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 22.0x0.3 mm. 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.
Angiostrongylus cantonensis/classification/*genetics/*isolation & purification ; Animals ; Base Sequence ; Eye/parasitology ; Eye Diseases/diagnosis/*parasitology ; Female ; Humans ; Molecular Sequence Data ; Strongylida Infections/diagnosis/*parasitology ; Vietnam ; Young Adult

BACKGROUNDAngiostrongyliasis cantonensis is a worldwide-existing parasitic disease. However, the relevant reports on its radiological appearances are limited. In this study, we investigated magnetic resonance imaging (MRI) features of eosinophilic meningoencephalitis in a group of consecutive patients caused by human infection with Angiostrongylus cantonensis after eating freshwater snails.

METHODSWe performed brain MR imaging on 74 patients with angiostrongyliasis cantonensis. The scanner was a 0.5T unit. For each patient MR pulse sequences of SE T1-weighted image (T1WI) and FSE T2-weighted image (T2WI) were used. After intravenous administration of gadolinium chelate (Gd-DTPA) repeated T1-weighted images were obtained. MRI features of the lesions in the brain and meninges were analyzed and recorded after observing initial and follow-up MR images. The classification of the types of angiostrongyliasis cantonensis infection was done on the basis of locations of the disorders.

RESULTSForty-one (55%) normal and 33 (45%) abnormal MRI appearances in the brain were found. According to locations of the disorders, the types of angiostrongyliasis cantonensis infection were determined as follows: seventeen cases of type meningitis, three of type myeloencephalitis, one of type neuritis and twelve of mixed type (eight of type ventriculitis and five of type pneumonitis were among them). In type meningitis, abnormal leptomeningeal enhancement was visualized. In type myeloencephalitis, lesions in the brain parenchyma may have iso- or slightly low signal intensity on T1WI and high signal intensity on T2WI. Enhanced nodules in various shapes were shown on gadolinium-enhanced T1WI, a few lesions appeared as crescent enhancements and some lesions did not reveal abnormal enhancement. Other than brain lesions, an enhanced nodule was seen in the cervical spinal cord in one patient. In type ventriculitis, brain ventricular enlargement was demonstrated. In type neuritis, a nodule and abnormal enhancement in the right optic nerve was revealed. In type pneumonitis, patchy ground-glass opacity and consolidative lesions at the periphery of the lungs were seen. Follow-up results indicated that most lesions in the brain could resolve in 2 to 8 weeks.

CONCLUSIONSAngiostrongyliasis cantonensis presented as both single type and mixed type. Nodular enhancing lesions in the brain and/or linear enhancement in the leptomeninges were the main findings, while crescent enhancement would be the characteristic sign of the disease on gadolinium-enhanced T1WI. Focal edematous changes without contrast enhancement in the brain could be seen on MRI in some cases.

Adolescent ; Adult ; Angiostrongylus cantonensis ; Animals ; Eosinophilia ; diagnosis ; etiology ; Female ; Humans ; Magnetic Resonance Imaging ; methods ; Male ; Meningoencephalitis ; diagnosis ; etiology ; Middle Aged ; Snails ; parasitology ; Strongylida Infections ; complications

OBJECTIVETo analyze the diagnostic value of larval excretory-secretory antigen in Angiostrongylus cantonensis (LESA) infection.

METHODSA.cantonensis larvae harvested from mice brain were cultured in vitro. The LESA and the adult worm antigens of A.cantonensis (AWA) were collected and analyzed using SDS-PAGE and Western blotting. Two ELISA systems were established using the two antigens (LESA-ELISA and AWA-ELISA) to detect the serum spectra from different sources.

RESULTSSDS-PAGE and Western blotting displayed fewer protein and antigen bands for LESA than for the adult antigen. Two distinct bands of LESA (with relative molecular masses of 40 000 and 26 000) showed reactivity with the sera from patients with A. cantonensis infection. The serum levels of IgG and IgM antibodies to LESA increased at the beginning of infection in mice, reaching the peak on day 5 after infection and decreased on day 10. Compared with AWA-ELISA, LESA-ELISA showed a lower seropositive ratio in suspected patients with A.cantonensis, with also a lower cross-positive ratio in patients with schistosomiasis and clonorchis sinensis.

CONCLUSIONLESA possesses fewer antigen reaction bands than AWA. Although with a slightly lower positive ratio than AWA, LESA has a higher specificity for detecting serum antibodies in suspected cases of A.cantonensis infection, and therefore shows a potential for the diagnosis of angiostrongyliasis especially in the early stage and in current infection.

Angiostrongylus cantonensis ; immunology ; Animals ; Antigens, Helminth ; immunology ; Enzyme-Linked Immunosorbent Assay ; Humans ; Larva ; immunology ; Mice ; Mice, Inbred BALB C ; Rats ; Rats, Sprague-Dawley ; Strongylida Infections ; diagnosis ; parasitology

OBJECTIVETo provide scientific basis for angiostrongyliasis cantonensis control and prevention in Beijing.

METHODSDescriptive epidemiological method was used to analyze angiostrongyliasis cantonensis reported from June to September in 2006.

RESULTS141 cases were treated at the Beijing Friendship Hospital with the peak in July (61 cases) and August (68 cases). All patients had dined at the same restaurant in Beijing city and they ate undercooked Pomacea canaliculata or related eatables. The source of Pomacea canaliculata was from Guilin in Guangxi. Major manifestations would include fever (56.79%), headache (93.83%), neck stiffness (100%), and skin paresthesia (77.78%). Some cases had significant eosinophil increase in peripheral blood picture and cerebrospinal fluid respectively.

CONCLUSIONThe source of infection related to angiostrongyliasis cantonensis was clear, suggesting that the improvement of restaurant sanitation and on awareness of personal hygiene were important preventive and control measures on angiostrongyliasis cantonensis.

Adolescent ; Adult ; Aged ; Angiostrongylus cantonensis ; pathogenicity ; Animals ; China ; epidemiology ; Female ; Humans ; Male ; Middle Aged ; Strongylida Infections ; diagnosis ; epidemiology ; parasitology ; Young Adult

OBJECTIVETo identify antigens which may help evaluate the therapeutic effect of angiostrongyliasis from adult worm antigen of Angiostrongylus cantonensis.

METHODSThe adult worm antigens of A. cantonensis were analyzed by Western blotting with the sera of rats infected with A. cantonensis before and after treatment. The sera of rats were tested by enzyme-linked immunosorbent assay (ELISA).

RESULTSThe antigens with relative molecular mass between 38,000 and 78,000 reacted not only with the sera of rats before treatment, but also with that after treatment. The antigens with M(r) between 190,000 and 17,000 reacted with the sera of rats before treatment but not with that after treatment; those with M(r) between 32,000 and 24,000 antigens strongly reacted with the former, but the reaction became much weakened with the latter. The AC32-IgG antibody appeared earlier than the AC-IgG, and disappeared rapidly after treatment. Six of the 10 treated rats became negative for AC-IgG as found by ELISA.

CONCLUSIONThe antigens of adult worm antigen of A. cantonensis with M(r) of 190,000, 32,000, 24,000, 17,000 and 16,000 may serve as candidate antigens for therapeutic effect evaluation of angiostrongyliasis.

Angiostrongylus cantonensis ; immunology ; isolation & purification ; Animals ; Antibodies, Helminth ; blood ; Antigens, Helminth ; blood ; immunology ; isolation & purification ; Blotting, Western ; Enzyme-Linked Immunosorbent Assay ; Rats ; Rats, Sprague-Dawley ; Strongylida Infections ; diagnosis ; immunology ; parasitology