Case Report: The First Direct Evidence of Gnathostoma spinigerum Migration through Human Lung.

Gnathostomiasis is a helminthic infection caused by the third-stage larvae of nematodes of the genus Gnathostoma. The life cycle in humans starts with an enteric phase, with the worm perforating the gastric or intestinal mucosa to reach the peritoneal cavity and migrating through the human body. Subsequent penetration through the diaphragm may produce pleuropulmonary symptoms. We herein present a previously healthy 56-year-old Thai man from Southern Thailand who was an ex-smoker presented with chronic dry cough progressing to hemoptysis after consuming grilled swamp eels and freshwater fish. Chest computed tomography showed consolidation at the lingular segment, and the differential diagnosis was primary lung cancer and pulmonary tuberculosis. The lung tissue biopsied during bronchoscopy displayed segments of organisms with the phenotypic characteristics of Gnathostoma spp., and abundant eosinophils were seen in the alveolar tissue. Gnathostoma spinigerum infection was confirmed by a Western blot assay for G. spinigerum-specific 24-kDa reactive band. The patient received albendazole, and a follow-up chest radiograph revealed improvement in the consolidation in the lung and reduction in hemoptysis. We report the first direct evidence including pathology and immunohistochemistry of Gnathostoma invasion via the human lung, with clinical and radiographic presentations mimicking either malignancy or chronic infection.

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.

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

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.

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.

Case Report: Ocular Gnathostomiasis in Venezuela Most Likely Acquired in Texas.

A 69-year-old male dentist in Caracas, Venezuela, was referred to our Cornea Clinic with a history of pain, photophobia, and blurred vision on his left eye. Routine biomicroscopic examination with a slit lamp showed a worm in the corneal stroma of his left eye. The worm was surgically removed and was identified morphologically as Gnathostoma binucleatum.

Gnathostomiasis: an emerging infectious disease relevant to all dermatologists.

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.

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.

Histopathological changes in the liver and stomach of Didelphis virginiana (Didelphimorphia: Didelphidae) during natural infection with Gnathostoma turgidum (Nematoda: Gnathostomidae).

Gnathostoma turgidum is a nematode parasite that exploits the stomach of Virginian opossums, Didelphis virginiana, in Latin America. The opossum is the definitive host of G. turgidum in the wild. Intrahepatic growth and maturation of the parasite, subsequent migration to the stomach and spontaneous expulsion are common. However, the histopathological lesions caused by G. turgidum are poorly described. A better understanding of the life cycle of this parasite and the pathological changes in natural host-parasite interactions could help to clarify the progression of human infections caused by Gnathostoma binucleatum. The aim of this work was to study morphological changes in the liver and stomach of D. virginiana during natural infection and adult worm expulsion. Three opossums naturally infected with G. turgidum were captured from an endemic area of gnathostomosis. Three uninfected opossums captured from a non-endemic area were used as controls. The opossums were sacrificed at different stages of infection (March, May and December), and a histopathological study of their livers and stomachs was conducted. Injuries in livers were observed by histopathology - areas of necrosis and collagen septa were identified. Parasites caused nodules with necrosis on the periphery of lesions, and collagen fibres were also observed in stomachs. Collagen septa may be caused by antigenic remains of the parasite. Further immunological studies are necessary to verify that stimulation is caused by these factors.

Neurognathostomiasis in a young child in India: A case report.

Eosinophilc meningitis is commonly associated with Angiostrongylus and Gnathostoma infection and has largely been reported from Thailand. We present the first case report of neurognathostomaisis in a pediatric patient from India. A 3.5 year old girl presented with fever, parasthesis, behavioral changes followed by flaccid quadriparesis. Neuroimaging showed haemorrhagic radiculomyelitis with cerebrospinal fluid eosinophilia. Diagnosis of Gnathostoma infection was confirmed serologically and she was treated with anthelminthic drugs and steroids. This report emphasizes the increasing importance of central nervous system helminithic infections as an alternative diagnosis to common infections like neurotuberculosis in developing countries, even in pediatric patients. Increasing intercontinental travel and migration have increased the incidence and importance in the developed world as well.

Eosinophilic meningitis: a case series and review of literature of Angiostrongylus cantonensis and Gnathostoma spinigerum.

Eosinophilic meningitis is defined as the presence of >10 eosinophils/µL in cerebrospinal fluid (CSF) or at least 10% eosinophils in the total CSF leukocyte count. Eosinophilic meningitis has been reported in two case series and two case reports in India till date and has not been reported in children below 15 years of age. We present two children with eosinophilic meningitis with peripheral eosinophilia and the proposed etiologic agents based on the clinical setting and their response to antihelminthic agents.

Pathological and parasitological traits in experimentally infected cats with Gnathostoma binucleatum (Spirurida: Gnathostomatidae).

This study aims to describe some of the unknown pathological and parasitological traits of experimental feline gnathostomosis. Thirteen female cats were orally inoculated with 30 advanced third-stage Gnathostoma binucleatum larvae and were euthanized at various post-infection (p.i.) periods. Clinically, the cats presented with nausea, vomiting, abdominal pain and other nonspecific signs. None of the cats shed eggs in their fecal matter. One cat, euthanized at 6 months p.i., developed a fibrous vascular nodule 2-3 cm in diameter within its gastric wall. The nodule contained caverns filled with mucous and bloody fluid as well as a juvenile worm. The histological characteristics of the nodule were observed, and the morphology of the juvenile worm was revealed using scanning electron microscopy. Another cat, euthanized at 10 months p.i., was found to have a larva within its diaphragm. Infected cats developed increased antibody titers against antigens of G. binucleatum adults and larvae beginning in the first month p.i., and these titers were maintained until the end of the experiment, suggesting the presence of undetected migrating larvae. The low number of cats with parasites and poor development of the parasites found suggest that cats have a low susceptibility to infection by G. binucleatum and cast doubt on the importance of domestic cats in maintaining the biological cycle of this parasite in nature.

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.

Cutaneous gnathostomiasis: report of 6 cases with emphasis on histopathological demonstration of the larva.

BACKGROUND: Cutaneous gnathostomiasis is an emerging food-borne parasitic zoonosis. Histopathological demonstration of the larva on random biopsy specimen of erythematous plaques is infrequent because of its migrating nature. OBJECTIVE: We sought to determine whether medical treatment with albendazole or ivermectin increases the diagnostic yield of skin biopsy specimen. METHODS: A retrospective chart review was conducted in a private dermatology practice in Lima, Peru. Cases with a clinical diagnosis of nodular migratory panniculitis and pathological diagnosis of eosinophilic panniculitis or gnathostomiasis were reviewed. Only cases with definitive diagnosis confirmed by histopathology or parasite isolation were included in the study. RESULTS: A definitive diagnosis of gnathostomiasis was rendered in 6 of 55 reviewed cases. Histopathological or gross identification of the nematode's larva was made obtaining a biopsy specimen of papules or pseudofuruncles that developed after oral antiparasitic treatment. LIMITATIONS: This is a retrospective case series study and no serologic testing was available. CONCLUSION: Biopsy of a papule or pseudofuruncle subsequent to oral treatment increases the likelihood of demonstrating the larva on skin biopsy specimen, which allows definitive diagnosis and may have therapeutic benefit.

A rare case of cutaneous larva migrans due to Gnathostoma sp.

A 28-year-old lady presented with recurrent erythematous skin lesions in different parts of the body for 3 months. There were several episodes of worm coming out of the lesions. Examination of the worms in the parasitology laboratory revealed it to be a larva of Gnathostoma sp. She was advised treatment with Albendazole for 21 days, and there was no recurrence of lesions.

A comparative study of neuroimaging features between human neuro-gnathostomiasis and angiostrongyliasis.

Gnathostoma spinigerum and Angiostrongylus cantonensis are human parasites that can cause neurological symptoms. The human diseases produced by these parasites can usually be differentiated by clinical symptoms. The aim of this study was to report neuroimaging abnormalities detected with computed tomography (CT) and MR in patients with gnathostomiasis and angiostrongyliasis. We enrolled 15 and 12 patients with serologically proven gnathostomiasis and angiostrongyliasis, respectively, who had brain or spinal imaging done. The neuro-gnathostomiasis group had significantly more patients with intracerebral hemorrhage and myelitis patterns. The angiostrongyliasis group had no specific findings and most patients had normal CT brain images. The variety of neuroimaging findings is shown here. This study emphasizes that neuroimaging studies may be useful to differentiate gnathostomiasis and angiostrongyliasis particularly in patients with indistinct clinical presentations.

Gnathostomiasis in a patient who frequently consumes sushi.

A 45-year-old woman presented for evaluation of a solitary pruritic nodule on the abdomen that suddenly appeared 3 weeks before. She was healthy without a significant medical history, travel history, exposures, medications, or pets. She reported that she consumed sushi at least weekly in the city of San Francisco. A punch biopsy revealed a superficial and deep perivascular and interstitial infiltrates consisting of lymphocytes, plasma cells, and many eosinophils. Most notably, there was a parasite centered in the reticular dermis with prominent lateral chords, a well-developed muscular esophagus, and an intestine that contained a brush border and multinucleate cells. Evaluation of these histological sections by the Centers for Disease Control and Prevention determined the parasite to be a nematode of the genus Gnathostoma. The patient underwent a systemic work-up for gnathostomiasis, including imaging, and no other abnormalities were found. She completed a 3-week course of albendazole and has remained asymptomatic since the biopsy of her abdominal lesion. Although gnathostomiasis is often a systemic illness, this patient did well with apparently only localized cutaneous disease. Gnathostomiasis should be considered in patients who present with nonspecific papules and nodules, especially when there is a history of frequent consumption of raw fish.

Neurognathostomiasis, a neglected parasitosis of the central nervous system.

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.

Gnathostoma binucleatum: pathological and parasitological aspects in experimentally infected dogs.

Lesions and antibody kinetics produced by inoculation of Gnathostoma binucleatum larvae into dogs are described, as well as the morphology of the recovered parasites. In four out of five infected bitches parasite phases were found in the stomach. Only one bitch eliminated eggs and adult parasite phases in feces. In this bitch, the prepatency period lasted 22 weeks and the patency period 14 weeks. Necropsy results showed a copiously vascularized 8-cm diameter fibrous nodule lodged in the greater curvature of the stomach. Two bitches that eliminated no eggs showed 1- to 2-cm diameter nodules on the gastric wall, with five juvenile phases in each. One bitch that eliminated no eggs and exhibited no gastric nodules showed juvenile parasites on the gastric wall. Results confirm dogs as definitive hosts of this parasite. New data on the pathological and parasitological aspects of canine gnathostomosis are presented.