Avidity as a criterion for diagnosis of human strongyloidiasis increases specificity of IgG ELISA.

This study evaluates the inclusion of the IgG avidity index in ELISA to detect anti-Strongyloides stercoralis IgG. The ELISA index revealed 70% of specificity. With the inclusion of screening AI, specificity increased to 80%. IgG avidity complemented traditional IgG ELISA by eliminating some of the suspected or false positive cases.

Specific IgG and IgA to larvae, parthenogenetic females, and eggs of Strongyloides venezuelensis in the immunodiagnosis of human strongyloidiasis.

The aim of this study was to detect levels of IgG and IgA by enzyme-linked immunosorbent assay (ELISA) using alkaline extracts of larvae, adult female worms, and eggs of Strongyloides venezuelensis as antigen. One hundred twenty serum samples divided into 3 groups were analysed: group I (40 strongyloidiasis patients), group II (40 patients with other parasitic infections), and group III (40 healthy subjects). Statistical variations were analyzed using analysis of variance. There was a significant statistical difference (P < 0.001) in the detection of antibodies in group I between larvae and female antigens and between larvae and egg antigens, with higher positivity using larvae antigen. The larvae antigen showed the highest values for sensitivity, specificity, and diagnostic efficiency in ELISA. This study is the first that examines the use of adult female worm and egg antigens to detect antibodies for human strongyloidiasis diagnosis compared with the larval extract. By comparing all 3 extracts, larval antigens demonstrated better diagnostic parameters.

Strongyloides venezuelensis: the antigenic identity of eight strains for the immunodiagnosis of human strongyloidiasis.

The antigens of eight strains of Strongyloides venezuelensis were identified by means of the indirect immunofluorescence antibody (IFAT), enzyme-linked immunosorbent assay (ELISA) and immunoblot (IB) tests. Infective larvae (L3) from these strains were obtained from Rattus norvegicus feces cultures. For IFAT, sections of L3 were used while the ELISA and IB, tests were conducted with alkaline extract. Ninety serum samples were tested: 30 from patients with S. stercoralis, 30 from patients with other parasitic diseases, and 30 from healthy subjects (free of parasites). Average sensitivity and specificity among all eight strains, both for IFAT and ELISA, were, respectively, 93% and 100%. In the IB, anti-S. stercoralis IgG recognized a single antigenic fraction with 45 kDa. Serum samples from patients with S. stercoralis revealed antigens from different strains of S. venezuelensis, indicating antigenic identity for possible use in the synthesis of recombinant antigen that could be useful in immunodiagnosis and vaccine against this parasite.

Detection of Cryptosporidium - specific coproantigen in human immunodeficiency virus/acquired immunodeficiency syndrome patients by using a commercially available immunoenzymatic assay

The aim of this study was to verify the occurrence of Cryptosporidium infection in 52 human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients (group 1) and 38 clinically healthy individuals (group 2) by using enzyme immunoassay (EIA). All fecal samples collected were submitted to the Baermann, Lutz, and Ritchie methods, the Safranin/Methylene Blue, and Weber's chromotrope modified Trichrome staining techniques, and EIA. In group 1, parasitological staining techniques and EIA were both positive for Cryptosporidium sp. infection in 3/52 (5.8 percent) samples and both negative in 45/52 (86.5 percent) samples, while 4/52 (7.7 percent) samples were positive in EIA and negative in parasitological staining techniques. Concerning group 2, all samples were negative by EIA and microscopy for Cryptosporidium infection. In conclusion, EIA may be an alternative method for detecting Cryptosporidium-specific coproantigen in HIV/AIDS patients.

Strongyloides venezuelensis alkaline extract for the diagnosis of human strongyloidiasis by enzyme-linked immunosorbent assay

The present study was conducted to detected IgG antibodies using Strongyloides venezuelensis alkaline extract for the diagnosis of human strongyloidiasis by the enzyme-linked immunosorbent assay (ELISA). Sera from 90 subjects were analyzed (30 with strongyloidiasis, 30 with other parasites and 30 healthy individuals). Results were expressed in antibody titers, which were considered as positive when titer was > 80. Sensibility and specificity of the assay were 100 percent and 96.7 percent, respectively. It can be concluded that the heterologous alkaline extract could be employed in ELISA as a diagnostic aid in human strongyloidiasis, due to its advantages as easiness of obtaining, practicability in preparing, and high indexes of sensitivity and specificity

Detection of Cryptosporidium--specific coproantigen in human immunodeficiency virus/acquired immunodeficiency syndrome patients by using a commercially available immunoenzymatic assay.

The aim of this study was to verify the occurrence of Cryptosporidium infection in 52 human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients (group 1) and 38 clinically healthy individuals (group 2) by using enzyme immunoassay (EIA). All fecal samples collected were submitted to the Baermann, Lutz and Ritchie methods, the Safranin/Methylene Blue, and Weber's chromotrope modified Trichrome staining techniques, and EIA. In group 1, parasitological staining techniques and EIA were both positive for Cryptosporidium sp. infection in 3/52 (5.8%) samples and both negative in 45/52 (86.5%) samples, while 4/52 (7.7%) samples were positive in EIA and negative in parasitological staining techniques. Concerning group 2, all samples were negative by EIA and microscopy for Cryptosporidium infection. In conclusion, EIA may be an alternative method for detecting Cryptosporidium-specific coproantigen in HIV/AIDS patients.

Parasitological and immunological diagnoses of strongyloidiasis in immunocompromised and non-immunocompromised children at Uberlândia, state of Minas Gerais, Brazil

Parasitological and immunological diagnoses were part of a study conducted among 151 children, 83 immunocompromised (IC) and 68 non-immunocompromised (non-IC) aged from zero to 12, seen at the University Hospital, Universidade Federal de Uberlândia, State of Minas Gerais, Brazil, from February, 1996, to June, 1998. Three fecal samples from each child were analyzed for the parasitological diagnosis by Baermann-Moraes and Lutz methods. The immunological diagnosis to detect IgG and IgM antibodies was carried out by the indirect immunofluorescence antibody test (IFAT) with cryo-microtome sections of Strongyloides stercoralis and Strongyloides ratti larvae as antigens and by the ELISA test with an alkaline extract of S. ratti as the antigens. Of the 151 children 5 (3.31 percent) were infected with larvae of S. stercoralis (2 cases IC, 2.41 percent, and 3 cases non-IC, 4.41 percent). The IFAT-IgG detected 7 (8.43 percent) serum samples positive among IC, and 2 (2.94 percent) cases among non-IC. The ELISA-IgG test detected 10 (12.05 percent) serum samples positive among IC, and 1 (1.47 percent) case among non-IC. The IFAT-IgM detected 6 (7.22 percent) positive cases among IC, and 3 (4.41 percent) cases among non-IC. ELISA-IgM test detected 10 (12.05 percent) positive cases among IC, and 3 (4.41 percent) cases among non-IC. It was concluded that the immunological tests can help in the diagnosis of strongyloidiasis in immunocompromised children

Leishmaniose tegumentar, visceral e doença de Chagas caninas em municípios do Triângulo Mineiro e Alto Paranaíba, Minas Gerais, Brasil / Canine cutaneous and visceral leishmaniasis and chagas'disease from counties in the Triângulo Mineiro and Alto Paranaíba regions, Minas Gerais State, Brazil

Inquérito envolvendo leishmaniose e doença de Chagas, por meio da reaçäo de imunofluorescência indireta, foi realizado com soros de 331 cäes de Uberlândia e Coromandel, municípios do Estado de Minas Gerais, Brasil. Para o inquérito, utiliza, como antígenos, Leishmania amazonensis e Trypanosoma cruzi. No que tange a Uberlândia, examinaram-se 230 soros, sendo 200 da área urbana com 4,5 por cento de positividade, e 30 da área rural, dos quais, 6,6 por cento positivos para a RIFI com antígeno L. amazonensis. No que se refere a Coromandel, a mesma reaçäo realizada em 89 soros, com o mesmo antígeno, L. amazonensis, foi positiva em 5,6 por cento dos cäes. Além dos 230 soros de Uberlândia, mais 12, advindos de cäes atendidos no Hospital Veterinário da Universidade Federal de Uberlândia, com suspeita clínica de leishmaniose, foram incluídos; destes, os soros de dois reagiram à reaçäo de imunofluorescência indireta, sendo um positivo frente ao antígeno L. amazonensis, e o outro, frente ao antígeno T. cruzi. Tais resultados sugerem a urbanizaçäo da leishmaniose e da doença de Chagas em cäes.

Leishmaniose Tegumentar Americana no Triangulo Mineiro e Alto Paranaiba, Minas Gerais, Brasil: aspectos clinico-laboratoriais e epidemiologicos de uma microepidemia / Cutaneous leishmaniasis in the Triangulo Mineiro and Alto Paranaiba, Minas Gerais, Brazil: aspects of a clinical-laboratorial and epidemiological of a microepidemy

No periodo de julho a novembro de 1987 foram diagnosticados 25 casos de leishmaniose tegumentar americana(LTA) procedentes de municipios da regiao do Triangulo Mineiro e Alto Paranaiba, Minas Gerais. Todos eram pessoas que frequentaram as margens dos rios Araguari(22) e Paranaiba(3) para atividades de trabalho, esportivas e de lazer. Houve predominancia de pacientes masculinos(88 por cento) e acima de 20 anos de idade(84 por cento). As lesoes foram exclusivamente cutaneas, mais frequentemente unicas(68 por cento), e tiveram localizacao preferencial nos membros inferiores (47,7 por cento). O intervalo entre o aparecimento das lesoes e o diagnostico variou entre 7 e 180 dias. Dentre 23 biopsias, confirmou-se a presenca de amastigotas em 96 por cento dos casos nos "imprints" e em 95 por cento nos exames histopatologicos. O exame histopatologico realizado em 22 casos revelou infiltrado info-histocitario difuso em 54,6 por cento, granulomas desorganizados em 40,0 por cento e granulomas tuberculoides em 4,5 por cento. A inflamacao, em alguns casos, esteve associada a (83,3 por cento), IgM (72,2 por cento) e IgA (16,7 por cento). O estudos morfometricos e ultraestruturais de amastigota, as avaliacoes do comportamento biologico "in vivo" e "in vitro" e a caracterizacao bioquimica atraves do metodo de hibridizacao citologica "in situ", indicaram a especie Leishmania (Viannia) braziliensis como responsavel pelo primeiro surto de LTA da regiao do Triangulo Mineiro e Alto Paranaiba.