Assessment of a recombinant protein from Leishmania infantum as a novel tool for Visceral Leishmaniasis (VL) diagnosis in VL/HIV co-infection cases.

Visceral Leishmaniasis and HIV-AIDS coinfection (VL/HIV) is considered a life-threatening pathology when undiagnosed and untreated, due to the immunosuppression caused by both diseases. Serological tests largely used for the VL diagnosis include the direct agglutination test (DAT), ELISA and immunochromatographic (ICT) assays. For VL diagnosis in HIV infections, different studies have shown that the use of the DAT assay facilitates the VL diagnosis in co-infected patients, since the performance of the most widely used ELISA and ICT tests, based on the recombinant protein rK39, are much less efficient in HIV co-infections. In this scenario, alternative recombinant antigens may help the development of new serological diagnostic methods which may improve the VL diagnosis for the co-infection cases. This work aimed to evaluate the use of the recombinant Lci2 antigen, related to, but antigenically more diverse than rK39, for VL diagnosis in co-infected sera through ELISA assays. A direct comparison between recombinant Lci2 and rK39 was thus carried out. The two proteins were first tested using indirect ELISA with sera from VL afflicted individuals and healthy controls, with similar performances. They were then tested with two different sets of VL/HIV co-infected cases and a significant drop in performance, for one of these groups, was observed for rK39 (32% sensitivity), but not for Lci2 (98% sensitivity). In fact, an almost perfect agreement (Kappa: 0.93) between the Lci2 ELISA and DAT was observed for the coinfected VL/HIV patients. Lci2 then has the potential to be used as a new tool for the VL diagnosis of VL/HIV co-infections.

Teste diagnóstico, point of care, de Cryptococcal Antigen Lateral Flow Assay (CRAG-LFA) para detecção de infecção por Cryptococcus e diagnóstico de meningite criptocócica em pessoas vivendo com o vírus da imunodeficiência humana (PVHIV) / Cryptococcal diagnostic test, point of care Lateral Antigen Flow Assay (CRAG-LFA) for detection of Cryptococcus infection and diagnosis of cryptococcal meningitis in people living as human immunodeficiency virus (PVHIV)

CONTEXTO: A criptococose é uma micose sistêmica causada por duas espécies do basidiomiceto encapsulado do gênero Cryptococcus. A infecção acomete principalmente o sistema nervoso central (SNC) e o trato respiratório e sua apresentação mais comum é a meningite criptocócica (MC) ou meningoencefalite. Mundialmente, a MC é resultado de cerca de 15% de todas as mortes relacionadas ao HIV. Estima-se que os 223.100 casos de MC, em 2014, resultaram em 181.100 óbitos, sendo 75% (135.900) na África Subsaariana, seguida pelo Sudeste Asiático e América Latina. Após o surgimento da terapia antirretroviral (TARV) para o HIV, a incidência da criptococose diminuiu significativamente em países desenvolvidos (39%), entretanto, a incidência e a mortalidade pela infecção criptocócica ainda é extremamente alta em países com epidemia de HIV incontrolada e acesso limitado aos medicamentos e aos cuidados de saúde. TECNOLOGIA: Teste diagnóstico, point of care, de Cryptococcal Antigen Lateral Flow Assay (CRAG-LFA). PERGUNTAS DE PESQUISA: 1) O teste CRAG-LFA é sensível e específico na detecção da infecção por Cryptococcus em PVHIV com células CD4+ ≤ 200 cél/mm³ comparado ao teste de aglutinação do látex? 2) O teste CRAG-LFA é sensível e específico no diagnóstico da meningite criptocócica em PVHIV sintomáticos, independente da contagem de células CD4+, se comparado ao teste de aglutinação do látex e tinta da China, em amostra de líquor? EVIDÊNCIAS CLÍNICAS: Para a Pergunta 1 de pesquisa, a estimativa de sensibilidade de CRAG-LFA na detecção da infecção criptocócica foi de 100% e as estimativas de especificidade variaram de 99% a 100%, em relação ao teste de aglutinação por látex (CRAG-LA). Já a sensibilidade combinada dos dois estudos primários incluídos foi 100% (IC95%; 96 - 100) e a especificidade combinada de 99% (IC95%; 99 - 100). Para a Pergunta 2 de pesquisa, a estimativa de sensibilidade de CRAGLFA no diagnóstico de meningite criptocócica em PVHIV foi de 100% e as estimativas de especificidade variaram de 98% a 99%. A sensibilidade combinada dos três estudos primários meta-analisados foi de 100% (IC95%; 92 - 100) e a especificidade combinada de 99% (IC95%; 97 - 100), em relação ao teste de tinta da China. Como evidências analisadas para responder à Pergunta 2 de pesquisa, também foram incluídas duas revisões sistemáticas com meta-análise, a primeira reportou que os valores de sensibilidade e especificidade combinados de CRAG-LFA no líquor foram 98,9% (IC 95%, 97,9% a 99,5%) e 98,9% (IC 95%, 98,0% a 99,5%), respectivamente, já a segunda revisão descreveu que, no líquor, CRAG-LA (10 coortes diagnósticas, 1810 participantes) teve uma sensibilidade resumida de 97,1% (91,9 - 99) e uma especificidade de 99,1% (93,8 - 99,9) enquanto o teste CRAG-LFA (6 coortes diagnósticas, 3.099 participantes) teve uma sensibilidade resumida de 99,5% (97,2 - 99,9) e especificidade de 99,5% (94,2 - 99,9). Embora houvesse alguma evidência estatística fraca de que o CRAG-LFA pode ter melhor sensibilidade no líquor (p = 0,07) do que CRAG-LA, suas especificidades foram comparáveis (p = 0,54). EVIDÊNCIAS ECONÔMICAS: Foi conduzida avaliação econômica do tipo Microssimulação de Monte Carlo, com horizonte temporal de um ano. Considerou-se dois desfechos primários de efetividade: anos de vida e anos de vida ajustados por qualidade (QALY). A análise de custo-efetividade mostrou que os dois testes, CRAG-LA e CRAG-LFA, são custo-efetivos, dominando a alternativa tinta da China e o cenário de não realização da detecção. Para o diagnóstico de meningite criptocócica em PVHIV sintomáticas o uso do teste diagnóstico CRAG-LFA revelou-se custo-efetivo comparado ao teste CRAG-LA, e ao teste tinta da China. A análise de sensibilidade determinística e probabilística indica um favorecimento, na maioria das vezes, do teste CRAG-LFA. ANÁLISE DE IMPACTO ORÇAMENTÁRIO: A análise de impacto orçamentário (AIO) foi realizada para um horizonte temporal de cinco anos, assumindo-se um market share inicial de 20% para o LFA, com incrementos anuais no mesmo valor, chegando a 100% no quinto ano. Para a pergunta 1 de pesquisa a incorporação de LFA teria um custo adicional de aproximadamente 52,7 milhões de reais. Estimou-se também o impacto orçamentário de 100% de adoção da detecção em PVHIV CD4≤ 200 cél/mm³ assintomáticos. Nesse contexto, ocorreria uma economia da ordem de 55 milhões de reais em cinco anos, considerando detecção precoce e tratamento preemptivo, em relação ao custo de tratamento da meningite. Para a pergunta 2, para cada 1.000 PVHIV por ano, em cinco anos teríamos 809 indivíduos tratados a um custo adicional de R$ 10.697.431,27. RECOMENDAÇÕES INTERNACIONAIS: Foi realizada busca por recomendações de uso do teste CRAG-LFA por outras instituições e agências de ATS, a recomendação identificada é proveniente da Organização Mundial da Saúde (OMS). De acordo com a OMS, o diagnóstico e o tratamento precoce da meningite criptocócica são essenciais para reduzir a mortalidade por doença criptocócica em pacientes com infecção pelo vírus da imunodeficiência humana (HIV). A recomendação do órgão é para que os países deem prioridade a ensaios de antígeno criptocócico de diagnóstico rápido, de preferência ensaios de fluxo lateral como o CRAG-LFA, para uso no líquor, soro, plasma ou sangue total. Para adultos, adolescentes e crianças vivendo com HIV com suspeita de um primeiro episódio de meningite criptocócica, a punção lombar imediata com medição da pressão de abertura do líquor e aplicação de um teste diagnóstico rápido para o antígeno criptocócico é recomendado como o preferido abordagem diagnóstica. MONITORAMENTO DO HORIZONTE TECNOLÓGICO: Foram identificados dois outros testes registrados no segundo semestre de 2020 na Anvisa: CRAG Lateral Flow Assay e Biosynex® CryptoPS como testes rápidos CRAG-LFA. Na técnica de LA foram localizados 4 (quatro) registros sanitários na ANVISA. Já no FDA foram encontrados 3 (três) registros sanitários, sendo 1 (um) utilizando a técnica de sonda de DNA. Também foram consultadas as bases de dados de Propriedade Intelectual da WIPO e Espacenet Patent para buscar depósitos de testes de diagnósticos para meningite criptocócica. A consulta buscou os dados recentes de depósitos concedidos entre 2017 e 2020. Foram localizadas 05 patentes concedidas, sendo 04 (quatro) para metodologias em biologia molecular e um (1) para espectroscopia de Raman. CONSIDERAÇÕES FINAIS: Dadas as evidências apresentadas, o teste CRAG-LFA tem potencial custo-efetivo para a detecção da infecção criptocócica e prevenção da mortalidade relacionada à meningite criptocócica em PVHIV. RECOMENDAÇÃO PRELIMINAR: Diante do exposto, a Conitec, em sua 95ª reunião ordinária, realizada no dia 03 de março de 2021, deliberou que a matéria fosse disponibilizada em consulta pública com recomendação preliminar favorável à incorporação no SUS do teste point of care de Cryptococcal Antigen Lateral Flow Assay (CRAG-LFA) para detecção de infecção por Cryptococcus em pessoas vivendo com o vírus da imunodeficiência humana (PVHIV) com CD4+ ≥200 células/mm³ e diagnóstico de meningite criptocócica em PVHIV independente da contagem de células CD4+. Os membros do plenário concordaram, a partir das evidências apresentadas que o teste diagnóstico é custo-efetivo, tem baixo impacto orçamentário e, além disso, foi considerado um teste de fácil aplicação na prática clínica, superando os testes já disponíveis, utilizados como comparadores. A matéria foi disponibilizada em consulta pública. CONSULTA PÚBLICA: A Consulta Pública nº 18/2021 foi realizada entre os dias 18/03/2021 e 06/04/2021. Foram recebidas 82 contribuições, sendo 45 pelo formulário para contribuições técnico-científicas e 38 pelo formulário para contribuições sobre experiência ou opinião de pacientes, familiares, amigos ou cuidadores de pacientes, profissionais de saúde ou pessoas interessadas no tema. Foram consideradas apenas as contribuições encaminhadas no período estipulado e por meio do site da Conitec, em formulário próprio. As contribuições recebidas destacaram as vantagens clínicas do uso do teste CRAG-LFA, considerando economia de recursos, na identificação precoce da condição e tratamento preemptivo. Vantagens relacionadas ao manuseio do teste, sua aplicabilidade e facilidade na interpretação também foram citadas. Não FORAM ADICIONADAS REFERÊNCIAS QUE ALTERASSEM A ANÁLISE DA EVIDÊNCIA APRESENTADA NO RELATÓRIO. RECOMENDAÇÃO FINAL: Os membros do plenário presentes na 97ª reunião ordinária da Conitec, no dia 05 de maio de 2021, deliberaram, por unanimidade, recomendar a incorporação, no SUS, do teste diagnóstico, point of care, de Cryptococcal Antigen Lateral Flow Assay (CRAG-LFA) para detecção da infecção por Cryptococcus em pessoas vivendo com o vírus da imunodeficiência humana (PVHIV) com células CD4+ ≤ 200 cél/mm³ e diagnóstico de meningite criptocócica em PVHIV sintomáticos, independente da contagem de células CD4+, conforme estabelecido pelo Ministério da Saúde. Não foram adicionadas referências que alterassem a análise da evidência apresentada. Foi assinado o Registro de Deliberação nº 610/2021. DECISÃO: Incorporar o teste diagnóstico, point of care, de Cryptococcal Antigen Lateral Flow Assay (CRAG-LFA) para detecção de infecção por Cryptococcus em pessoas vivendo com o vírus da imunodeficiência humana (PVHIV) com CD4+ ³200 células/mm³ e diagnóstico de meningite criptocócica em PVHIV independente da contagem de células CD4+, no âmbito do Sistema Único de Saúde ­ SUS, conforme Portaria nº 28, publicada no Diário Oficial da União nº 108, Seção 1, página 177, em 11 de junho de 2021.(AU)

Performance characteristics and costs of serological tests for brucellosis in a pastoralist community of northern Tanzania.

The control of brucellosis across sub-Saharan Africa is hampered by the lack of standardized testing and the use of tests with poor performance. This study evaluated the performance and costs of serological assays for human brucellosis in a pastoralist community in northern Tanzania. Serum collected from 218 febrile hospital patients was used to evaluate the performance of seven index tests, selected based on international recommendation or current use. We evaluated the Rose Bengal test (RBT) using two protocols, four commercial agglutination tests and a competitive enzyme-linked immunosorbent assay (cELISA). The sensitivity, specificity, positive predictive value, negative predictive value, Youden's index, diagnostic accuracy, and per-sample cost of each index test were estimated. The diagnostic accuracy estimates ranged from 95.9 to 97.7% for the RBT, 55.0 to 72.0% for the commercial plate tests, and 89.4% for the cELISA. The per-sample cost range was $0.69-$0.79 for the RBT, $1.03-$1.14 for the commercial plate tests, and $2.51 for the cELISA. The widely used commercial plate tests performed poorly and cost more than the RBT. These findings provide evidence for the public health value of discontinuing the use of commercial agglutination tests for human brucellosis in Tanzania.

Hospital-based evidence on cost-effectiveness of brucellosis diagnostic tests and treatment in Kenyan hospitals.

Hospitals in Kenya continue to use the Febrile Antigen Brucella Agglutination Test (FBAT) to diagnose brucellosis, despite reports showing its inadequacy. This study generated hospital-based evidence on the performance and cost-effectiveness of the FBAT, compared to the Rose Bengal Test (RBT).Twelve hospitals in western Kenya stored patient serum samples that were tested for brucellosis using the FBAT, and these were later re-tested using the RBT. Data on the running time and cost of the FBAT, and the treatment prescribed for brucellosis, were collected. The cost-effectiveness of the two tests, defined as the cost in US Dollars ($) per Disability Adjusted Life Year (DALY) averted, was determined, and a basic sensitivity analysis was run to identify the most influential parameters. Over a 6-month period, 180 patient serum samples that were tested with FBAT at the hospitals were later re-tested with RBT at the field laboratory. Of these 24 (13.3%) and 3 (1.7%) tested positive with FBAT and RBT, respectively. The agreement between the FBAT and RBT was slight (Kappa = 0.12). Treatment prescribed following FBAT positivity varied between hospitals, and only one hospital prescribed a standardized therapy regimen. The mean $/DALY averted when using the FBAT and RBT were $2,065 (95% CI $481-$6,736) and $304 (95% CI $126-$604), respectively. Brucellosis prevalence was the most influential parameter in the cost-effectiveness of both tests. Extrapolation to the national level suggested that an estimated $338,891 (95% CI $47,000-$1,149,000) per year is currently spent unnecessarily treating those falsely testing positive by FBAT. These findings highlight the potential for misdiagnosis using the FBAT. Furthermore, the RBT is cost-effective, and could be considered as the mainstay screening test for human brucellosis in this setting. Lastly, the treatment regimens must be harmonized to ensure the appropriate use of antibiotics for treatment.

Assessment of Serum Macrophage Migration Inhibitory Factor (MIF) as an Early Diagnostic Marker of Leptospirosis.

The search for valuable early diagnostic markers for leptospirosis is ongoing. The aim of the present study was to evaluate the diagnostic value of macrophage migration inhibitory factor (MIF) for leptospirosis. MIF is an immunoregulatory cytokine secreted by a variety of cell types involved in immune response and the pathogenesis of various diseases. It was previously described as a severity predictor of diseases. Samples of 142 leptospirosis cases, 101 other febrile cases, and 57 healthy controls were studied. The prevalence of leptospirosis was 47.3%. Autumnalis, Australis, and Canicola were the highly prevalent leptospiral serovars with a microscopic agglutination test (MAT) titer in the range 1:80-1:2,560. Enzyme-linked immunosorbent assay (ELISA) of MIF was carried out to measure the serum MIF levels. We found that the serum MIF levels [median, (interquartile range)] were significantly (p < 0.001) elevated in different clinical forms of leptospirosis, such as febrile illness [7.5 ng/ml (5.32-8.97)], pulmonary hemorrhage [13.2 ng/ml (11.77-16.72)], Weil's syndrome [8.8 ng/ml (7.25-9.95)], and renal failure [8.6 ng/ml (7.18-10.5)], than in healthy controls [0.65n g/ml (0.5-1.1)]. Serum MIF had sensitivity, specificity, positive predictive value, and negative predictive value of 100%, >90%, >90%, and 100%, respectively. Receiver operating characteristic (ROC) analysis revealed that the serum MIF levels between leptospirosis cases and control subjects had an area under the curve (AUC) value of >0.9 (p < 0.0001). In leptospirosis patients, elevation of serum MIF was significantly (p < 0.001) higher in severe cases with organ dysfunction [10 ng/ml (7.8-14.5)] than that in mild febrile cases [7.5 ng/ml (5.32-8.97)], with the difference of 2.5 indicating that serum MIF acts as a predictor of leptospirosis severity. Pearson's correlation test demonstrated that the serum MIF level was strongly correlated (r = 0.75, p < 0.0001) with disease progression. The median lethal dose (LD50) of leptospiral lipopolysaccharide (LPS) in BALB/c mice was determined to be 20 mg/kg, which gave rise to endotoxemia. Leptospiral LPS triggered the upregulation of MIF expression at 24 h post-infection, which reached the peak level at 24 h post-treatment in THP-1 cells and showed elevated MIF expressions in different tissues of BALB/c mice at the early stage of infection. Taken together, MIF is an early-phase cytokine that could serve as a rapid diagnostic marker for leptospirosis.

Cost of a new method of active screening for human African trypanosomiasis in the Democratic Republic of the Congo.

BACKGROUND: Human African trypanosomiases caused by the Trypanosoma brucei gambiense parasite is a lethal disease targeted for eradication. One of the main disease control strategies is active case-finding through outreach campaigns. In 2014, a new method for active screening was developed with mini, motorcycle-based, teams. This study compares the cost of two active case-finding approaches, namely the traditional mobile teams and mini mobile teams, in the two health districts of the Democratic Republic of the Congo. METHODS: The financial and economic costs of both approaches were estimated from a health care provider perspective. Cost and operational data were collected for 12 months for 1 traditional team and 3 mini teams. The cost per person screened and diagnosed was calculated and univariate sensitivity analysis was conducted to identify the main cost drivers. RESULTS: During the study period in total 264,630 people were screened, and 23 HAT cases detected. The cost per person screened was lower for a mini team than for a traditional team in the study setting (US$1.86 versus US$2.08). A comparable result was found in a scenario analysis, assuming both teams would operate in a similar setting, with the cost per person screened by a mini team 15% lower than the cost per person screened by a traditional team (1.86 $ vs 2.14$). The main explanations for this lower cost are that mini teams work with fewer human resources, cheaper means of transportation and do not perform the Capillary Tube Centrifugation test or card agglutination test dilutions. DISCUSSION: Active HAT screening with mini mobile teams has a lower cost and could be a cost-effective alternative for active case-finding. Further research is needed to determine if mini mobile teams have similar or better yields than traditional mobile teams in terms of detections and cases successfully treated.

A Low-Cost Micro-Volume Nephelometric System for Quantitative Immunoagglutination Assays.

Immunoassays have been widely used in scientific research and clinical diagnosis due to their versatile detection capability and high specificity. Immunoagglutination assays are kinds of immunoassay, which can simply and rapidly measure the concentration of analytes. In this work, we developed a low-cost micro-volume nephelometric system for quantitative immunoagglutination assays. We used off-the-shelf components to build the system, and the total cost of key components is only about 20 US dollars. The total detection volume in our system was as low as 3 µL, which could significantly reduce the reagent cost and required sample volume. We further evaluated the system performance via the immunoagglutination assay to measure the concentration of C-reactive protein, a plasma protein with levels rising in response to inflammation. The results demonstrated that our system could measure the concentration of analytes with relatively high sensitivity and precision within four minutes, and has high potential to be applied for clinical diagnostic tests.

Comparison of a commercial modified direct agglutination test and a commercial enzyme-linked immunosorbent assay for screening for antibodies against Toxoplasma gondii in naturally exposed domestic cats.

Domestic cats and other felids are definitive hosts for the zoonotic protozoan parasite Toxoplasma gondii. Serology is widely used in epidemiological studies conducted to estimate the proportion of domestic cats that have encountered the parasite. However, a limited number of such studies are available from some regions, including eastern parts of Europe and Russia. Various serological tests have been applied for T. gondii serology for feline samples. Seropositivity indicates previous exposure, and seropositive cats are presumed to have shed oocysts of the parasite earlier and to be chronically infected. In this study, we included a random sample of 200 sera and plasma samples from a larger sampling frame comprising samples from domestic cats from Estonia, where T. gondii is common. The samples, which had been previously screened for anti-T. gondii immunoglobulin G antibodies using a commercial modified direct agglutination test (DAT: Toxo-Screen DA; bioMérieux SA, Marcy-l'Étoile, France), were screened using a commercial enzyme-linked immunosorbent assay (ELISA: VectoToxo-antibodies [VektoTokso-antytila], VectorBest, Novosibirsk, Russian Federation). The cut-off for seropositivity with DAT was titer of 40. Of the 200 samples, 120 (60.0%) tested positive with DAT and 114 (57.0%) tested positive with ELISA; 112 samples (56.0%) tested positive with both tests. Percent agreement of 95.0% and Kappa 0.8971 indicated an almost perfect agreement between the screening results using the two methods. The results of this study can be useful for comparison, evaluation, and interpretation of results obtained with these two tests in seroepidemiological studies and may encourage more studies on the topic from eastern parts of Europe and Russia.

Epidemiological Investigation of Toxoplasma gondii Infections in Commercial Sheep Flock in an Endemic Area for Ocular Toxoplasmosis in Southern Brazil.

INTRODUCTION: Toxoplasma gondii is a widely distributed parasite and of great importance to human and animal health. METHODS: The objective of this study was to assess the prevalence of T. gondii antibodies and risk factors associated with the infection in sheep in the Northwest region of the State of Rio Grande do Sul, Brazil; this region has a very high rate of human ocular toxoplasmosis. Ovine sera were tested by the modified agglutination test (cut-off 1:25). RESULTS: T. gondii antibodies were detected in 70.2% (224 of 319). According to the logistic regression, the most significant factors associated were age and cat access to food stock facility. CONCLUSION: Preventive measures are discussed to reduce the risk of transmission of this zoonosis.

Spatial seroepidemiology, risk assessment and haemato-biochemical implications of bovine trypanosomiasis in low lying areas of Punjab, India.

A cross-sectional study was carried out on 594 bovines (341 buffalo adults, 31 buffalo calves, 163 cattle adults, and 59 cattle calves) to assess the exposure of native bovine population to T. evansi elicited trypanosomiasis in the low-lying areas of Punjab (India). We ruled out the endemicity of the disease with 10.77% (95%CI = 8.53-13.52) sero-positive and 23.56% (95%CI = 20.33-27.15) suspected cases by card agglutination assay. We have presented the spatial distribution of these cases as a guideline to local veterinary practitioners and policy-makers. The categorical assessment of risk factors revealed buffalo adults are the most susceptible group in the state despite insignificant differences in farm management practices. A significant increase in the WBC, platelet, AST and serum iron, and decrease in haemoglobin, haematocrit volume, and serum glucose was recorded in both T. evansi positive and suspected animals.

Exploring global and country-level barriers to an effective supply of leishmaniasis medicines and diagnostics in eastern Africa: a qualitative study.

OBJECTIVES: To understand stakeholders' perceptions of the access barriers to quality-assured diagnostics and medicines for leishmaniasis in the high-burden region of eastern Africa, and to identify key bottlenecks to improve the supply of commodities for neglected tropical diseases. DESIGN: Desk reviews and qualitative in-depth interview study with purposive sampling. METHODS: A landscape analysis through literature and desk review was performed. Next, 29 representatives from international organisations, non-governmental agencies, national control programmes from six countries (Ethiopia, Kenya, Somalia, South Sudan, Sudan and Uganda) and manufacturers were interviewed between May and July 2018. Participants were selected purposively and expanded through a snowballing technique.Data analysis was aided by NVivo, applying the framework method as a part of the thematic content analysis approach. RESULTS: The barriers along the visceral leishmaniasis (VL) supply chain were identified as emerging themes, grouped across supply chain activities and health systems component(s). Stakeholders expressed the perception of progress, but bottlenecks persist. VL medicines, in general, lack multisource production capacity and with small market volume, expansion of suppliers is difficult. Procurement is plagued by forecasting difficulties, complex regulatory policies and procedures, and distribution challenges. Weak communication and coordination across different levels resulted in shortages and loss of trust among different actors. Cross-cutting issues spanned from limited political and resource commitment due to low awareness and limited in-country capacity. However, study respondents were optimistic to pursue several remedies, most importantly to build bridges between supply and demand sides through continued dialogue and collaborations. Diagnostics supply has mostly been overlooked; thus, improved investment in this area is needed. CONCLUSIONS: Addressing supply barriers in eastern Africa requires consistent, specific efforts at the global and national levels, progressing from current partnerships and agreements. Priority actions include pooled procurement, improved forecast, and increased commitment and resources. Sustainability remains an elusive goal, yet to be integrated into discussions moving forward.

Applicability of papain solutions in immunohematology.

OBJECTIVE: To compare the enzyme activity of different presentations of papain solution to validate in-house preparations. METHODS: Two papain solutions were prepared, and the third presentation was a commercial solution. Tests were carried out with samples of red cells typed as weak RhD. RESULTS: In-house prepared papain solutions showed similar enzyme reactivity, and statistically no differences compared to the enzyme activity of the commercial solution. CONCLUSION: Evaluating the cost-benefit ratio, the in-house prepared papain solutions present more economic advantages, and can be incorporated into immunohematological routines as a way to cope with periods of financial crisis and cost-containment policies.

Whole-Cell Biosensor with Tunable Limit of Detection Enables Low-Cost Agglutination Assays for Medical Diagnostic Applications.

Whole-cell biosensors can form the basis of affordable, easy-to-use diagnostic tests that can be readily deployed for point-of-care (POC) testing, but to date the detection of analytes such as proteins that cannot easily diffuse across the cell membrane has been challenging. Here we developed a novel biosensing platform based on cell agglutination using an E. coli whole-cell biosensor surface-displaying nanobodies which bind selectively to a target protein analyte. As a proof-of-concept, we show the feasibility of this design to detect a model analyte at nanomolar concentrations. Moreover, we show that the design architecture is flexible by building assays optimized to detect a range of model analyte concentrations using straightforward design rules and a mathematical model. Finally, we re-engineer our whole-cell biosensor for the detection of a medically relevant biomarker by the display of two different nanobodies against human fibrinogen and demonstrate a detection limit as low as 10 pM in diluted human plasma. Overall, we demonstrate that our agglutination technology fulfills the requirement of POC testing by combining low-cost nanobody production, customizable detection range and low detection limits. This technology has the potential to produce affordable diagnostics for field-testing in the developing world, emergency or disaster relief sites, as well as routine medical testing and personalized medicine.

Applicability of papain solutions in immunohematology / Aplicabilidade de soluções de papaína em imuno-hematologia

ABSTRACT Objective: To compare the enzyme activity of different presentations of papain solution to validate in-house preparations. Methods: Two papain solutions were prepared, and the third presentation was a commercial solution. Tests were carried out with samples of red cells typed as weak RhD. Results: In-house prepared papain solutions showed similar enzyme reactivity, and statistically no differences compared to the enzyme activity of the commercial solution. Conclusion: Evaluating the cost-benefit ratio, the in-house prepared papain solutions present more economic advantages, and can be incorporated into immunohematological routines as a way to cope with periods of financial crisis and cost-containment policies.

RESUMO Objetivo: Comparar a atividade enzimática de diferentes apresentações de solução de papaína para validação de preparados in-house. Métodos: Foram preparadas duas soluções de papaína, e a terceira apresentação tratou-se de uma solução comercial. Os testes comparativos das reações enzimáticas foram realizados com amostras de hemácias tipadas como RhD fraco. Resultados: As soluções de papaína preparadas in-house apresentaram reatividade enzimática semelhante e estatisticamente sem diferenças em comparação com a atividade enzimática da solução comercial. Conclusão: Avaliando-se a relação entre custo e benefício, as soluções de papaína preparadas in-house são economicamente vantajosas, podendo ser incorporadas às rotinas imuno-hematológicas como forma de enfrentamento em períodos de crise financeira e em políticas de retenção de gastos.

Cost-effectiveness of using a rapid diagnostic test to screen for human African trypanosomiasis in the Democratic Republic of the Congo.

New rapid diagnostic tests (RDTs) for screening human African trypanosomiasis (HAT) have been introduced as alternatives to the card agglutination test for trypanosomiasis (CATT). One brand of RDT, the SD BIOLINE HAT RDT has been shown to have lower specificity but higher sensitivity than CATT, so to make a rational choice between screening strategies, a cost-effectiveness analysis is a key element. In this paper we estimate the relative cost-effectiveness of CATT and the RDT when implemented in the Democratic Republic of the Congo (DRC). Data on the epidemiological parameters and costs were collected as part of a larger study. These data were used to model three different diagnostic algorithms in mobile teams and fixed health facilities, and the relative cost-effectiveness was measured as the average cost per case diagnosed. In both fixed facilities and mobile teams, screening of participants using the SD BIOLINE HAT RDT followed by parasitological confirmation had a lower cost-effectiveness ratio than in algorithms using CATT. Algorithms using the RDT were cheaper by 112.54 (33.2%) and 88.54 (32.92%) US dollars per case diagnosed in mobile teams and fixed health facilities respectively, when compared with algorithms using CATT. Sensitivity analysis demonstrated that these conclusions were robust to a number of assumptions, and that the results can be scaled to smaller or larger facilities, and a range of prevalences. The RDT was the most cost-effective screening test in all realistic scenarios and detected more cases than CATT. Thus, on this basis, the SD BIOLINE HAT RDT could be considered as the most cost-effective option for use in routine screening for HAT in the DRC.

Seroepidemiology and risk assessment of Toxoplasma gondii infection in captive wild birds and mammals in two zoos in the North of Portugal.

Toxoplasmosis, caused by the protozoan Toxoplasma gondii, is one of the most widespread zoonoses in the world. It can affect most warm-blooded animals but only felids are its definitive hosts. We determined seroprevalence and associated risk factors in birds and mammals kept in two zoological parks in northern Portugal. Sera from 77 birds and 42 mammals were assayed for the presence of T. gondii antibodies by the modified agglutination test (MAT, cut-off titre 20); 34.5% (41/119) were seropositive. All seropositive animals were apparently healthy except one seropostive mandarin (Aix galericulata) which had chorioretinitis. This is the first report on T. gondii seroprevalence in wild animals in captivity in Portugal. The present findings indicate a widespread exposure of zoo animals in Portugal to T. gondii.

A targeted door-to-door strategy for sleeping sickness detection in low-prevalence settings in Côte d'Ivoire.

Significant efforts to control human African trypanosomiasis (HAT) over the three past decades have resulted in drastic reductions of disease prevalence in Côte d'Ivoire. In this context, the costly and labor-intensive active mass screening strategy is no longer efficient. In addition to a more cost-effective passive surveillance system being implemented in this low-prevalence context, our aim was to develop an alternative targeted active screening strategy. In 2012, we carried out a targeted door-to-door (TDD) survey focused on the immediate vicinities of former HAT patients detected in the HAT focus of Bonon and compared the results to those obtained during classical active mass screening (AMS) surveys conducted from 2000 to 2012 in the same area. The TDD that provides a friendlier environment, inviting inhabitants to participate and gain awareness of the disease, detected significantly more HAT cases than the AMS. These results suggest that the TDD is an efficient and useful strategy in low-prevalence settings where very localized transmission cycles may persist and, in combination with passive surveillance, could help in eliminating HAT.

Use of Treponemal Screening Assay Strength of Signal to Avoid Unnecessary Confirmatory Testing.

BACKGROUND: Our reverse syphilis testing algorithm consists of a treponemal IgG multiplex flow immunoassay (MFI) followed by both rapid plasma reagin titer and the Treponema pallidum particle agglutination (TPPA) test on specimens with a reactive MFI result. We report here the impact of a modified reverse algorithm, in which the strength of signal of the MFI is used to avoid unnecessary TPPA testing. METHODS: The Bioplex syphilis IgG MFI was used as the syphilis screening assay, and specimens with equivocal (antibody index 0.9 or 1.0), or reactive (antibody index ≥ 1.1) results were further tested by rapid plasma reagin titer and TPPA test. We performed a retrospective, descriptive analysis of all specimens received for syphilis screening between January and May of 2014. A cost analysis was performed, taking into account labor and reagent expenses. RESULTS: In our diverse patient population consisting of high-risk incarcerated persons, low-risk obstetrical/gynecological patients and high-risk miscellaneous clinic and inpatients, 430 (65%) of 665 MFI-positive specimens had antibody indices of 8 or greater. Greater than 99% of these specimens were reactive by the TPPA test. Avoiding TPPA testing of specimens with an MFI antibody index ≥8 would save over US $4800 annually in laboratory costs. CONCLUSIONS: The TPPA testing is unnecessary on specimens with MFI antibody indices ≥8. This would substantially reduce the TPPA testing volume and also reduce laboratory expenses.

Underestimation of Leptospirosis Incidence in the French West Indies.

BACKGROUND: Leptospirosis is a neglected zoonosis affecting mainly tropical and subtropical regions worldwide, particularly South America and the Caribbean. As in many other countries, under-reporting of cases was suspected in the French West Indies because of inadequate access to diagnostic tests for the general population. METHODOLOGY/PRINCIPAL FINDINGS: In order to estimate the real incidence of leptospirosis in Guadeloupe and Martinique, a study was performed in 2011 using the three prevailing available biological tests for diagnosis: Microscopic Agglutination Test (MAT), IgM ELISA and PCR. The study investigated inpatients and outpatients and used active case ascertainment from data provided by a general practitioners' sentinel network. The epidemiology of the disease was also described in terms of severity and demographic characteristics. Leptospirosis incidence was estimated at 69.4 (95%CI 47.6-91.1) and 60.6 (95%CI 36.3-85.0) annual cases per 100,000 inhabitants in Guadeloupe and Martinique, respectively, which was 3 and 4 times higher than previous estimations. CONCLUSION/SIGNIFICANCE: Inclusion of PCR and IgM ELISA tests for diagnosis of leptospirosis resulted in improved sensitivity in comparison with MAT alone. Our results highlighted the substantial health burden of the disease in these two territories and the importance of access to appropriate laboratory tests. Based on our results, PCR and IgM ELISA tests have now been included in the list of tests reimbursed by the national system of social security insurance in France. Our results also underline the relevance of implementing an integrated strategy for the surveillance, prevention and control of leptospirosis in the French West Indies.

Study of implementation and direct cost estimates for diagnostic tests for human visceral leishmaniasis in an urban area in Brazil / Estudo da implantação e estimativas de custo direto de testes diagnósticos para leishmaniose visceral humana em uma área urbana no Brasil / Estudio de la implementación y el costo directo estimado de pruebas de diagnóstico de la leishmaniasis visceral humana en una zona urbana en Brasil

Abstract This work reports the process and costs of comprehensively implementing two tests to decentralize the diagnosis of visceral leishmaniasis (VL) in an endemic city in Brazil: a rapid test (IT LEISH) and a direct agglutination test (DAT-LPC). The implementation began by training health professionals to perform the tests. Estimation of the training costs considered the proportional remuneration of all professionals involved and the direct costs of the tests used for training. The study was conducted between November 2011 and November 2013. During that time, 17 training sessions were held, and 175 professionals were trained. The training cost for each professional was US$ 7.13 for the IT LEISH and US$ 9.93 for the DAT-LPC. The direct costs of the IT LEISH and DAT-LPC were estimated to be US$ 6.62 and US$ 5.44, respectively. This first evaluation of the implementation of these diagnostic tests indicates the feasibility of decentralizing both methods to extend access to VL diagnosis in Brazil.

Resumo Este trabalho relata o processo e os custos da implantação de dois testes para descentralizar o diagnóstico da leishmaniose visceral (LV) em um município endêmico no Brasil: um teste rápido (IT LEISH) e um teste de aglutinação direta (DAT-LPC). A implantação iniciou com o treinamento dos profissionais de saúde do município na realização dos testes diagnósticos. Os itens incluídos nas estimativas de custo das capacitações foram a remuneração proporcional de todos os profissionais envolvidos e os custos diretos dos testes usados. O estudo foi conduzido entre novembro de 2011 e novembro de 2013. Durante esse período, 17 capacitações foram realizadas e 175 profissionais treinados. O custo relacionado a cada profissional de saúde capacitado na realização do IT LEISH foi de US$ 7,13 e na realização do DAT-LPC, de US$ 9,93. O custo direto do IT LEISH e do DAT-LPC foi estimado em US$ 6,62 e US$ 5,44, respectivamente. Esta primeira avaliação da implantação desses dois testes aponta para a viabilidade da descentralização de ambos os métodos, que aumentam o acesso ao diagnóstico da LV no Brasil.

Resumen Este trabajo relata la puesta en funcionamiento y los costos de pruebas de diagnóstico de VL en un municipio endémico en Brasil: el test rápido (IT LEISH) y la prueba de aglutinación directa (DAT-LPC). Esta puesta en marcha comenzó por capacitar al personal sanitario del municipio para la realización de las pruebas. Para estimar los costos de la capacitación, se consideró la remuneración proporcional de todo el personal involucrado y los costos directos derivados de la aplicación de las pruebas. El estudio fue realizado entre noviembre de 2011 y noviembre de 2013. En ese periodo se realizaron 17 capacitaciones y se formaron 175 profesionales. Se calcula que el costo derivado de capacitar cada profesional para realizar el IT LEISH fue de 7.13 US$ y 9.93 US$ para el DAT-LPC. Los costos directos del IT LEISH y del DAT-LPC se estimaron en 6,62 US$ y 5,44 US$ respectivamente. La primera evaluación de la puesta en funcionamiento de las dos pruebas en este municipio señala que es viable descentralizar su realización, lo que amplía el acceso al diagnóstico de la VL en Brasil.