• Parasites, Hosts and Diseases
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• v.53 no.6
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• pp.713-717
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• 2015

A 23-year-old female residing in a village of Cao Bang Province, North Vietnam, visited the Hospital of Hanoi Medical University in July 2013. She felt dim eyes and a bulge-sticking pain in her left eye for some days before visiting the hospital. In the hospital, a clinical examination, an eye endoscopy, and an operation were carried out. A nematode specimen was collected from the eye of this patient. The body of this worm was thin and long and measured $22.0{\times}0.3mm$. It was morphologically suggested as an immature female worm of Angiostrongylus cantonensis. By a molecular method using 18S rRNA gene, this nematode was confirmed as A. cantonensis. This is the first molecular study for identification of A. cantonensis in Vietnam.

• Parasites, Hosts and Diseases
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• v.55 no.3
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• pp.267-285
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• 2017

Angiostrongylus cantonensis invades the central nervous system (CNS) of humans to induce eosinophilic meningitis and meningoencephalitis and leads to persistent headache, cognitive dysfunction, and ataxic gait. Infected mice (nonpermissive host), admittedly, suffer more serious pathological injuries than rats (permissive host). However, the pathological basis of these manifestations is incompletely elucidated. In this study, the behavioral test, histological and immunohistochemical techniques, and analysis of apoptotic gene expression, especially caspase-3, were conducted. The movement and motor coordination were investigated at week 2 post infection (PI) and week 3 PI in mice and rats, respectively. The cognitive impairs could be found in mice at week 2 PI but not in rats. The plaque-like lesion, perivascular cuffing of inflammatory cells, and dilated vessels within the cerebral cortex and hippocampus were more serious in mice than in rats at week 3 PI. Transcriptomic analysis showed activated extrinsic apoptotic pathway through increased expression of TNFR1 and caspase-8 in mice CNS. Immunohistochemical and double-labeling for NeuN and caspase-3 indicated the dramatically increased expression of caspase-3 in neuron of the cerebral cortex and hippocampus in mice but not in rats. Furthermore, western-blotting results showed high expression of cleaved caspase-3 proteins in mice but relatively low expression in rats. Thus, extrinsic apoptotic pathway participated in neuronal apoptosis might be the pathological basis of distinct behavioral dysfunctions in rodents with A. cantonensis infection. It provides the evidences of a primary molecular mechanism for the behavioral dysfunction and paves the ways to clinical diagnosis and therapy for A. cantonensis infection.

• Parasites, Hosts and Diseases
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• v.51 no.6
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• pp.613-619
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• 2013

Angiostrongyliasis, caused by Angiostrongylus cantonensis infection, is a food-borne parasitic disease. Its larvae evoke eosinophilic inflammation in the central nervous system, but can also cause pathological changes in the eyes. Among ocular angiostrongyliasis cases, the incidence of optic neuritis is low and only few sporadic reports exist. Some patients with optic neuritis developed obvious hypopsia or even vision loss, which would seriously influence the quality of life of patients. Prompt treatment of optic neuritis caused by A. cantonensis is the key factor for minimizing the incidence of serious complications of this disease. In this review, we first provide a comprehensive overview of ocular angiostrongyliasis, and then focus on the clinical features of optic neuritis caused by A. cantonensis.

• Parasites, Hosts and Diseases
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• v.54 no.3
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• pp.375-380
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• 2016

Angiostrongyliasis is difficult to be diagnosed for the reason that no ideal method can be used. Serologic tests require specific equipment and are not always available in poverty-stricken zone and are time-consuming. A lateral flow immunoassay (LFIA) may be useful for angiostrongyliasis control. We established a LFIA for the diagnosis of angiostrongyliasis based on 2 monoclonal antibodies (mAbs) against antigens of Angiostrongylus cantonensis adults. The sensitivity and specificity were 91.1% and 100% in LFIA, while those of commercial ELISA kit was 97.8% and 86.3%, respectively. Youden index was 0.91 in LFIA and 0.84 in commercial ELISA kit. LFIA showed detection limit of 1 ng/ml of A. cantonensis ES antigens. This LFIA was simple, rapid, highly sensitive and specific, which opened an alternative approach for the diagnosis of human angiostrongyliasis.

• Parasites, Hosts and Diseases
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• v.51 no.6
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• pp.735-738
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• 2013

Eosinophilic meningitis, caused by the nematode Angiostrongylus cantonensis, is prevalent in northeastern Thailand, most commonly in adults. Data regarding clinical manifestations of this condition in children is limited and may be different those in adults. A chart review was done on 19 eosinophilic meningitis patients aged less than 15 years in Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Thailand. Clinical manifestations and outcomes were reported using descriptive statistics. All patients had presented with severe headache. Most patients were males, had fever, nausea or vomiting, stiffness of the neck, and a history of snail ingestion. Six patients had papilledema or cranial nerve palsies. It was shown that the clinical manifestations of eosinophilic meningitis due to A. cantonensis in children are different from those in adult patients. Fever, nausea, vomiting, hepatomegaly, neck stiffness, and cranial nerve palsies were all more common in children than in adults.

• Parasites, Hosts and Diseases
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• v.57 no.3
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• pp.249-256
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• 2019

Steroids are commonly used in patients with eosinophilic meningitis caused by A. cantonensis infections. The mechanism steroids act on eosinophilic meningitis remains unclear. In this mouse experiments, expressions of 14-3-3 isoform ${\beta}$ and ${\gamma}$ proteins significantly increased in the CSF 2-3 weeks after the infection, but not increasedin the dexamethasone-treated group. Expression of 14-3-3 ${\beta}$, ${\gamma}$, ${\varepsilon}$, and ${\theta}$ isoforms increased in brain meninges over the 3-week period after infection and decreased due to dexamethasone treatment. In conclusion, administration of dexamethasone in mice with eosinophilic meningitis decreased expressions of 14-3-3 isoform proteins in the CSF and in brain meninges.

• Parasites, Hosts and Diseases
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• v.58 no.4
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• pp.387-392
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• 2020

A serological survey was performed using ELISA to estimate the prevalence of tissue and luminal helminthic infections among hospital patients in Hanoi region, Vietnam. An overall seroprevalence of tissue and luminal helminthiases was 64.0% (95% CI 61.2-66.8) among 1,120 patients who visited Hanoi Medical University Hospital, Vietnam in 2018. The highest seroprevalence was observed against Toxocara spp. (59.0%), followed by Strongyloides stercoralis (46.3%), Gnathostoma spp. (25.5%), cysticercus (12.8%), Angiostrongylus cantonensis (10.5%), Fasciola spp. (11.1%), and Clonorchis sinensis (8.7%). Mono-infection by one species (11.1%) was lower than multiple infections (53.0%) (P<0.05). The seroprevalence in males (59.3%) was lower than in females (66.2%) but not statistically significant (P>0.05). Children (<15 years) revealed lower seroprevalence (34.0%) than adults (68.4%), and the age group 51-70 years revealed the highest seroprevalence (76.0%). Among the seropositive patients, eosinophilia (≥8.0%) was noted in 80.2%. The present results suggested active transmission of various tissue and luminal helminths among people in Hanoi, Vietnam.

• Parasites, Hosts and Diseases
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• v.51 no.6
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• pp.633-636
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• 2013

Angiostrongylus cantonensis is a parasitic nematode that needs to develop in different hosts in different larval stages. Freshwater snails, such as Pomacea canaliculata, are the intermediate host, and rats are the definitive host. Periodic shedding of the cuticle (moulting) is an important biological process for the survival and development of the parasite in the intermediate and definitive hosts. However, there are few studies on the cuticle alterations between different stages of this parasite. In this study, we observed the ultrastructural appearance and changes of the cuticle of the 2nd/3rd stage larvae (L2/L3) and the 3rd/4th stage larvae (L3/L4) using a scanning electron microscope. We also first divided L2/L3 into late L2 and early L3. The late L2 lacked alae, but possessed a pull-chain-like fissure. Irregular alignment of spherical particles on the cuticle were noted compared to the L3. Alae appeared in the early L3. The old cuticle turned into a thin filmlike structure which adhered to the new cuticle, and spherical particles were seen regularly arranged on the surface of this structure. Regular rectangular cavities were found on the surface of L3/L4. The caudal structure of L3/L4 was much larger than that of L3, but caudal inflation, such as seen in L4, was not observed. These results are the first to reveal the ultrastructural changes of the cuticle of A. cantonensis before and after moulting of L2/L3 and L3/L4.

• Journal of agricultural medicine and community health
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• v.27 no.2
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• pp.67-73
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• 2002

집쥐가 인체 기생충 전파에 어느 정도의 역할을 하는지 그 양상을 밝히고자 전라북도 남원, 익산지역에서 포획한 집쥐의 체내 기생충 감염상을 조사하였다. 섬진강 상류 남원지역에서 32마리, 만경강 중류 익산지역에서 53마리를 채집하여 총 85마리였고, 종별로는 곰쥐(Rattus rattus) 28마리, 시궁쥐(Rattus norvegicus) 57마리였다. 결과를 요약하면 다음과 같다. 1. 남원, 익산지역의 집쥐 85마리 중 71마리(83.5%)에서 체내 기생충이 검출되었다. 2. 폐장이 회수되었던 집쥐 74마리 중 35마리(47.3%)에서 폐장에 기생하는 조직 기생충인 폐포자충(Pneumocystis carinii)이 검출되었다. 3. 전체 85마리의 가로막에서 선모충(Trichinella spiralis)을 조사하였고, 폐심장 혈관계에서 광동주혈선충(Angiostrongylus cantonensis)을 조사하였으나 한 예도 검출하지 못하였다. 4. 간을 조사한 바 85마리 중 간모세선충(Capillaria hepatica) 22례(25.9%), Taenia taeniaeformis의 유충(Cysticercus fasciolaris) 9례(10.6%), 간흡충(Clonorchis sinensis) 1례(1.2%)가 검출되었다. 5. 장내용물을 조사 한 바 85 마리 중 50례(58.9%)에서 윤충 및 원충이 검출되었다. 윤충은 쥐조충(Hymenolepis diminuta), 극구흡충류(Echinostoma sp.), 쥐요충류(Syphacia sp.), 분신충류(Strongyloides sp.) 등이었고 원충은 대장아메바(Entamoeba coli) 등이었다. 이상의 결과에서 인수공통 질환을 일으킬 수 있는 폐포자충, 쥐조충, 간흡충 등이 집쥐에 감염되어 있어 철저한 집쥐 관리가 요망된다.

• Journal of Environmental Science International
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• v.28 no.1
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• pp.75-84
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• 2019

Cytochrome c oxidase subunit II gene(CO II gene) is subunit of cytochrome oxidase, which is complex IV of mitochondria electron transport system. It has been frequently used in molecular phylogenetic studies because the speed of its DNA variation is faster than that of nucleus. It is especially useful in phylogenetic study of molecular biology in insects. In this study, we cloned and sequenced CO II gene of mitochondria DNA from Rhabditidae family nematode. Our results showed that this gene is comprised of 696 base pairs(bp). In the analysis of similarity of this gene with other known genes of 14 species of nematodes in Rhabditida order, we identified that this gene has high similarity with that of Caenorhabditis briggsae(86.0%) and C. elegans(85.6%) in Rhabditidae family. On the meanwhile, it has very low similarity with that of Angiostrongylus cantonensis(31.8%) in Angiostrongylidae family and Metastrongylus salmi(31.6%) in Metastrongylidae family. Based on the results of this study, we suggest that this nematode is closely related with that of Caenorhabditis genus in Rhabditidae family.