Gnathostoma infection after ingestion of raw fish is a probable cause of eosinophilic meningitis in the Brazilian Amazon.

We report a case of eosinophilic meningitis associated with the ingestion of raw fish (Cichla sp.) from the Brazilian Amazon, likely caused by Gnathostoma. A 36-year-old male visited Juruena river on a fishing trip. After 50 days, the patient presented with an intense frontal headache. A cerebrospinal fluid examination revealed 63% eosinophilia. Another individual who ingested raw fish developed linear dermatitis on the abdominal wall. Anti-Gnathostoma serum antibodies were detected, and the patient made a full recovery after treatment with corticosteroids and albendazole. To date, autochthonous Gnathostoma spp. infections in Latin American countries have only caused linear panniculitis. This report raises awareness of gnathostomiasis-causing meningitis.

A case of vocal cord gnathostomiasis diagnosed with sectional morphologies in a histopathological specimen from a Chinese woman living in Korea.

This study aimed to describe a rare case of gnathostomiasis in the vocal cord. A 54-year-old Chinese woman living in Korea visited with a chief complaint of voice change at the outpatient department of otorhinolaryngology in Hallym Sacred Heart Hospital, Hallym University on August 2, 2021. She had eaten raw conger a few weeks before the voice change developed, but her medical history and physical examinations demonstrated neither gastrointestinal symptoms nor other health problems. A round and red cystic lesion, recognized in the anterior part of the right vocal cord, was removed using forceps and scissors through laryngeal microsurgery. The histopathological specimen of the cyst revealed 3 cross-sections of a nematode larva in the lumen of the cyst wall composed of inflammatory cells and fibrotic tissues. They differ in diameter, from 190 µm to 235 µm. They showed characteristic cuticular layers with tegumental spines, somatic muscle layers, and gastrointestinal tracts such as the esophagus and intestine. Notably, intestinal sections consisted of 27-28 lining cells containing 0-4 nuclei per cell. We tentatively identified the nematode larva recovered from the vocal cord cystic lesion as the third-stage larva of Gnathostoma, probably G. nipponicum or G. hispidum, based on the sectional morphologies.

Intracameral Gnathostomiasis: A Case Report and Literature Review.

PURPOSE: The purpose of this article is to report a case of ocular gnathostomiasis presenting with acute anterior uveitis and uveitis glaucoma. METHODS: observational case report and literature review. RESULTS: A 56-year-old Thai male was referred to a tertiary eye center with acute anterior uveitis and uveitis glaucoma in the right eye. A nematode was found in the right anterior chamber. Surgical removal of the nematode was successfully performed. Gnathostoma spinigerum was the nematode identified on pathological examination. CONCLUSIONS: Early detection of the parasite and timely surgical removal is the key to the management of ocular gnathostomiasis.

Protein and antigen profiles of third-stage larvae of Gnathostoma spinigerum assessed with next-generation sequencing transcriptomic information.

Gnathostomiasis is a food-borne zoonotic disease that can affect humans who eat improperly cooked meat containg infective third-stage larvae. Definitive diagnosis is through larval recovery. However, this is an invasive technique and is impractical if the larvae have encysted in inaccessible areas of the body. Antigen or antibody detection might be more interesting techniques for diagnosis. Proteomic could elucidate diagnostic markers and improve our understanding of parasite biology. However, proteomic studies on Gnathostoma spinigerum are hampered by the lack of a comprehensive database for protein identification. This study aimed to explore the protein and antigen profiles of advanced third-stage G. spinigerum larvae (aL3Gs) using interrogation of mass spectrometry data and an in-house transcriptomic database for protein identification. Immunoproteomic analysis found 74 proteins in 24-kDa SDS-PAGE bands, which is size-specific for the immunodiagnosis of gnathostomiasis. Moreover, 13 proteins were found in 2-DE 24-kDa bands. The data suggest that collagenase 3, cathepsin B, glutathione S-transferase 1, cuticle collagen 14, major antigen, zinc metalloproteinase nas-4, major egg antigen, peroxiredoxin, and superoxide dismutase [Cu-Zn] may be good candidates for novel human gnathostomiasis diagnostic assays. These findings improve our understanding of the parasite's biology and provide additional potential targets for novel therapeutics, diagnostics, and vaccines.

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.

Evaluation of immunodiagnostic tests for human gnathostomiasis using different antigen preparations of Gnathostoma spinigerum larvae against IgE, IgM, IgG, IgG1-4 and IgG1 patterns of post-treated patients.

OBJECTIVES: The aims of the study were two-fold: (1) antigen (Ag) preparation and evaluation of three antigens of Gnathostoma spinigerum infective larvae (GsL3), crude somatic antigen (CSAg), excretory-secretory antigen (ESAg) and partially purified antigens (namely P1Ag, P2Ag and P3Ag) to differentiate IgE, IgG, IgG1-4 and IgM for human gnathostomiasis diagnosis; and (2) application of the selected ELISA for following up stored sera of patients treated with ivermectin (IVM) and albendazole (ABZ). METHODS: Different antigens were analysed by antibodies of gnathostomiasis cases, other parasite infections and healthy controls using indirect ELISA to differentiate IgE, IgG, IgG1-4 and IgM. Then, prominent antigen and immunoglobulin were used in antibody predictions of gnathostomiasis cases treated with albendazole or ivermectin. RESULTS: Sensitivity of all evaluated ELISAs: IgM-, IgG-, IgG1- and IgG4-ELISA, was 100%. IgM-ELISA with CSAg and P3Ag exhibited the highest specificity of 99%. IgG-ELISA with P2Ag resulted in the highest specificity of 92.3%. IgG1-ELISA with P2Ag and P3Ag showed excellent results with 100% specificity. Finally, P2Ag evaluated IgG1 of the followed-up cases with ABZ and IVM. Decreasing antibody IgG1 levels were mostly found in both treatments at Month 9 and long follow-up was over 12 months. A Gnathostoma worm was extracted from each two treated patients. CONCLUSIONS: Using IgG1-ELISA against P2Ag and P3Ag gave excellent results with 100% sensitivity and specificity. These tests can be an alternative to immunoblotting for gnathostomiasis. IgG1 decreased at least 9 months in most cases, so long-term treatment should be performed over 1 year.

Atypical gnathostomiasis-confirmed cutaneous larva migrans, Vietnam.

We reported a case of gnathostomiasis in a 42-year-old woman with an unclear history of eating high-risk foods and had a non-migratory skin lesion, negative serological testing and normal blood eosinophil counts. A diagnosis of gnathostomiasis was based on a live, third-stage Gnathostoma spinigerum larva that was randomly taken from the patient's skin lesion by herself. The presenting case report demonstrates challenges in correctly diagnose cutaneous gnathostomiasis even in endemic countries due to atypical skin lesions, negative serology testing and the absence of eosinophilia and thus, the widely used classic triad of suggestive evidence of gnathostomiasis is not fulfilled.

Evaluation of Rapid IgG4 Test for Diagnosis of Gnathostomiasis.

Human gnathostomiasis is a parasitic disease caused by Gnathostoma nematode infection. A rapid, reliable, and practical immunoassay, named dot immuno-gold filtration assay (DIGFA), was developed to supporting clinical diagnosis of gnathostomiasis. The practical tool detected anti-Gnathostoma-specific IgG4 in human serum using crude extract of third-stage larvae as antigen. The result of the test was shown by anti-human IgG4 monoclonal antibody conjugated colloidal gold. The sensitivity and specificity of the test were both 100% for detection in human sera from patients with gnathostomiasis (13/13) and from healthy negative controls (50/50), respectively. Cross-reactivity with heterogonous serum samples from patients with other helminthiases ranged from 0 (trichinosis, paragonimiasis, clonorchiasis, schistosomiasis, and cysticercosis) to 25.0% (sparganosis), with an average of 6.3% (7/112). Moreover, specific IgG4 antibodies diminished at 6 months after treatment. This study showed that DIGFA for the detection of specific IgG4 in human sera could be a promising tool for the diagnosis of gnathostomiasis and useful for evaluating therapeutic effects.

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.

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.

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

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.

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.