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.
Animal Structures/parasitology ; Animals ; Fish Diseases/*parasitology ; Gnathostoma/anatomy & histology/classification/*isolation & purification ; Gnathostomiasis/parasitology/*veterinary ; Microscopy ; Myanmar ; Smegmamorpha/*parasitology

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).
Adult ; Aged ; Animals ; Antibodies, Helminth/*blood ; Antigens, Helminth/diagnostic use ; Brain/radiography ; Female ; Gnathostoma/immunology/*isolation & purification ; Gnathostomiasis/*diagnosis/*parasitology ; Humans ; Immunoblotting ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Serum/immunology ; Subarachnoid Hemorrhage/*diagnosis/*etiology ; Thailand ; Tomography, X-Ray Computed

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.
Adult ; Animals ; Antibodies, Helminth/blood ; Antigens, Helminth/*diagnostic use/genetics/isolation & purification ; Central Nervous System Parasitic Infections/*diagnosis/parasitology ; Gnathostoma/enzymology/immunology/*isolation & purification ; Gnathostomiasis/*diagnosis/parasitology ; Healthy Volunteers ; Humans ; Immunoblotting/methods ; Immunoglobulin G/blood ; Matrix Metalloproteinases/*diagnostic use/genetics/isolation & purification ; Parasitology/*methods ; Prospective Studies ; Recombinant Proteins/diagnostic use/genetics/isolation & purification ; Sensitivity and Specificity ; Serologic Tests/methods ; Thailand

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).
Animals ; Anthelmintics/therapeutic use ; Antibodies, Helminth/immunology ; China ; Eosinophilia/diagnosis/drug therapy/immunology/*parasitology ; Female ; Gnathostoma/immunology/*isolation & purification ; Gnathostomiasis/diagnosis/drug therapy/immunology/*parasitology ; Humans ; Middle Aged ; Skin Diseases, Parasitic/diagnosis/drug therapy/immunology/*parasitology

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.
Animals ; Aquaculture ; Fish Diseases/*epidemiology/*parasitology ; Gnathostoma/*isolation & purification ; Gnathostomiasis/epidemiology/parasitology/*veterinary ; Larva ; Liver/parasitology ; Parasite Load ; Prevalence ; Seasons ; Smegmamorpha/*parasitology ; Thailand/epidemiology

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.
Adolescent ; Animals ; Blotting, Western ; Fundus Oculi ; Gnathostoma/*isolation & purification ; Gnathostomiasis/*diagnosis/parasitology ; Humans ; Male ; Retinal Diseases/*diagnosis/parasitology ; Travel ; Vietnam

A survey was performed to find out the intermediate hosts of Gnathostoma nipponicum in Jeju-do (Province), the Republic of Korea. In August 2009 and 2010, a total of 82 tadpoles, 23 black-spotted pond frogs (Rana nigromaculata), 7 tiger keelback snakes (Rhabdophis tigrinus tigrinus), 6 red-tongue viper snakes (Agkistrodon ussuriensis), and 2 cat snakes (Elaphe dione) were collected in Jeju-do and examined by the pepsin-HCl digestion method. Total 5 gnathostome larvae were detected in 3 (50%) of 6 A. ussuriensis, 70 larvae in 3 of 7 (42.9%) R. tigrinus tigrinus, and 2 larvae in 2 of 82 (8.7%) frogs. No gnathostome larvae were detected in tadpoles and cat snakes. The larvae detected were a single species, and 2.17x0.22 mm in average size. They had characteristic head bulbs, muscular esophagus, and 4 cervical sacs. Three rows of hooklets were arranged in the head bulbs, and the number of hooklets in each row was 29, 33, and 36 posteriorly. All these characters were consistent with the advanced third-stage larvae of G. nipponicum. It has been first confirmed in Jeju-do that R. nigromaculata, A. ussuriensis, and R. tigrinus tigrinus play a role for intermediate and/or paratenic hosts for G. nipponicum.
Animals ; Gnathostoma/*isolation & purification/ultrastructure ; Gnathostomiasis/parasitology/*veterinary ; Host Specificity ; Humans ; Larva ; Ranidae/*parasitology ; Republic of Korea ; Snakes/*parasitology

Adult gnathostomes were discovered in the stomach of the Jeju weasel, Mustela sibilica quelpartis, road-killed in Jeju-do (Province). Their morphological characters were examined to identify the species. Total 50 gnathostome adults were collected from 6 out of 10 weasels examined. In infected weasels, 4-6 worms were grouped and embedded in each granulomatous gastric tumor, except 1 weasel. Male worms were 25.0x1.4 mm in average size, and had a tail with pedunculate papillae, a spicule, and minute tegumental spines. Females were 40.0x2.5 mm in average size, and had a tail without tegumental spines. Pointed and posteriorly curved hooklets were arranged in 8-10 rows on the head bulb. Tegumental spines were distributed from behind the head bulb to the middle portion of the body. The spines were different in size and shape by the distribution level of the body surface. Fertilized eggs were 65.5x38.9 microm in average size, and had a mucoid plug at 1 pole. These gnathostomes from Jeju weasels were identified as Gnathostoma nipponicum Yamaguti, 1941. By the present study, it was confirmed for the first time that G. nipponicum is distributed in Jeju-do, the Republic of Korea, and the Jeju weasel, M. sibilica quelpartis, plays a crucial role for its definitive host.
Animals ; Female ; Gnathostoma/anatomy & histology/classification/*isolation & purification/*pathogenicity ; Male ; Mustelidae/*parasitology ; Republic of Korea ; Stomach/parasitology

Human Gnathostoma hispidum infection is extremely rare in the world literature and has never been reported in the Republic of Korea. A 74-year-old Korean man who returned from China complained of an erythematous papule on his back and admitted to our hospital. Surgical extraction of the lesion and histopathological examination revealed sections of a nematode larva in the deep dermis. The sectioned larva had 1 nucleus in each intestinal cell and was identified as G. hispidum. The patient recalled having eaten freshwater fish when he lived in China. We designated our patient as an imported G. hispidum case from China.
Aged ; Animals ; China ; Gnathostoma/*isolation & purification/physiology ; Gnathostomiasis/*parasitology ; Humans ; Male ; Republic of Korea ; Travel

To examine the infection status of freshwater fish with Gnathostoma spp. larvae in Myanmar, we purchased 15 snakeheads, Channa striatus, from a local market in a suburban area of Naypyidaw, the new capital city. Two larval gnathostomes were collected using an artificial digestion technique, and observed by a light microscope and a scanning electron microscope. The size of an intact larva was 2.65 mm long and 0.32 mm wide. The characteristic morphology of the larvae included the presence of a long esophagus (0.80 mm long), 2 pairs of cervical sacs (0.43 mm long), and a characteristic head bulb with 4 rows of hooklets. The number of hooklets in the 1st, 2nd, 3rd, and 4th row was 45, 48, 50, and 52, respectively. Based on these morphological characters, the larvae were identified as the advanced 3rd-stage larvae of Gnathostoma spinigerum. This is the first report of detection of G. spinigerum 3rd-stage larvae in the central part of Myanmar. Our study suggests that intake of raw meat of snakehead fish in Myanmar may result in human gnathostomiasis.
Animals ; Fish Diseases/parasitology ; Gnathostoma/*isolation & purification/ultrastructure ; Larva/ultrastructure ; Myanmar ; Perciformes/*parasitology ; Spirurida Infections/parasitology/*veterinary