in fish markets may be infected with parasites transmissible to humans (notably, anisakids and other helminths); however the number of reported human cases due to these parasites is low. In this article we critically review topical publications to understand whether the low number of human infection is due to lack of expertise in Australia to identify and diagnose accurately seafood-borne parasitic infections. The risk these parasites pose to humans may be underestimated due to: (i) errors or inability of diagnosing these infections, primarily due to less sensitive and specific serological tests and misidentifying parasites without a taxonomist in the diagnostic team; and (ii) medical practitioners not being aware of these parasites or not considering them in the differential diagnosis even in patients with history of regular raw or undercooked seafood consumption.

Sushi, ceviche and gnathostomiasis - A case report and review of imported infections.

We describe a case of imported cutaneous gnathostomiasis in a Thai patient living in France. Gnathostomiasis is a zoonosis of food origin. The disease is endemic in Southeast Asia and Latin America. However, over the past 30 years, an increasing number of imported cases has been described in Europe and America. The disease is rare in Western Europe and the majority of cases described had a cutaneous clinical presentation. The disease may sometimes be confused with allergy, leading to a delay in diagnosis. Visceral symptoms are rare but may follow severe attacks. A definitive diagnosis can be obtained by the isolation of larvae from skin biopsies, but these are rarely performed. The diagnosis is usually presumptive, based on a combination of anamnestic, clinical, and biological factors. Several courses of the anti-helminths, albendazole or ivermectin, are often necessary. Although rare, the diagnosis should be evoked systematically in a migrant or traveller returning from an endemic area with cutaneous lesions.

Ocular Gnathostomiasis-Update of Earlier Survey.

Ocular gnathostomiasis is rather a rare food-borne zoonosis caused by infection with the larvae of several species of genus Gnathostoma and is a representative ocular larva migrans syndrome. In our previous literature survey, we found 73 cases of ocular gnathostomiasis reported up to and including 2009, though additional sporadic cases have been reported in Asia and the Americas since that report. Here, we review 10 additional cases reported since 2010, and also update current findings regarding epidemiological and clinical features in affected patients.

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.

First reported case of intraocular Gnathostoma spinigerum in Cambodia.

A live intraocular nematode was identified from a 37 year-old man presented with iritis, pain, redness, lacrimation, swelling, vision loss and intermittent blindness during many hours per day of the left eye. By using slit lamp examination, a worm was removed from iris in an ophthalmology outpatient department setting and sent to the Medical Microbiology Laboratory, Institut Pasteur du Cambodge. Gnathostoma spinigerum was identified, based on its typical morphology via microscopic examination. Based on our diagnosis, the patient was treated by oral albendazole and responded well to this therapy.

Three Human Gnathostomiasis Cases in Thailand with Molecular Identification of Causative Parasite Species.

Human gnathostomiasis is one of the important food-borne parasitic zoonoses. The disease is caused by a spirurid roundworm of the genus Gnathostoma. Here, we describe three parasitological confirmed cases of human gnathostomiasis, caused by Gnathostoma spinigerum, in a hospital in Thailand during 2004-2012. Clinical characteristics, treatment, and outcome of cases were revealed. Parasites were accidentally recovered from patients and morphologically identified as Gnathostoma species. Confirmed diagnosis and identification of causative parasite species was made by DNA extraction of the recovered worms, followed by a polymerase chain reaction (PCR) of the second internal transcribed spacer region (ITS2) of DNA and the partial cytochrome c oxidase subunit 1 (cox-1) gene. Sequences corresponding to ITS2 and cox-1 were similar to G. spinigerum. To our knowledge, this study represents the first molecular confirmation that recovered G. spinigerum is a causative agent of human infection in Thailand.

Gnathostomiasis: An Emerging Infection of Raw Fish Consumers in Gnathostoma Nematode-Endemic and Nonendemic Countries.

BACKGROUND: Gnathostomiasis, a helminthic infection commonly reported in Southeast Asia and Latin America, may follow consumption of raw seafood infected with muscle-encysted larvae of Gnathostoma species nematodes. As a result of increasingly exotic tastes for local ethnic dishes, including raw seafood, some regions outside of gnathostome-endemic areas import live species for raw consumption. This may facilitate imported human gnathostomiasis or potentially the establishment of this zoonosis in formerly nonendemic regions. Traveling to a gnathostome-endemic area is no longer a criterion for diagnosis. The objectives of this review are to enhance clinician awareness of this infection by describing the behavioral risk factors for its acquisition, life-cycle, clinical manifestations, diagnosis, management, and prevention. METHODS: Internet search engines were queried with the key medical subject heading words. Case reports, case series, epidemiological investigations, and laboratory studies were reviewed; high risk behaviors for gnathostomiasis were identified; and human cases were stratified as cutaneous gnathostomiasis, visceral gnathostomiasis, neurognathostomiasis, and ocular gnathostomiasis. RESULTS: The greatest risk factors for gnathostomiasis included the consumption of raw freshwater seafood dishes in endemic regions and the consumption of raw imported or domestic seafood dishes in households and ethnic restaurants in many nonendemic regions. CONCLUSIONS: Gnathostomiasis is no longer a disease of returning travelers, and autochthonous cases may be anticipated to increase as a result of the importation of live Gnathostoma-infected species and the potential establishment of regional zoonoses of Gnathostoma-infected wild species. Since the eradication of gnathostomiasis is unlikely given the global distribution of Gnathostoma nematodes, the only effective preventive strategy is to educate persons in endemic and nonendemic areas that fish, eels, frogs, snakes, and birds must be cooked thoroughly first before eating and not eaten raw or marinated. The onset of migratory subcutaneous swellings with hyper-eosinophilia weeks to months after consuming raw seafood should provoke suspicion of gnathostomiasis.

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

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.

Spontaneous cure after natural infection with Gnathostoma turgidum (Nematoda) in Virginia opossums (Didelphis virginiana).

Seasonality of the nematode Gnathostoma turgidum in Virginia opossums (Didelphis virginiana) in the wild has been reported; however, the mechanisms involved in deworming are unknown. We monitored the parasitologic and biologic changes in four Virginia opossums naturally infected with G. turgidum by coproparasitologic examination and abdominal ultrasonography. Eggs became detectable in the feces of opossums in May, peaked in July and August, and suddenly decreased in October. Adults of G. turgidum were expelled in the feces mainly in September. Ultrasonography of the liver showed slight damage during May. Lesions in the stomach appeared in April and persisted until September. The abnormalities of the liver and stomach were resolved in November. These data suggest that G. turgidum is likely expelled as a result of host immunologic mechanisms, although termination of a natural life span cannot be definitively excluded.

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.

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.

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.

Intraocular gnathostomiasis: report of a case and review of literature.

Intraocular gnathostomiasis is a rare parasitic infection caused by the third-stage larvae of spiruroid nematode Gnanthostoma spp. seen mostly in tropical and subtropical regions. It is a food-borne zoonosis caused by ingestion of raw or undercooked freshwater fish, amphibians, reptiles, birds, and mammals, all of which are known to harbor advanced third-stage larvae of Gnanthostoma spp. To date, 74 cases of intraocular gnathostomiasis have been reported from 12 different countries. Only four countries have reported more than 10 cases each, and India shares the rare distinction of being one of them, with 14 cases. Surprisingly, not a single case of cutaneous gnanthostomiasis has ever been reported from India. We present one such case of intraocular gnathostomiasis in a 41-year-old male who presented with an actively motile worm attached to the iris, and we review the pertinent literature of all such cases reported from India.

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.