The use of circulating cathodic antigen rapid test and serology for diagnosis of active Schistosoma mansoni infection in migrants in Italy, a non-endemic country: a cross sectional study

ABSTRACT Diagnosis of schistosomiasis in migrants coming from endemic areas can be difficult, especially in asymptomatic subjects. Light-intensity disease, in fact, may be missed due to the low sensitivity of the stool microscopy and serologic testing cannot distinguish between a resolved infection and an active infection in patients who have been infected and treated in the past, because specific antibodies can persist despite cure. We describe a cross-sectional study conducted on 82 migrants tested for Schistosoma mansoni on single blood (anti-schistosome antibodies, total IgE) and urine [point-of-care (POC) circulating-cathodic-antigen (CCA) test] samples. A positive POC-CCA test (active infection) resulted in two untreated patients with a positive serology while all patients (n = 66) with a past infection showed a negative POC-CCA test. POC-CCA urine test in combination with serology may be helpful in rapidly differentiate active from past S. mansoni infection in migrants coming from endemic areas.

Detección de coproantígenos de Echinococcus granulosus en canes de trabajadores de camales y comercializadores de vísceras en Lima metropolitana / Detection of stool antigens of Echinococcus granulosus in dogs belonging to slaughterhouse workers and offal merchants in Metropolitan Lima

RESUMEN Objetivo Demostrar la presencia de Echinoccocus granulosus en el hospedero definitivo en la ciudad de Lima, Perú, mediante la detección de antígenos del parásito en heces de canes pertenecientes a trabajadores y comercializadores de vísceras de centros de beneficio autorizados en Lima metropolitana. Métodos Se recolectaron muestras de heces de 58 canes, que fueron evaluadas utilizando la técnica coproELISA para detectar antígenos secretorio/excretorio de E. granulosus. Mediante una encuesta se obtuvo información sobre las prácticas de alimentación y el manejo de las mascotas. Resultados El 13,8% (8/58) de canes fue positivo a E. granulosus. En 27,8% (5/18) de los hogares se encontró al menos un animal positivo y se estimó que en las familias que tenían más de cuatro canes las posibilidades de encontrar al menos uno positivo eran mayores. En todos los hogares con al menos un can positivo sus mascotas se alimentaban con vísceras. El 94,4% (17) de los participantes no tenía conocimiento de las formas de contagio de la equinococosis. Conclusiones Los resultados muestran la presencia de hospederos definitivos en la zona urbana de Lima y subrayan la necesidad de aumentar la difusión de las prácticas para evitar la transmisión del parasito.

ABSTRACT Objective To demonstrate the presence of Echinoccocus granulosus in the definitive host in the city of Lima, Perú, by detecting parasite antigens in the stool of dogs belonging to offal handlers and merchants in authorized slaughterhouses in Metropolitan Lima. Methods Stool samples were collected from 58 dogs and examined using the coproELISA technique for the detection of secretory/excretory antigens of E. granulosus. A survey was conducted to obtain information on pet feeding and handling practices. Results Positivity to E. granulosus was detected in 13.8% (8/58) of the dogs. In 27.8% (5/18) of the homes, at least one animal showed positivity, and in families that had more than four dogs the chances of finding positivity in at least one dog were higher (P < 0.05). In all homes where at least one dog tested positive the pets were fed on offal. Of study participants, 94.4% (17) knew nothing about the routes of transmission of hydatid disease. Conclusions Results show the presence of definitive hosts in the urban area of Lima and underscore the need to more widely disseminate practices for the prevention of parasite transmission.

Perfil proteico da hemolinfa de Biomphalaria glabrata e linhagens de B. straminea, frente à exposição ao Schistosoma mansoni / Protein profile of hemolymph of Biomphalaria glabrata and strains of B. straminea, against the exposure to the Schistosoma mansoni

O gênero Biomphalaria possui espécies de grande relevância médica uma vez que atuam como hospedeiros intermediários naturais do parasita Schistosoma mansoni, causador da esquistossomose. Dentro desse gênero de moluscos, três espécies são tidas como hospedeiros naturais do parasita, Biomphalaria glabrata, B. straminea e B. tenagophila. O perfil de suscetibilidade à infecção por S. mansoni dentro do gênero é muito variado e muitas pesquisas buscam elucidar a dinâmica da relação parasita-hospedeiro intermediário na finalidade de criar novas medidas de controle da doença. Por isso, esse estudo tem como objetivo determinar o perfil bidimensional de proteínas que podem estar envolvidas na resposta imune contra o S. mansoni comparando duas espécies com diferentes perfis de susceptibilidade B. glabrata, B. straminea além de uma refratária ao S. mansoni, a B. straminea R3. Para isso, os caramujos de cada espécie foram divididos em dois grupos: Infectado, expostos aos miracídios do S. mansoni; e Controle, submetidos ao estresse do processo de infecção livre de miracídios. A hemolinfa foi retirada 24 horas após a exposição. Foi feito o extrato proteico total e determinada a concentração das proteínas totais para cada grupo investigado. As proteínas foram separadas por eletroforese bidimensional onde foi obtido o ponto isoelétrico e peso molecular de todos os spots nos géis...

The Biomphalaria has species of great medical relevance since that act as natural intermediate hosts of the parasite Schistosoma mansoni, which causes schistosomiasis. Within this kind of mollusks, three species are considered natural hosts of the parasite, Biomphalaria glabrata, B. stramineaand B. tenagophila. The profile of usceptibility to S. mansoni infection within the genre is very varied and many studies seek to elucidate the dynamics of host-parasite relationship intermediary in order to create new disease control easures. Therefore, this study aims to determine the two-dimensional profile of proteins that may be involved in the immune response against S. mansonicomparing two species with different susceptibility profiles B. glabrata, B. straminea and a refractory to S. mansoni, B. straminea R3. For that, the snails of each species were divided into two groups: Infected exposed to iracidia of S. mansoni; and control, subjected to stress the miracidia free infection process. The hemolymph was removed 24 hours after exposure. It was made the total protein extract and determined the concentration of total protein for each group investigated. Proteins were separated by two-dimensional electrophoresis was obtained where the isoelectric point and molecular weight of all the spots in the gels...

Pulmonary Toxocariasis Mimicking Invasive Aspergillosis in a Patient with Ulcerative Colitis

A 45-year-old-male who had underlying ulcerative colitis and presented with fever and dry cough. Initially, the patient was considered to have invasive aspergillosis due to a positive galactomannan assay. He was treated with amphotericin B followed by voriconazole. Nevertheless, the patient deteriorated clinically and radiographically. The lung biopsy revealed eosinophilic pneumonia, and ELISA for Toxocara antigen was positive, leading to a diagnosis of pulmonary toxocariasis. After a 10-day treatment course with albendazole and adjunctive steroids, the patient recovered completely without any sequelae. Pulmonary toxocariasis may be considered in patients with subacute or chronic pneumonia unresponsive to antibiotic agents, particularly in cases with eosinophilia.

An Outbreak of Trichinosis with Molecular Identification of Trichinella sp. in Vietnam

The 5th outbreak of trichinosis occurred in a mountainous area of North Vietnam in 2012, involving 24 patients among 27 people who consumed raw pork together. Six of these patients visited several hospitals in Hanoi for treatment. Similar clinical symptoms appeared in these patients within 5-8 days after eating infected raw pork, which consisted of fever, muscle pain, difficult moving, edema, difficult swallowing, and difficult breathing. ELISA revealed all (6/6) positive reactions against Trichinella spiralis antigen and all cases showed positive biopsy results for Trichinella sp. larvae in the muscle. The larvae detected in the patients were identified as T. spiralis (Vietnamese strain) by the molecular analysis of the mitochondrial cytochrome c oxidase subunit III (cox3) gene.

Estandarización de la técnica de Western blot para el diagnóstico de la fasciolosis humana utilizando antígenos de excreción-secreción de Fasciola hepática / Western blot technique standardization of the diagnosis of human fasciolosis using Fasciola hepatica excreted-secreted antigens

Objetivos. Evaluar la eficacia de la técnica de electroinmunotransferencia (EITB) o Western blot utilizando antígenos de excreción-secreción de las formas adultas de Fasciola hepatica (Fh E/S Ag) para el diagnóstico de la fasciolosis humana. Materiales y métodos. Los antígenos fueron obtenidos a las 18 horas de incubación en medio Minimum Essential Eagle y preparados a la concentración proteica de 0,15 ug/uL; los cuales, al ser enfrentados con un pool de sueros de pacientes con fasciolosis confirmada por el hallazgo de huevos del parásito en las heces, se detectaron los antígenos de 10, 12, 17, 23, 27, 30, 36, 43, 66 y 136 KDa, con los cuales se desarrolló la técnica de Western blot. La sensibilidad se evaluó empleando sueros de 67 pacientes con fasciolosis, y la especificidad con sueros de 57 pacientes con otras parasitosis y diez sueros de personas no parasitadas. Resultados. De los 67 sueros, 64 reaccionaron con la banda de 23 KDa y 61 con la banda de 17KDa. Estas dos bandas no fueron detectadas por ninguno de los sueros de pacientes con otras parasitosis, ni de personas no parasitadas, siendo por ello consideradas como específicas y diagnósticas. Conclusiones. La sensibilidad de la prueba, utilizando las bandas de 17 y 23 KDa, fue de 95,5 por ciento cuando se presenta reacción positiva en una o en las dos bandas, siendo la especificidad para estos dos antígenos de 100 por ciento con un valor predictivo positivo de 100 por ciento y un valor predictivo negativo de 95,71 por ciento.

Objectives. To evaluate the performance of the enzyme-linked immunoelectrotransfer blot assay (EITB, Western blot) using excretory/secretory antigens from adult forms of Fasciola hepatica (Fh E/S Ag) for the diagnosis of human fasciolosis. Materials and methods. Antigens were obtained after 18 hours of incubation in culture medium Minimum Essential Eagle, prepared at a protein concentration of 0.15 ug/uL and run against a pool of sera of patients with proven fasciolosis (confirmed by the finding of parasite eggs in the stool microscopy). Antigens of 10, 12, 17, 23, 27, 30, 36, 43, 66 and 136 kDa were detected and used to develop the Western blot technique. The sensitivity was evaluated using sera from 67 fasciolosis patients, and the specificity using sera from 57 patients with other parasitic diseases, and 10 from healthy individuals. Results. Out of the 67 sera, 64 reacted with the 23 kDa band and 61 with the one of 17 kDa. These two bands were not detected in sera from patients with other parasitic diseases or in those from healthy volunteers and thus could be considered specific and diagnostic. Conclusions. The sensitivity of the test, using the bands of 17 and 23 kDa, was 95.5 percent for positive reactions to at least one of these two bands, being its specificity 100 percent with a positive predictive value of 100 percent and negative predictive value of 95.71 percent.

Circulating filarial antigen in serum and hydrocele fluid from individuals living in an endemic area for bancroftian filariasis.

This study examined circulating filarial antigen by monoclonal antibody Og4C3-enzyme-linked immunosorbent assay (ELISA) from 114 men with hydrocele, living in an endemic area. Nocturnal blood and hydrocele fluid were collected and examined for microfilaria. ELISA was performed on serum and hydrocele fluid for detection of antigen. Amongst 114 cases, 5(4.4%) showed microfilaria in blood but none in fluid. ELISA was positive in 13(11.40%) serum and 5 (4.4%) fluid samples. All five fluid antigen positive cases were positive for antibodies and showed microfilaria in blood. These findings emphasize the use of circulating filarial antigen detection and alternative usage of hydrocele fluid for diagnosis of filariasis.

Evaluación del efecto protector de 2 inmunógenos de Trchinella spiralis en ratas Long Evans con modificación nutricional e infectado con Trichinella spiralis / Evaluation of the protective effect of 2 inmunogenos of Trchinella spiralis in rats Long Evans with nutritional modification and infected with Trichinella spiralis

La Trichinellosis es una zoonosis endémica, cosmopolita, sus huéspedes son, ratas, cerdo y otros mamíferos entre ellos el hombre, la presencia de Trichinellosis se debe a la ingestión de carne de cerdo insuficientemente cocinada, afecta a países con bajos recursos económicos. Se han caracterizado Inmunógenos, siendo el inmunodominante el de 45 kDa, efectivo contra T. spiralis, desafortunadamente no ha cristalizado en una vacuna. Se han descrito efectos de desnutrición (DN) sobre órganos linfáticos. Los mecanismos de defensa del huésped son alterados con DN proteico-calórico (DPC). Evaluar el efecto protector de 2 inmunógenos de T. spiralis en ratas Long Evans con modificación Nutricional e infectado con T. spiralis. 80 ratas Long Evans de 30 días de edad, divididas en 2 grupos: 40 Nut con 24 de proteína y 40 DN con 12 de proteína de los cuales se subdividieron en 8 sub grupos con tratamiento: a) 10 animales control b)10 animales infectados con T. spiralis, c) 10 animales inmunizados con antígeno soluble total (AST), d) 10 animales inmunizados con inmunógeno de 45 kDa de T. spiralis (esquema de inmunización una aplicación cada semana por 4 ocasiones), retados a la 1era semana de la culminación de inmunización, sacrificadas a la 6 sexta semana post-infección. Parámetros a evaluar: Determinación de la carga parasitaria mediante la Digestión Artificial (D/A), Determinación de las características morfológicas de la célula nodriza por la técnica de compresión de tejidos, detección de la respuesta inmune por WB. Con la técnica de D/A, se obtuvieron en los diferentes tratamientos, de las ratas Nut, DN, Inmunizadas e Infectadas. Mostró diferencia significativa en la cantidad de Ll que se presentaron en 30gr de músculos estriado, los grupos controles de ratas Nut y DN sin infección, ausencia de Ll, y en los grupos de ratas Nut infectadas, se recolectaron 200 µl de Ll, para el grupo de DN infectado se recolecto 400 µl de Ll, en el grupo de Nut inmunizadas con AST.

Influence of the cerebrospinal fluid laboratory parameters in the ELISA test for neurocysticercosis using a total cysticerci antigen

Avaliar se os parâmetros do líquido cefalorraquidiano (LCR) podem influenciar na reatividade da resposta imune específica do LCR na neurocisticercose (NC). Amostras de LCR de 109 pacientes foram analisadas e classificadas em três grupos, de acordo com as manifestações neurológicas e reatividade do teste de Ab-ELISA para NC no LCR. Grupo A, 18 pacientes com enfermidades neurológicas compatíveis com NC e reatividade do teste Ab-ELISA para NC no LCR; grupo B, 50 pacientes com enfermidades neurológicas não compatíveis com NC e reatividade do teste Ab-ELISA para NC no LCR; grupo C, 41 pacientes com enfermidades neurológicas não compatíveis com NC e na ausência de reatividade do teste de Ab-ELISA para NC no LCR. A análise do LCR do grupo A foi compatível com NC. O grupo B apresentou maior freqüência e intensidade da pleocitose, da presença de hemácias no LCR, hiperproteinorraquia, reatividade imune para outros agentes etiológicos em comparação aos grupos A e C (p<0.05). Os dados indicam que o processo inflamatório e os elevados níveis de concentração da proteína no LCR podem influenciar na ocorrência de reações falso positivas de Ab-ELISA para NC. Destacamos a importância da correlação clínico-laboratorial para o diagnóstico de neurocisticercose e o uso de testes laboratoriais confirmatórios.

Antígenos de larvas pulmonares de Ascaris suum reconocidos por anticuerpos producidos en Oryctolagus cuniculus / Ascaris suum lung larvae antigens recognized by antibodies produced in Oryctolagus cuniculus

El presente trabajo tuvo como objetivo determinar mediante la técnica de Western Blot los antígenos de larvas pulmonares de Ascaris suum que son detectados por anticuerpos producidos en Oryctolagus cuniculus inmunizado experimentalmente. Las larvas pulmonares (L3 y L4) fueron obtenidas en 120 ejemplares de Mus musculus cepa BALB/c ratón infectados experimentalmente por vía oral con huevos infectivos de A. suum. Parte de estas larvas fueron cultivadas en el medio Eagle (MEM) para la obtención de antígenos de excreción/secreción y la otra fue sonificada para la obtención de antígenos somáticos, los cuales sirvieron para inmunizar dos ejemplares de O. cuniculus, utilizando Adyuvante Completo e Incompleto de Freund. A las 5 semanas de inmunización se obtuvo sangre de los conejos por punción cardiaca a fin de recuperar el suero, parte del cual fue purificado parcialmente por precipitación salina y diálisis. Mediante la técnica de electroinmuno-transferencia (Western Blot) y usando sueros de los conejos inmunizados se detectaron en los antígenos de excreción/secreción de 20 horas de cultivo reducidos con dithiothreitol, 12 bandas antigénicas de 100, 72.4, 56.2, 42.7, 39.8, 34.6, 31.6, 30.2, 19.5, 16.9, 15.5 y 14.9 KDa, siendo las más reactivas las de 100, 72.4, 16.9, 15.5 y 14.9 KDa. En los antígenos somáticos bajo condiciones de reducción, se detectaron solamente seis bandas de 42.7, 39.8, 34.6, 30.2, 28 y 25.2 KDa de poca reactividad. Estos resultados permiten afirmar que los antígenos de excreción/secreción de A. suum de 20 horas de incubación en el medio MEM inducen la producción de un mayor número de anticuerpos de tipo IgG en conejos inmunizados experimen-talmente.

Excretory/secretory antigens (E/SAg) and somatic antigens (SAg) of Ascaris suum lung larvae that induce the immunoglobulin G antibodies production in Oryctolagus cuniculus experimentally immunized was determined. For this purposes, specimens of Mus musculus BALB/c were inoculated orally with infective eggs of A. suum obtained from pigs naturally parasitized in order to obtain the lung larvae. Part of these larvae was cultured in Minimum Essential Medium (MEM) to obtain E/SAg and another part was sonicated to obtain the SAg too. Both, E/SAg and SAg mixed with complete and incomplete Freund's adjuvant were used for rabbits immunization. Five weeks after the immunization, the rabbits were bled by cardiac puncture obtaining the immunosera by centrifugation, which was purified partially by saline precipitation and dialysis. By using an Western blot technique with purified immunoserum and E/SAg obtained to 20 hours and reduced with dithiothreitol, fourteen antigens bands of 100, 72.4, 56.2, 42.7, 39.8, 34.6, 31.6, 30.2, 19.5, 16.9, 15.5 y 14.9 KD, were detected. The bands of 100, 72.4, 16.9, 15.5 and 14.9 KDa were been the most reactives. Thereby the SAg, also reduced with dithiothreitol, seven bands of 42.7, 39.8, 34.6, 30.2, 28.0 and 25.2 KDa were detected. They were a bit clear. In conclusion, the E/SAg induce the highest production of immunoglobulin G antibodies in rabbits experimentally immunized.

Association of intestinal helminths with decreased liver size and sCD23 concentration during falciparum malaria.

To determine if intestinal helminths and the CD23/nitric oxide pathway had an influence on liver size, we conducted a cross-sectional study on 438 patients with confirmed P. falciparum malaria admitted at the Hospital for Tropical Diseases in Bangkok. For all patients the liver size was measured as number of centimeters below the rib cage, a stool examination was conducted, and CD23 and reactive nitrogen intermediates were measured. The median liver size was smaller in helminth-infected patients than in helminth-free patients (chi2 for trend = 9.1, p = 0.003). Liver size significantly increased with the concentration of sCD23 (p < 0.0001). The median sCD23 concentration (OD) was significantly lower in helminth-infected patients than in helminth-free patients, respectively 0.33 (quartiles 0.24-0.57) and 0.45 (quartiles 0.27-0.59), (p = 0.01). There was a negative correlation between sCD23 concentrations and RNI (Spearman's rho = -0.40, p < 0.0001). All the above results remained significant after controlling for potential confounders. These results are compatible with a CD23/NO-mediated decrease in liver size in helminth-infected patients.

Immunoblot findings of calcareous corpuscles binding proteins in cyst fluid of Taenia solium metacestodes

After collecting calcareous corpuscles from plerocercoid of Spirometra mansoni (sparganum), we evaluated the antigenic values of calcareous corpuscles binding proteins obtained from the cyst fluid of Taenia solium metacestodes. Immunoblot analysis revealed that cysticercosis patient sera strongly recognized 10 and 95 kDa calcareous corpuscles binding proteins. This result demonstrated that calcareous corpuscles are bound with major secretory antigenic proteins, which is possibly involved in the secretory pathways of the 10 and 95 kDa proteins presenting in the cyst fluid of T. solium metacestodes.

Organ-specific antigens of Clonorchis sinensis

This study was carried out to find out specific proteins from different organs of Clonorchis sinensis. Crude extract, organ-specific and excretory-secretory (ES) proteins were analyzed by immunoblot with infected human sera. The bands of 7- and 17-kDa were main component of intestinal fluid and ES protein and commonly found in all organspecific proteins. The 17-kDa protein was observed from ES antigen, intestinal fluid, eggs and sperms, 26- and 28- kDa proteins were from the uterus, vitellaria, and ovary, and 34-, 37-, 43- and 50-kDa proteins were mainly from the testis and sperms. Serum of mice immunized with sperms reacted to the 50-kDa protein by immunoblotting and immunohistochemical staining showed a positive reaction at the seminal receptacle and seminiferous tubule. The present results show that the 7-kDa protein is a common antigen of every part or organ of C. sinensis, but different organs express their specific antigenic protein bands.

Enzymatic N-glycan analysis of 31 kDa molecule in plerocercoid of Spirometra mansoni (sparganum) and its antigenicity after chemical oxidation

A highly specific antigenic protein of 31 kDa from plerocercoid of Spirometra mansoni (sparganum) was obtained by gelatin affinity and Mono Q anion-exchange column chromatography. The purified 31 kDa protein was subjected to N-glycan enzymatic digestion for structural analysis. The relative electrophoretic mobility was analyzed by SDS-PAGE, before and after digestion. On SDS-PAGE after enzymatic digestion, the 31 kDa protein showed a molecular shift of approximately 2 kDa, which indicated the possession of complex N-linked oligosaccharides (N-glycosidase F sensitive) but not of high-mannose oligosaccharides (endo-beta-N-acetylglucosaminidase H, non-sensitive). Chemically periodated 31 kDa protein showed statistically non-significant changes with human sparganosis sera by enzyme linked immunosorbent assay (ELISA). Therefore, the dominant epitopes of the 31 kDa molecule in human sparganosis were found to be mainly polypeptide, while N-glycans of the antigenic molecule in sparganum was minimal in anti-carbohydrate antibody production.

An antigen detection assay for diagnosing filariasis.

In this study we examined the diagnostic potential of monoclonal antibodies (MAb) reactive to antigens of adult Brugia malayi, their microfilariae and antigen of Dirofilaria immitis. The MAb of clone 17E10, which were of IgM isotype, reacted to the inner cuticles and internal content of both male and female worms and also to the sheath and internal content of microfilariae in utero. However, these MAb did not react to the sheath of blood circulating microfilariae. The MAb 17E10 produced a smear pattern between 37 to > 200 kDa in the Western blot analysis against a SDS-PAGE separated extract of B. malayi. The epitopes were non-protein in nature as indicated by their resistance to proteinase-K treatment. The MAb 17E10 were applied in a sandwich ELISA to detect filarial antigen in the buffy coat and plasma of patients. We tested patients with different clinical manifestations of brugian filariasis, i.e. microfilaremia (M), lymphangitis (L) and elephantiasis (E), as well as non-symptomatic inhabitants of a filariasis endemic area (NE), and compared them to samples from non-symptomatic inhabitants of disease non-endemic areas (NNE). It was found that 22 of 31 (70.9%) of M, 7 of 13 (53.8%) of L, 2 of 14 (14.2%) of E, 10 of 100 (10.0%) of NE and none (0%) of the NNE were positive for antigenaemia. The assay was also positive in 14 of 15 (93.3%) blood samples from B. malayi microfilaremic cats and in 7 of 7 (100%) blood samples of Dirofilaria immitis microfilaremic dogs. The so-developed test has a high potential for routine diagnosis of active filariasis, for epidemiological studies in both humans and reservoir animals and for monitoring treatment efficacy.

Comparative assessment of an Og4C3 ELISA and an ICT filariasis test: a study of Myanmar migrants in Thailand.

Detection of circulating filarial antigen has now emerged as an alternative method for the diagnosis of bancroftian filariasis. We compared two antigen detection assays, an Og4C3 ELISA and an ICT (immunochromatography) Filariasis test, for the diagnosis of Wuchereria bancrofti infections in migrant Myanmar workers in Tak province, Western Thailand. A total of 337 Myanmars participated in this study. The microfilarial rate was 3.3%. The Og4C3 ELISA could detect 19.1% of bancroftian filariasis while the ICT test detected 12.7%. Both antigen assays could detect all microfilaremics. The Og4C3 ELISA detected 14.8% of amicrofilaremics while the ICT test identified 8.1%. Those who were positive for the ICT test were also positive by the Og4C3 ELISA. Those Og4C3 positive cases, that were ICT negative (ICT-ve/Og4C3+ve) had statistically significant (p < 0.05, unpaired t-test) lower Og4C3 antigen levels (409.5 units, range 117-2,389) than those that were ICT positive (ICT+ve/Og4C3+ve) (5,252.0 units, range 130-28,062). Our results emphasize the problem of bancroftian filariasis in Myanmar migrants working in Thailand. Close monitoring and control of this disease in Myanmar migrants are of public health importance. Antigen detection systems are promising tools for the surveillance of bancroftian filariasis.

Prevalence of bancroftian filariasis on the Thai-Myanmar border.

To achieve the goal of eliminating lymphatic filariasis by the year 2020, close monitoring systems and effective control strategies need to be implemented and the real disease burden needs to be assessed. Bancroftian filariasis is endemic at the Thai-Myanmar border. However, there are only limited data on the prevalence of this disease in Thailand available. We employed microscopic examination, together with ELISA kits to detect W. bancrofti-specific Og4C3 circulating antigen and specific anti-filarial IgG4 antibodies to determine the burden of bancroftian filariasis in an endemic area at the Thai-Myanmar border in Umphang District, Tak province, Thailand. A total of 433 Thai-Karen blood samples were analyzed. The microfilarial rate determined by microscope was 6% and the W. bancrofti-specific Og4C3 antigenemia rate was 22%, while the specific anti-filarial IgG4 antibody rate was 54%. There were statistically significant higher levels of W. bancrofti-specific Og4C3 antigen in the microfilaremic-antigenemic group than in the amicrofilaremic-antigenemic group (unpaired Student's t-test; p < 0.001), similar to the specific anti-filarial IgG4 antibody results (unpaired Student's t-test; p < 0.001). A statistically significant correlation of moderate degree between the presence of W. bancrofti-specific Og4C3 antigen and of specific anti-filarial IgG4 antibody was found in the amicrofilaremic group (r = 0.474, p < 0.001), but not in the microfilaremic group (r = 0.291, p > 0.05). Our study revealed a very high prevalence of bancroftian filariasis in this endemic area and thus emphasized the importance of using highly sensitive and specific diagnostic tools to evaluate the true prevalence of the disease.

Localization of antigenic molecules of adult Fasciola gigantica using monoclonal antibodies against the parasite tegumental antigen.

In this study, monoclonal antibodies were developed from the partially purified surface tegumental antigens of F. gigantica. Nine MoAbs: 2G11, 1G2, 1B12, 2G2, 2G5, 3C6, 3G2, 3G3 and 3F6 were used for anatomical localization of adult F. gigantica. The reaction was demonstrated by Avidin-Biotin method. The results revealed that among the sections stained with non-immune sera and control group, there were no reaction products on either the tegument or the cecal epithelium. The only brownish areas were the vitelline glands. In the sections stained with immune sera, brownish reaction products appeared on the surface membrane, the spine membrane, the cecal lumen and its epithelial cells. The experiment sections of nine monoclonal antibodies revealed that the reaction occurred mainly on the tegument of the adult worm which covered its surface and spine.

Teniosis y detección de anticuerpos anticisticerco en personas de una comunidad rural del estado de Guerrero / Taeniosis and detection of antibodies against cysticerci among inhabitants of a rural community in Guerrero State, Mexico

OBJETIVO: Determinar la frecuencia de portadores de Taenia sp. y su relación con el diagnóstico de cisticercos en humanos en una comunidad rural del estado de Guerrero, México. MATERIAL Y MÉTODOS: Para detectar portadores de Taenia sp. se analizaron 403 muestras de heces de personas, por medio de ELISA para coproantígenos de Taenia sp., así como 92 muestras de suero para detectar anticuerpos anticisticerco mediante inmunoelectrotransferencia. El diseño del estudio fue transversal y se llevó a cabo durante 1998. Se hizo estadística descriptiva y se estimó razón de momios. RESULTADOS: De 403 muestras de heces evaluadas, cinco resultaron positivas (1.2 por ciento). Sólo en dos de las cinco personas positivas se obtuvo el cestodo adulto. En 3 (3.26 por ciento) de los 92 sueros se encontraron anticuerpos anticisticerco. Del total de sueros, 17 fueron de las personas con diagnóstico positivo a teniosis por coproantígenos o que cohabitaban con ellos (primer grupo), los restantes 75 provenían de personas en quienes no se detectaron casos en las viviendas (segundo grupo). En el primer grupo se detectaron 2 (11.8 por ciento) sueros positivos, mientras que en el segundo sólo 1 (1.3 por ciento) (RM= 9.87, I.C 0.64-295.56, p= 0.086). CONCLUSIONES: La dificultad para obtener el parásito adulto en las personas positivas a coproantígenos puede deberse a características propias de éste que dificultan su expulsión, a que la permanencia del cestodo en su huésped es menor a la esperada o a que el tratamiento fue insuficiente para obtener el parásito, o bien, a problemas de especificidad de la prueba. Es necesario realizar estudios tendientes a evaluar estas posibilidades, lo cual permitiría conocer mejor la dinámica de transmisión de esta parasitosis, con el fin de establecer medidas de prevención y control, además de poder comparar con mayor veracidad la eficacia de las pruebas diagnósticas en condiciones de campo

Excretory-secretory antigen is better than crude antigen for the serodiagnosis of clonorchiasis by ELISA

Although stool examination is the standard diagnostic method of clonorchiasis, serodiagnosis by ELISA using crude antigen is now widely used because of its convenience. However, ELISA diagnosis still suffers from cross-reactions, and therefore there is a need to improve the present conventional ELISA. The present study was undertaken to evaluate the diagnostic value of ELISA using excretory-secretory antigen (ESA) instead of crude antigen (CA) of Clonorchis sinensis. The diagnostic sensitivity of ELISA using excretory-secretory antigen was 92.5%, which was higher than that of ELISA using crude Clonorchis sinensis antigen (88.2%). In addition, the specificity of excretory-secretory antigen was found 93.1% while that of crude antigen was 87.8%. In summary, Clonorchis sinensis ESA was found to be a better serodiagnostic antigen than CA for ELISA.