Desafios da implantação de testes rápidos para o diagnóstico da leishmaniose visceral em serviços de saúde de município endêmico para a doença

O objetivo deste estudo foi descrever e discutir fatores facilitadores e desafios enfrentados durante o processo de incorporação de um teste rápido para o diagnóstico da leishmaniose visceral (LV) humana em serviços de saúde de município endêmico para a doença no Brasil. Este estudo foi dividido em quatro eixos de análise, seguindo as etapas de execução do estudo: 1) Descrição do sistema de saúde local e da tecnologia a ser implantada; 2) Contexto e atividades preparatórias; 3) Resultados da avaliação da implantação, da aceitação e do desempenho do algoritmo diagnóstico; 4) Conclusões, considerações e recomendações. O estudo foi conduzido em Ribeirão das Neves, no estado de Minas Gerais; o teste rápido implantado, o IT LEISH®, executado a partir de sangue capilar. Impasses e desafios estiveram relacionados à recusa de profissionais de saúde em realizar o IT LEISH® durante as capacitações, como dificuldade no processo de compra do teste rápido e atraso na entrega, dificuldades para coleta do sangue capilar relatada por pacientes e profissionais de saúde e falta de clareza entre os profissionais sobre suas atribuições e responsabilidades nas unidades de saúde, além de evasão de pacientes para cidade de maior porte. Este estudo apontou para a viabilidade da implantação de um teste rápido que descentralizasse e favorecesse o acesso ao diagnóstico laboratorial da LV. No entanto, no período do estudo, a maioria dos casos de LV residentes em Ribeirão das Neves foi diagnosticada em outro município, Belo Horizonte. Tal constatação aponta para desarticulação interna envolvendo os serviços de saúde do município, seja no acolhimento e na identificação dos suspeitos de LV, seja na efetiva utilização dos recursos disponíveis. Mesmo assim, identificamos dois aspectos determinantes para a realização da implantação: o engajamento de profissionais lotados em setores estratégicos da gestão municipal e a existência de financiamento. Estes resultados demonstram a complexidade do processo de implantação de uma nova tecnologia e apontam para a necessidade de trabalho integrado. Do contrário, a disponibilidade de testes rápidos para LV não será suficiente para garantir acesso e redução da letalidade pela doença

Panoramic snapshot of serum soluble mediator interplay in pregnant women with convalescent COVID-19: an exploratory study

IntroductionSARS-CoV-2 infection during pregnancy can induce changes in the maternal immune response, with effects on pregnancy outcome and offspring. This is a cross-sectional observational study designed to characterize the immunological status of pregnant women with convalescent COVID-19 at distinct pregnancy trimesters. The study focused on providing a clear snapshot of the interplay among serum soluble mediators.MethodsA sample of 141 pregnant women from all prenatal periods (1st, 2nd and 3rd trimesters) comprised patients with convalescent SARS-CoV-2 infection at 3-20 weeks after symptoms onset (COVID, n=89) and a control group of pre-pandemic non-infected pregnant women (HC, n=52). Chemokine, pro-inflammatory/regulatory cytokine and growth factor levels were quantified by a high-throughput microbeads array.ResultsIn the HC group, most serum soluble mediators progressively decreased towards the 2nd and 3rd trimesters of pregnancy, while higher chemokine, cytokine and growth factor levels were observed in the COVID patient group. Serum soluble mediator signatures and heatmap analysis pointed out that the major increase observed in the COVID group related to pro-inflammatory cytokines (IL-6, TNF-α, IL-12, IFN-γ and IL-17). A larger set of biomarkers displayed an increased COVID/HC ratio towards the 2nd (3x increase) and the 3rd (3x to 15x increase) trimesters. Integrative network analysis demonstrated that HC pregnancy evolves with decreasing connectivity between pairs of serum soluble mediators towards the 3rd trimester. Although the COVID group exhibited a similar profile, the number of connections was remarkably lower throughout the pregnancy. Meanwhile, IL-1Ra, IL-10 and GM-CSF presented a preserved number of correlations (≥5 strong correlations in HC and COVID), IL-17, FGF-basic and VEGF lost connectivity throughout the pregnancy. IL-6 and CXCL8 were included in a set of acquired attributes, named COVID-selective (≥5 strong correlations in COVID and <5 in HC) observed at the 3rd pregnancy trimester.Discussion and conclusionFrom an overall perspective, a pronounced increase in serum levels of soluble mediators with decreased network interplay between them demonstrated an imbalanced immune response in convalescent COVID-19 infection during pregnancy that may contribute to the management of, or indeed recovery from, late complications in the post-symptomatic phase of the SARS-CoV-2 infection in pregnant women

Use of the Kala-Azar Detect® and IT-LEISH® rapid tests for the diagnosis of visceral leishmaniasis in Brazil

The performances of two rapid tests and a standard serological test for the diagnosis of visceral leishmaniasis (VL) were compared using sera from 193 patients with VL and 85 controls. The Kala-Azar Detect®, IT-LEISH® and IFI-LH® assays showed sensitivities of 88.1%, 93.3% and 88.6%, respectively, and specificities of 90.6%, 96.5% and 80%, respectively. The sensitivity values were similar for both rapid tests, but the specificity and positive predictive values of IT-LEISH® were higher than the corresponding values for IFI-LH®. Both rapid tests showed satisfactory performances and can be used in primary health care settings; however, IT-LEISH® permits the use of whole blood, making this assay more suitable for bedside diagnosis

Acceptance and potential barriers to effective use of diagnostic tests for visceral leishmaniasis in an urban area in Brazil

Abstract: INTRODUCTION: Acceptance of the IT LEISH(r) and direct agglutination test- made in the Laboratório de Pesquisas Clínicas (DAT-LPC) by healthcare professionals and patients suspected of visceral leishmaniasis (VL) in Ribeirão das Neves was evaluated. METHODS: Ninety-two patients and 47 professionals completed three questionnaires. RESULTS: Eighty-eight (96%) patients considered fingertip blood collection a positive test feature, and 86% (37) and 91% of professionals considered the IT LEISH(r) easy to perform and interpret, respectively. All professionals classified the DAT-LPC as simple and easy. CONCLUSIONS: Patients and healthcare professionals in Ribeirão das Neves demonstrated a high degree of acceptance of the IT LEISH(r) and DAT-LPC

Mannosyltransferase (GPI-14) overexpression protects promastigote and amastigote forms of Leishmania braziliensis against trivalent antimony

Abstract Background Glycosylphosphatidylinositol is a surface molecule important for host-parasite interactions. Mannosyltransferase (GPI-14) is an essential enzyme for adding mannose on the glycosylphosphatidyl group. This study attempted to overexpress the GPI-14 gene in Leishmania braziliensis to investigate its role in the antimony-resistance phenotype of this parasite. Results GPI-14 mRNA levels determined by quantitative real-time PCR (qRT-PCR) showed an increased expression in clones transfected with GPI-14 compared to its respective wild-type line. In order to investigate the expression profile of the surface carbohydrates of these clones, the intensity of the fluorescence emitted by the parasites after concanavalin-A (a lectin that binds to the terminal regions of α-D-mannosyl and α-D-glucosyl residues) treatment was analyzed. The results showed that the clones transfected with GPI-14 express 2.8-fold more mannose and glucose residues than those of the wild-type parental line, indicating effective GPI-14 overexpression. Antimony susceptibility tests using promastigotes showed that clones overexpressing the GPI-14 enzyme are 2.4- and 10.5-fold more resistant to potassium antimonyl tartrate (SbIII) than the parental non-transfected line. Infection analysis using THP-1 macrophages showed that amastigotes from both GPI-14 overexpressing clones were 3-fold more resistant to SbIII than the wild-type line. Conclusions Our results suggest the involvement of the GPI-14 enzyme in the SbIII-resistance phenotype of L. braziliensis