Accuracy of the Dual Path Platform (DPP) rapid test for the diagnosis of leptospirosis: A multi-center study in six Brazilian states.

Leptospirosis is a zoonotic disease with significant global impact and a challenging diagnosis. The utilization of adequately validated rapid tests is relevant for the opportune identification of the disease and for reduction in fatality rates. The present study analyzes the accuracy and reliability of the Dual Path Platform (DPP) assay -produced in Brazil by the Oswaldo Cruz Foundation (Fiocruz)- for diagnosing leptospirosis. Firstly, a serological panel was constructed in the Brazilian Reference Laboratory for Leptospirosis using samples routinely handled by reference laboratories of six Brazilian states. It consisted of 150 positive (according to MAT and IgM-ELISA) and 250 negative samples for leptospirosis. Subsequently, the panel samples were distributed to the reference laboratories for the performance of DPP assays in triplicate. Different measures were used in the assessment of diagnostic quality. Predictive values were estimated for different pre-test probability settings. Sensitivities varied between 67.33 % and 74.00 % and specificities between 93.20 % and 98.40 % in the states, and there were adequate agreements between them. Accuracies were lower for the samples of patients with less than 7 days of symptoms. In contexts of prevalence values up to around 25 %, positive and negative predictive values were around 90 %. However, in situations of high pre-test probabilities, NPVs were low. This study improves understanding of the use of DPP in diagnosing leptospirosis, particularly its application in healthcare settings. As long as the time of symptoms onset and clinical and epidemiological contexts are adequately considered for the interpretation of results, DPP is a valid option to be used in the leptospirosis diagnostic routine.

Retrospect, advances and challenges in Chagas disease diagnosis: a comprehensive review.

Chagas disease, caused by Trypanosoma cruzi, affects millions worldwide. The 2030 WHO roadmap aims to eliminate it as a public health concern, emphasising the need for timely diagnosis to enhance treatment access. Current diagnostic algorithms, which rely on multiple tests, have prolonged turnaround times. This proves particularly problematic in resource-limited settings. Addressing this issue necessitates the validation and adoption of innovative tools. We explore recent developments in Chagas disease diagnosis, reviewing historical context and advancements. Despite progress, challenges persist. This article contributes to the understanding of current and future directions in this neglected healthcare area. Parasitological methods are simple but exhibit low sensitivity and require supplementary tests. Molecular methods, with automation potential, allow quantification and higher throughput. Serological tools show good performance but struggle with parasite antigenic diversity. Prioritising point-of-care tests is crucial for widespread accessibility and could offer a strategy to control disease impact. Ultimately, balancing achievements and ongoing obstacles is essential for comprehensive progress.

Asymptomatic Malaria Reservoirs in Honduras: A Challenge for Elimination.

BACKGROUND: Efforts on a global scale for combating malaria have achieved substantial progress over the past twenty years. Two Central American nations have accomplished their goal of eliminating malaria: El Salvador and Belize. Honduras has decreased the incidence of malaria and now reports fewer than 4000 malaria cases annually, aspiring to reach elimination by 2030. To accomplish this goal, it is essential to assess the existing strategies employed for malaria control and to address the task of incorporating novel intervention strategies to identify asymptomatic reservoirs. METHODS: A survey for detecting asymptomatic cases was carried out in the community of Kaukira, in Gracias a Dios, Honduras, focusing on malaria transmission during 2023. Asymptomatic community members were recruited as participants, malaria screening was performed through a rapid diagnostic test in situ, and a blood sample was collected on filter paper. Highly sensitive molecular assays based on photo-induced electron transfer PCR (PET-PCR) were performed to detect the two species of Plasmodium circulating in Honduras: Plasmodium vivax and Plasmodium falciparum. In addition, the identification of the parasite species was verified by amplifying three genetic markers (Pvmsp3α, Pvmsp3ß, and Pfmsp1). RESULTS: A total of 138 participants were recruited, mostly adult women. All individuals tested negative on the rapid diagnostic test. Positive results for malaria were detected by PET-PCR in 17 samples (12.3%). Most samples (12 out of 17) were amplified with a Ct value between 37 and 42, indicating very low parasitemias. Out of the 17 samples, 16 of them also showed amplification in the species assays. There were nine cases of P. falciparum infections and seven cases of P. vivax infections that were further confirmed by nested PCR (nPCR) of Pvmsp3 and Pfmsp1. Parasitemias ranged from 100 p/µL to less than 0.25 p/µL. One sample showed mixed infection. CONCLUSIONS: The existence of asymptomatic malaria reservoirs in Honduras can contribute to disease transmission and pose a challenge that may hinder elimination efforts, requiring public health authorities to modify surveillance strategies to identify the disease and treat this population accordingly.

High Frequency of Deletions in the pfhrp2 and pfhrp3 Genes of Plasmodium falciparum in the Middle Rio Negro Region of the Brazilian Amazon.

Several countries are reporting natural populations of P. falciparum with deletions in the pfhrp2/3 genes that can lead to false-negative results in rapid diagnostic tests. To investigate the prevalence of deletion in the pfhrp2/3 genes in the Rio Negro basin in the Brazilian Amazon and identify whether there is clinical differentiation between individuals infected by these parasites, clinical samples collected from 2003 to 2016 were analyzed from symptomatic and asymptomatic P. falciparum-infected individuals. The molecular deletion of pfhrp2 and pfhrp3 genes was evaluated using the protocols recommended by the WHO. From 82 samples used, 28 (34.2%) had a single deletion in pfhrp2, 19 (23.2%) had a single deletion in pfhrp3, 15 (18.3%) had a double deletion (pfhrp2/3), and 20 (24.4%) did not have a deletion in either gene. In total, 29.3% of individuals had an asymptomatic plasmodial infection and were 3.64 times more likely to have parasites with a double deletion (pfhrp2/3) than patients with clinical malaria (p = 0.02). The high prevalence of parasites with pfhrp2/3 deletions shows the need to implement a surveillance program in this area. Deletions in parasites may be associated with the clinical pattern of the disease in this area. More studies must be carried out to elucidate these findings.

Use of the rapid molecular test for tuberculosis among people deprived of liberty: a scoping review / Uso de la prueba molecular rápida de tuberculosis en personas privadas de libertad: revisión de alcance / Utilização do teste rápido molecular para tuberculose entre pessoas privadas de liberdade: revisão de escopo

ABSTRACT Objective: to map the repercussions of using the rapid molecular test for diagnosing tuberculosis among people deprived of liberty in the scientific literature. Method: this is a scoping review following the recommendations of the Joanna Briggs Institute and PRISMA for Scoping Reviews. The search was conducted using controlled and free vocabulary in the following databases: EMBASE, Scopus, MEDLINE, Cinahl, Academic Search Premier, LILACS and Web of Science, in the Brazilian Digital Library of Theses and Dissertations and Google Scholar. The materials which answered the review question were selected by two independent reviewers based on reading the titles, abstracts and publications. All types of studies and publications were included. The extracted data was subjected to narrative synthesis and presented graphically. Results: a total of 13 among the 461 publications found were included in the review. The studies pointed out the following repercussions of using the rapid molecular test in the prison population: increase in the diagnosis of cases compared to sputum smear microscopy; reduction in diagnosis time, initiating treatment and isolation; identification of strains resistant to antibiotic therapy; reducing the prevalence and occurrence of tuberculosis; high agreement of test results with culture results; lower cost of the test when carried out in groups of samples or when screening is carried out by radiography. Conclusion: the literature indicated that the rapid molecular test is relevant for combating tuberculosis in prison units, so its use should be considered by authorities and managers as a strategic tool for controlling the disease.

RESUMEN Objetivo: mapear las repercusiones del uso de la prueba molecular rápida para el diagnóstico de tuberculosis en personas privadas de libertad en la literatura científica. Método: scoping review, siguiendo las recomendaciones del Joanna Briggs Institute y PRISMA for Scoping Reviews. La búsqueda se realizó utilizando vocabularios controlados y libres en las siguientes bases de datos: EMBASE, Scopus, MEDLINE, Cinahl, Academic Search Premier, LILACS y Web of Science, en la Biblioteca Digital Brasileña de Tesis y Disertaciones y en Google Scholar. Los materiales que respondieron a la pregunta de revisión fueron seleccionados por dos revisores independientes, basándose en la lectura de títulos, resúmenes y publicaciones. Se incluyeron todo tipo de estudios y publicaciones. Los datos extraídos fueron sometidos a síntesis narrativa y presentados gráficamente. Resultados: entre las 461 publicaciones encontradas, 13 fueron incluidas en la revisión. Los estudios señalaron las siguientes repercusiones del uso de la prueba molecular rápida en la población penitenciaria: aumento del diagnóstico de casos en comparación con la baciloscopia de esputo; reducción del tiempo de diagnóstico, inicio de tratamiento y aislamiento; identificación de cepas resistentes a la terapia con antibióticos; reducir la prevalencia y aparición de la tuberculosis; alta concordancia de los resultados de las pruebas con los resultados del cultivo; menor coste de la prueba cuando se realiza en grupos de muestras o cuando el cribado se realiza mediante radiografía. Conclusión: la literatura indicó que la prueba molecular rápida es relevante para el combate a la tuberculosis en las unidades penitenciarias, por lo que su uso debe ser considerado por autoridades y gestores como una herramienta estratégica para el control de la enfermedad.

RESUMO Objetivo: mapear as repercussões da utilização do teste rápido molecular para o diagnóstico de tuberculose entre as pessoas privadas de liberdade junto à literatura científica. Método: revisão de escopo seguiram-se as recomendações do Joanna Briggs Institute e do PRISMA for Scoping Reviews. A busca foi realizada com vocabulários controlados e livres nas bases de dados: EMBASE, Scopus, MEDLINE, Cinahl, Academic Search Premier, LILACS e Web of Science, na Biblioteca Digital Brasileira de Teses e Dissertações e no Google Scholar. Foram selecionados por dois revisores independentes, os materiais que respondiam à pergunta da revisão, a partir da leitura dos títulos, resumos e publicações. Foram incluídos todos os tipos de estudo e publicações. Os dados extraídos foram submetidos à síntese narrativa e apresentados graficamente. Resultados: entre as 461 publicações encontradas, 13 foram incluídas na revisão. Os estudos apontaram as seguintes repercussões da utilização do teste rápido molecular na população prisional: aumento no diagnóstico de casos comparado à baciloscopia; redução no tempo de diagnóstico, início do tratamento e isolamento; identificação de cepas resistentes à antibioticoterapia; redução da prevalência e ocorrência da tuberculose; alta concordância dos resultados do teste com os da cultura; menor custo do teste quando realizado em grupos de amostras ou quando o rastreamento é realizado por radiografia. Conclusão: a literatura apontou que o teste rápido molecular é relevante para o enfrentamento da tuberculose nas unidades prisionais, de modo que a sua utilização deve ser considerada pelas autoridades e gestores como uma ferramenta estratégica para o controle da doença.

Correction to "Performance of a serological IgM and IgG qualitative test for COVID-19 diagnosis: An experimental study in Brazil".

[This corrects the article on p. 100 in vol. 12, PMID: 36196438.].

Performance of the procedure for ultra-rapid extraction and loop-mediated isothermal amplification (PURE-LAMP) method to detect malaria in Haiti.

BACKGROUND: Malaria continues to cause burden in various parts of the world. Haiti, a Caribbean country, is among those aiming to eliminate malaria within a few years. Two surveys were conducted in Haiti during which we aimed to evaluate the performance of the simple and rapid procedure for ultra-rapid extraction-loop-mediated isothermal amplification (PURE-LAMP) method with dried blood spots as an alternative diagnostic method for malaria in the context of low to very low rates of transmission. METHODS: Febrile and afebrile people were recruited from three administrative divisions within Haiti: Nippes, Sud and Grand'Anse, during the summers of 2017 (early August to early September) and 2018 (late July to late August). Their blood samples were tested by microscopy, rapid diagnostic tests (RDT), PURE-LAMP and nested PCR to detect Plasmodium infection. Sensitivity, specificity, positive and negative predictive values and kappa statistics were estimated with the nested PCR results as the gold standard. RESULTS: Among 1074 samples analyzed, a positive rate of 8.3% was calculated based on the nested PCR results. Among febrile participants, the rates in 2017 and 2018 were 14.6% and 1.4%, respectively. Three positives were detected among 172 afebrile participants in 2018 by PURE-LAMP and nested PCR, and all three were from the same locality. There was no afebrile participants recruited in 2017. The PURE-LAMP, RDT and microscopy had respective sensitivities of 100%, 85.4% and 49.4%. All of the testing methods had specificities over 99%. CONCLUSIONS: This study confirmed the high performance of the PURE-LAMP method to detect Plasmodium infection with dried blood spots and recommends its use in targeted mass screening and treatment activities in low endemic areas of malaria.

A multicenter comparative study of the performance of four rapid immunochromatographic tests for the detection of anti-Trypanosoma cruzi antibodies in Brazil.

Diagnosis of Trypanosoma cruzi (T. cruzi) infection in the chronic phase of Chagas disease (CD) is performed by serologic testing. Conventional tests are currently used with very good results but require time, laboratory infrastructure, and expertise. Rapid diagnostic tests (RDTs) are an alternative as the results are immediate and do not require specialized knowledge, making them suitable for epidemiologic studies and promising as a screening tool. Nevertheless, few studies conducted comparative evaluations of RDTs to validate the results and assess their performance. In this study, we analyzed four trades of rapid tests (OnSite Chagas Ab Combo Rapid Test-United States, SD Bioline Chagas AB-United States, WL Check Chagas-Argentina, and TR Chagas Bio-Manguinhos-Brazil) using a panel of 190 samples, including sera from 111 infected individuals, most of whom had low T. cruzi antibody levels. An additional 59 samples from uninfected individuals and 20 sera from individuals with other diseases, mainly visceral leishmaniasis, were included. All tests were performed by three independent laboratories in a blinded manner. Results showed differences in sensitivity from 92.8 to 100%, specificity from 78.5 to 92.4%, and accuracy from 90.5 to 95.3% among the four assays. The results presented here show that all four RDTs have high overall diagnostic ability. However, WL Check Chagas and TR Chagas Bio-Manguinhos were considered most suitable for use in screening studies due to their high sensitivity combined with good performance. Although these two RDTs have high sensitivity, a positive result should be confirmed with other tests to confirm or rule out reactivity/positivity, especially considering possible cross-reactivity with individuals with leishmaniasis or toxoplasmosis.

Evaluation of Histidine-Rich Proteins 2 and 3 Gene Deletions in Plasmodium falciparum in Endemic Areas of the Brazilian Amazon.

Histidine-rich proteins 2 and 3 gene (pfhrp2 and pfhrp3) deletions affect the efficacy of rapid diagnostic tests (RDTs) based on the histidine-rich protein 2 (HRP2), compromising the correct identification of the Plasmodium falciparum species. Therefore, molecular surveillance is necessary for the investigation of the actual prevalence of this phenomenon and the extent of the disappearance of these genes in these areas and other South American countries, thus guiding national malaria control programs on the appropriate use of RDTs. This study aimed to evaluate the pfhrp2 and pfhrp3 gene deletion in P. falciparum in endemic areas of the Brazilian Amazon. Aliquots of DNA from the biorepository of the Laboratory of Basic Research in Malaria, Evandro Chagas Institute, with a positive diagnosis for P. falciparum infection as determined by microscopy and molecular assays, were included. Monoinfection was confirmed by nested-polymerase chain reaction assay, and DNA quality was assessed by amplification of the merozoite surface protein-2 gene (msp2). The pfhrp2 and pfhrp3 genes were amplified using primers for the region between exons 1 and 2 and for all extension of exon 2. Aliquots of DNA from 192 P. falciparum isolates were included in the study, with 68.7% (132/192) from the municipality of Cruzeiro do Sul (Acre) and 31.3% (60/192) from Manaus (Amazonas). Of this total, 82.8% (159/192) of the samples were considered of good quality. In the state of Acre, 71.7% (71/99) showed pfhrp2 gene deletion and 94.9% (94/99) showed pfhrp3 gene deletion, while in the state of Amazonas, 100.0% (60/60) of the samples showed pfhrp2 gene deletion and 98.3% (59/60) showed pfhrp3 gene deletion. Moreover, 79.8% (127/159) of isolates displayed gene deletion. Our findings confirm the presence of a parasite population with high frequencies of pfhrp2 and pfhrp3 gene deletions in the Brazilian Amazon region. This suggests reconsidering the use of HRP2-based RDTs in the Acre and Amazonas states and calls attention to the importance of molecular surveillance and mapping of pfhrp2/pfhrp3 deletions in this area and in other locations in the Amazon region to guarantee appropriate patient care, control and ultimately contribute to achieving P. falciparum malaria elimination.

Cost-effectiveness of rapid diagnostic tests, compared to microscopic tests, for the diagnosis and treatment of gestational malaria in Colombia from an institutional perspective.

BACKGROUND: Gestational malaria is associated with negative outcomes in maternal and gestational health; timely diagnosis is crucial to avoid complications. However, the limited infrastructure, equipment, test reagents, and trained staff make it difficult to use thick blood smear tests in rural areas, where rapid testing could be a viable alternative. The purpose of this study was to estimate the cost-effectiveness of rapid tests type III (Plasmodium falciparum/Plasmodium spp P.f/pan) versus microscopic tests for the diagnosis and treatment of gestational malaria in Colombia. METHODS: Cost-effectiveness analyses of gestational malaria diagnosis from an institutional perspective using a decision tree. Standard costing was performed for the identification, measurement and assessment phases, with data from Colombian tariff manuals. The data was collected from Health Situation Analysis, SIVIGILA and meta-analysis. Average and incremental cost-effectiveness ratio were estimated. The uncertainty was assessed through probabilistic sensitivity analysis. RESULTS: The cost of rapid diagnostic tests in 3,000 pregnant women with malaria was US$66,936 and 1,182 disability adjusted life years (DALYs) were estimated. The cost using thick blood smear tests was US$50,838 and 1,023 DALYs, for an incremental cost-effectiveness of US$ 101.2. The probabilistic sensitivity analysis of rapid diagnostic tests determined that they are highly cost-effective in 70% of the cases, even below the US$1,200 threshold; also, they showed an incremental net monetary benefit of $150,000 when payer's willingness is US$1,000. CONCLUSION: The use of rapid diagnostic tests for timely diagnosis and treatment of gestational malaria is a highly cost-effective strategy in Colombia, with uncertainty analyses supporting the robustness of this conclusion and the increased net monetary benefit that the health system would obtain. This strategy may help in preventing the negative effects on maternal health and the neonate at a low cost.

Digging for care-seeking behaviour among gold miners in the Guyana hinterland: a qualitative doer non-doer analysis of social and behavioural motivations for malaria testing and treatment.

BACKGROUND: Although Guyana has made significant progress toward malaria control, limited access to malaria testing and treatment services threatens those gains. Mining activities create breeding environments for mosquitoes, and the migrant and mobile mining populations are hard to reach with information and services. The Ministry of Public Health (MoPH) has trained volunteers to test and treat malaria cases in remote regions. However, it remains unclear how miners perceive these testers, the services they provide, or what their malaria care-seeking behaviour is in general. To better address these challenges, Breakthrough ACTION Guyana and MoPH conducted qualitative research from October to November 2018 in Regions 7 and 8 in Guyana. METHODS: A total of 109 individuals, 70 miners, 17 other mining camp staff, and 22 other key stakeholders (e.g. community health workers, pharmacists, and regional leadership), participated in semi-structured interviews and focus group discussions. Results were derived using a framework analysis, with an adjusted doer and non-doer analysis, and organized using the integrated behaviour framework. RESULTS: Miners sought MoPH-approved services because of close geographic proximity to testing services, a preference for public service treatment, and a desire to correctly diagnose and cure malaria rather than just treat its symptoms. Those who chose to initiate self-treatment-using unregulated medications from the private and informal sector-did so out of convenience and the belief that self-treatment had worked before. Miners who completed the full MoPH-approved treatment understood the need to complete the treatment, while those who prematurely stopped treatment did so because of medication side effects and a desire to feel better as soon as possible. CONCLUSION: Reasons why miners do and do not pursue malaria testing and treatment services are diverse. These results can inform better MoPH programming and new solutions to improve malaria outcomes in Guyana.

Plasma de convaleciente para el tratamiento de la COVID-19: Protocolo para el acceso y uso en Venezuela / Convalescent Plasma for the Treatment of COVID-19: Protocol for access and use in Venezuela

En diciembre 2019, en Wuhan, China, se registró un aumento inusual de casos de infección respiratoria aguda de rápida progresión y alta letalidad. Al poco tiempo es identificado el agente causal, un coronavirus denominado SARS-CoV-2 y se caracteriza una nueva enfermedad, COVID-19. En ausencia hasta el momento de tratamientos específicos, eficaces y seguros, se justifica explorar alternativas científicamente fundamentadas a nuestro alcance como el uso de Plasma de Convaleciente (PC-CoV19) como coadyuvante para el tratamiento de la COVID-19. El plasma de pacientes recuperados de una enfermedad infecciosa, Plasma de Convaleciente, ha sido utilizado en el tratamiento de patologías infecciosas. Hay antecedentes inmediatos de su uso en enfermedades producidas por otro tipo de coronavirus y se registran experiencias y estudios clínicos con resultados preliminares durante esta pandemia. Quimbiotec, empresa productora de hemoderivados y fármacos recombinantes del Estado venezolano, y el Banco Municipal de Sangre, definen un protocolo para promover condiciones para la aféresis, procesamiento, conservación, almacenamiento, distribución, transfusión y evaluación de la seguridad y eficacia del PC-CoV19 como alternativa en el tratamiento de la COVID-19 en Venezuela. Se incluye la identificación de capacidades y de talento, la estructura física, equipos y especialistas necesarios, así como la definición de procesos para establecer rutinas controladas y auditables para sentar bases del acceso y uso del PC-CoV19 en el Sistema Nacional de Salud de Venezuela y preparar el diseño y ejecución de estudios clínicos. Se presenta el Protocolo y algunos nudos críticos en su ejecución a la fecha, herramientas y estrategias utilizadas para su solución(AU)

On December 2019, in Wuhan, China, there was an unusual increase in cases of a fast-progressing acute respiratory infection with high fatality rate. Soon after, the causing agent is identiied, a coronavirus called SARS-CoV-2, and a new disease, COVID-19 is characterized. Currently, in the absence of specific, effective and safe treatments, it is justified to explore all scientifically based alternatives available to us, such as the use of Convalescent Plasma (PC-CoV19) as acoadjutant treatment of COVID-19.Plasma from patients who have recovered from an infectious disease, Convalescent Plasma, has been used in the treatment of other infectious disease. There is recent history of its use in diseases caused by another type of coronavirus, and clinical experiences and studies have already been published with preliminary results during this pandemic. Quimbiotec, a Venezuelan State public company that produces blood products and recombinant drugs, and Banco Municipal de Sangre, deined a protocol to promote conditions for aphaeresis, processing, conservation, storage, distribution, transfusion, and evaluation of safety and eficacy of PC-CoV19 as an alternative for the treatment of COVID-19 in Venezuela. This protocol includes identification of capacities, physical structure, equipment and skills, talent, professionals needed, as well as a definition of processes to establish controlled and auditable routines to lay the foundations for access and use of PC-CoV19 in the Venezuela Health System, and prepare the design and implementation of clinical studies. The protocol and currently critical points in its implementation, as well as tools and strategies used for its solution, are presented(AU)

External quality assessment for HIV rapid tests: challenges and opportunities in Haiti.

HIV rapid diagnostic tests (RDTs) are instrumental in scaling-up HIV testing services (HTS) in low-income and middle-income countries (LMICs). HIV misdiagnosis is a growing concern in the era of expanded and decentralised access to HTS. External quality assurance (EQA) programme including proficiency testing (PT) for HIV RDTs is a priority to guarantee the accuracy and reliability of the patients' result. Here we are sharing Haiti's 11 years' experience in implementing HIV RDTs EQA programme to help address some of the challenges faced by other LMICs. HTS is expanding beyond laboratory walls and HIV RDTs are increasingly performed by non-laboratory personnel and closer to the community. EQA programmes for HIV RDTs in Haiti have faced significant challenges. In expanded HTS settings, non-laboratory personnel (nurses, aid-nurses) involved in HIV RDT are usually undertrained and participate poorly in PT programs. In more than half of the lab enrolled in the PT programme in Haiti, the panels are always tested by the most experienced technician, defying the purpose of the program which is to evaluate the performance of the technician performing the test daily. EQA programme in Haiti and other LMICs are usually not tailored to address community HIV testing challenges. With decreased funding and absence of government financial commitment to HIV RDTs EQA programmes, more innovative and cost-efficient strategies are sought to ensure the quality of HIV diagnosis in LMICs. Qualified human resources, continuous training, supervision and community-tailored PT programmes remain key components for the success of HIV RDT quality management.

Comparación de los métodos de gota gruesa y tiras de diagnóstico rápido para el diagnóstico de la malaria en Luanda, Angola / Comparison of thick blood smear and rapid test methods for malaria diagnosis in Luanda, Angola

Introducción: a pesar de que se ha logrado reducir la morbilidad y la mortalidad de la malaria en África, esta constituye aún un importante problema de salud en Angola, y su capital, Luanda. Objetivo: comparar la ejecución de la microscopía contra un método de tiras de diagnóstico rápido para el diagnóstico de la malaria. Material y Métodos: se llevó a cabo un estudio de corte transversal para evaluar la precisión de una prueba rápida para el diagnóstico del paludismo. Entre diciembre de 2013 y marzo de 2014; se seleccionaron aleatoriamente 1 000 muestras de sangre de pacientes quienes acudieron a los laboratorios por diagnóstico sospechoso de malaria, las que fueron analizadas por gota gruesa, y una prueba de diagnóstico rápido (SD Bioline Malaria AntigenPf/Pv®). Se evaluó la concordancia, la validez y la seguridad de ambos métodos, y para ello las gotas gruesas, fueron consideradas como la "prueba de oro". Resultados: se obtuvo una mayor frecuencia de positividad con las TDR que con las gotas gruesas en dos de los centros de salud (p<0,05). Al comparar los valores de concordancia, validez y seguridad entre los métodos empleados para el diagnóstico de la malaria se obtuvieron valores de concordancia superiores con la gota gruesa que con las TDR. De la misma forma, la especificidad y los valores predictivos de los positivos también fueron superiores con las gotas gruesas (p<0,01). Conclusiones: este estudio permite considerar esta técnica de diagnóstico rápido como un método adecuado y sensible para diagnosticar infecciones por P. falciparum en Luanda(AU)

Introduction: despite of National programs for control have reduced the morbidity and mortality because of malaria in Africa, this parasitic disease is still an important public health problem in the continent, in the Republic of Angola, and its capital Luanda.Objective: to compare the skills of technicians on malaria microscopy and to compare the microscopy against a rapid diagnostic test (RTD) in health centers from Luanda. Material and Methods: among December 2013 y march 2014, one thousand samples were randomly selected from patients visiting laboratories because of suspected diagnosis of malaria. These samples were observed by 20 technicians in 10 health centers from Luanda. A blood sample was taken by every person in order to be examined by thick smear (TS) and a RTD (SD Bioline Malaria Antigen Pf/Pv®). The concordance, the validity, and safety of both methods were evaluated, and the gold standard was defined by thick smears observed by four malaria expert technicians.Results: the frequency of positivity obtained with RTD was higher than with TSin health centers from Kassequel, Samba, and Km 12 (p<0.05). The comparison of concordance, validity, and safety between used methods for the diagnosis of malaria showed concordance values with TS higher than RTD. The specificity and predictive values for positives were upper with TS than RTD (p<0,01). Conclusions: this study showed the RTDBioline Malaria Ag f/Pv®, is an adequate and sensible method for the diagnosis of P. falciparum infections in Luanda(AU)

International meeting: new diagnostic tests are urgently needed to treat patients with Chagas disease / Reunião internacional: novos testes diagnósticos são necessários urgentemente para tratar pacientes com doença de Chagas

Trypanosoma cruzi infection is often not detected early on or actively diagnosed, partly because most infected individuals are either asymptomatic or oligosymptomatic. Moreover, in most places, neither blood banks nor healthcare units offer diagnostic confirmation or treatment access. By the time patients present clinical manifestations of advanced chronic Chagas disease, specific treatment with current drugs usually has limited effectiveness. Better-quality serological assays are urgently needed, especially rapid diagnostic tests for diagnosis patients in both acute and chronic phases, as well as for confirming that a parasitological cure has been achieved. Some new antigen combinations look promising and it is important to assess which ones are potentially the best, together with their requirements in terms of investigation and development. In August 2007, a group of specialized researchers and healthcare professionals met to discuss the state of Chagas infection diagnosis and to build a consensus for a plan of action to develop efficient, affordable, accessible and easy-to-use diagnostic tests for Chagas disease. This technical report presents the conclusions from that meeting.

A infecção pelo Trypanosoma cruzi não é comumente detectada cedo ou diagnosticada ativamente, em parte porque a maioria dos infectados é assintomática ou oligossintomática e nem os bancos de sangue nem as unidades de saúde oferecem, na maioria dos lugares, nem a confirmação do diagnóstico nem o acesso ao tratamento. Habitualmente, quando os pacientes apresentam manifestações clínicas avançadas da doença crônica o tratamento específico com os medicamentos atuais tem efetividade limitada. São necessárias urgentemente provas sorológicas de melhor qualidade, e em especial provas diagnósticas rápidas, para diagnosticar pacientes na fase aguda e crônica, assim como para confirmar a cura parasitológica. Algumas novas combinações de antígenos são promissoras e é importante avaliar as potencialmente melhores, assim como as suas necessidades em nível de pesquisa e desenvolvimento. Em agosto 2007, um grupo de pesquisadores especializados e profissionais da área da saúde se reuniu para discutir a situação do diagnóstico da infecção chagásica e elaborar um consenso sobre um plano de ação em prol do desenvolvimento de testes diagnósticos eficientes, acessíveis e fáceis de usar. Este informe técnico apresenta as conclusões da reunião.