Chagas Immunochromatographic Rapid Test in the Serological Diagnosis of Trypanosoma cruzi Infection in Wild and Domestic Canids.

Canis lupus familiaris (domestic dog) represents a reliable sentinel for the occurrence of a well-established transmission cycle of Trypanosoma cruzi among wild mammals in the surroundings and, consequently, where the risk of human infection exists. Serological diagnosis is the chosen method to identify T. cruzi infection in dogs that, in Brazil, rarely present positive parasitological tests. The use of recombinant chimeric parasitic antigens results in a sensitive and specific serological diagnostic test in contrast to the use of crude T. cruzi antigens. Our objective was to evaluate the Chagas/Bio-Manguinhos Lateral Flow Immunochromatographic Rapid Test (Chagas-LFRT) for the diagnosis of T. cruzi infection in domestic dogs and the potential of application of this diagnostic platform to wild canid species. Two recombinant proteins (IBMP-8.1 and IBMP-8.4) that displayed the best performance in the enzyme immunoassay (ELISA) in previous studies were tested in a platform with two diagnostic bands. A panel of 281 dog serum samples was evaluated: 133 positive for T. cruzi by serological diagnosis, including 20 samples with positive blood cultures belonging to different discrete typing units (DTUs); 129 negative samples; and 19 samples from dogs infected by other trypanosomatids: Leishmania infantum, Trypanosoma rangeli, Trypanosoma caninum and Crithidia mellificae, in addition to samples infected by Anaplasma platys, Dirofilaria immitis and Erlichia sp. that were employed to evaluate eventual cross-reactions. We also evaluated the Chagas-LFRT to detect T. cruzi infection in 9 serum samples from six wild canid species. We observed that the intensity pattern of the bands was directly proportional to the serological titer observed in IFAT. The sensitivity was 94%, the specificity was 91% according to the ROC curve, and the defined cutoff was an optical density of 4.8. The agreement obtained was considered substantial by the kappa analysis (84%). From T. cruzi positive hemoculture samples, 88.9% were positive by Chagas-LFRT. The test was efficient in recognizing infections by five of the six T. cruzi DTUs. Cross-reactions were not observed in infections by L. infantum, T. rangeli, T. caninum and D. immitis; however, they were observed in sera of dogs infected by Crithidia mellificae, Anaplasma sp. and Erlichia sp. A strong reaction was observed when serum samples from wild canids were submitted to the Protein A affinity test, confirming its applicability for these species. This test will allow rapid preventive actions in areas with high risk to the emergence of Chagas disease in a safer, reliable, low-cost and immediate manner, without the need for more complex laboratory tests.

Development of a New Lateral Flow Assay Based on IBMP-8.1 and IBMP-8.4 Chimeric Antigens to Diagnose Chagas Disease.

Despite several available methodologies for Chagas disease (CD) serological screening, the main limitation of chronic CD diagnosis is the lack of effective tools for large-scale screening and point-of-care diagnosis to be used in different CD epidemiological scenarios. Taking into account that developing such a diagnostic tool will significantly improve the ability to identify CD carriers, we aimed at performing a proof-of-concept study (phase I study) to assess the use of these proteins in a point-of-care platform using serum samples from different geographical settings of Brazil and distinct clinical presentations. The diagnostic accuracy study was conducted on a panel of two WHO International Standards (IS) and 14 sera from T. cruzi-positive and 16 from T. cruzi-negative individuals. The results obtained with the test strips were converted to digital images, allowing quantitative comparison expressed as a relative band intensity ratio (RBI). The diagnostic potential and performance were also determined. Regardless of the geographical origin or clinical presentation, all sera with T. cruzi antibodies returned positive both for IBMP-8.1 and IBMP-8.4 chimeric antigens. The area under the ROC curve (AUC) values was 100% for both antigens, demonstrating an outstanding overall diagnostic accuracy (100%). Based on the data, we believe that the lateral flow assays based on these antigens are promising methodologies for screening CD.

Identificação e análise de rotulagem das marcas de mel comercializadas na cidade do Rio de Janeiro / Identification and analysis of honey labeling commercialized in Rio de Janeiro city

Com vistas a identificar as marcas dos méis comercializados e suas características de rotulagem no comércio varejista dacidade do Rio de Janeiro, foram realizadas 48 visitas em diferentes estabelecimentos. Identificaram-se 37 marcas de méisregularmente registradas e a análise da rotulagem permitiu observar inadequações (56,8%) relativas à falta de informaçõesobrigatórias tais como: informação nutricional (8,1%), data da embalagem (13,5%), prazo de validade (2,7%), lote (27,0%) emodo de conservação (5,4%). Todas as marcas encontradas apresentaram as informações obrigatórias: conteúdo líquido,identificação da marca e da firma produtora, assim como a identificação do registro no órgão competente. Os dados obtidosneste estudo, ainda que não alarmantes, sugerem o estabelecimento de programas que permitam a adoção de açõescoercitivas típicas de fiscalização de alimentos com vistas a garantir alimentos saudáveis e de menor risco na mesa dosconsumidores, conforme prevê a legislação sanitária

The objective was to identify the marks of the commercialized honeys and labeling characteristics of retailing commerce in Riode Janeiro city. It was performance 48 visits in different establishments. It was identified 37 marks of regularly registered honeysand the labeling analysis allowed observing inadequacies (56.8%) relative to the lack of obligator information such as: nutritionalinformation (8.1%), packing date (13.5%), shelf-live period (2.7%), lot (27.0%) and way of conservation (5.4%). All the joinedmarks had presented the obligator information: liquid content, identification of the mark and the producing firm, as well as theidentification of the register in the competent agency. The data gotten in this study, despite not alarming, suggest the establishmentof programs that allow the adoption of typical coercitive actions of fiscalization of foods with sights to guarantee healthful foodsand lesser risk to the consumers, as foresee the legislation