Teste de antigliadina deaminada IgG para crianças com até 2 anos de idade e com suspeita de doença celíaca / IgG deaminated antigliadin test for children aged 2 years or older with suspected celiac disease

INTRODUÇÃO: A Doença Celíaca (DC) é uma doença autoimune crônica do intestino delgado caracterizada por intolerância permanente ao glúten. A sua prevalência global é de aproximadamente 1%. No Brasil, essa prevalência foi relatada em cerca de 0,54% em crianças (1-14 anos). O rastreamento por sorologia associado à confirmação por biópsia duodenal é padrão ouro para o diagnóstico em adultos e em crianças, mas a biópsia precisa ser bem indicada na prática pediátrica por ser um procedimento invasivo e potencialmente de alto risco. Os testes sorológicos para detectar anticorpos IgA são comumente utilizados, porém indivíduos com deficiência de IgA não podem ser diagnosticados/rastreados por esses testes, justamente porque apresentam déficit na síntese de todas as imunoglobulinas do tipo A. Uma alternativa de triagem para esses indivíduos, bem como para os menores de 2 anos, é a dosagem sérica dos anticorpos IgG, como o teste antigliadina deaminada IgG. PERGUNTA DE PESQUISA: O uso do teste sorológico antigliadina deaminada IgG para triagem é mais acurado e custo-efetivo em pacientes com deficiência de IgA e suspeita de doença celíaca e crianças menores de dois anos quando comparado à triagem com antitransglutaminase IgA e confirmação por biópsia de duodeno por via endoscópica (endoscopia digestiva alta + biópsia)? EVIDÊNCIAS CIENTÍFICAS: Este relatório incluiu oito estudos que avaliaram se o uso do teste sorológico antigliadina deaminada IgG é mais acurado em pacientes com deficiência de IgA e suspeita de doença celíaca de qualquer idade e crianças menores de dois anos quando comparado à biópsia de duodeno por via endoscópica para diagnóstico da doença celíaca. Segundo os resultados das metanálises apresentadas neste relatório, para as análises da acurácia obtidas por meio da sensibilidade e especificidades combinadas, destaca-se a boa especificidade do teste antigliadina deaminada IgG em crianças menores de dois anos, utilizando o ponto de corte determinado pelo fabricante (97,8%; IC95% 95,6% - 98,9%). Já a especificidade combinada foi máxima (100,0%; IC95%:0,0 - 100,0%), potencializando o valor preditivo negativo do teste antigliadina deaminada IgG neste grupo populacional. Estes achados mostram que a adição do teste antigliadina deaminada IgG pode melhorar a acurácia diagnóstica da detecção de DC em crianças menores de dois anos de idade. AVALIAÇÃO ECONÔMICA (AE): Conduziu-se análise de custo-efetividade para comparar os testes diagnósticos com base em suas efetividades e seus custos, por meio da razão de custoefetividade incremental (RCEI). Considerando-se as diferenças observadas no desempenho do teste para crianças menores de dois anos e indivíduos com deficiência de IgA e suspeita de doença celíaca, foram propostas duas árvores de decisão. No caso de indivíduos com deficiência de IgA, a realização de teste antigliadina deaminada associada à EDA com biópsia, comparada à antigliadina deaminada isolada resultaria em razão de custo-efetividade incremental (RCEI) de R$ 108,17 por biópsia evitada. Para a comparação entre antigliadina deaminada isolada e EDA com biópsia, a RCEI seria de R$ 2.063,16 por biópsia evitada. ANÁLISE DE IMPACTO ORÇAMENTÁRIO (AIO): Considerando a população elegível total e suspeita de doença celíaca, o cenário alternativo 01 (market share variando de 30% a 50%) provocaria uma economia de R$ 30.671.133,25, no caso da incorporação do teste antigliadina em substituição aos testes atuais. Já o cenário alternativo 02 (market share de 50% a 70%) de substituição dos testes atuais pelo teste da antigliadina provocaria também economia de R$ 46.018.687,48. Já no cenário em que o teste antigliadina seja adicionado aos testes atuais, ao invés de substituí-los, o impacto orçamentário acumulado em cinco anos seria de R$ 14.410.515,92. CONSIDERAÇÕES FINAIS: Segundo os resultados das metanálises apresentadas neste relatório, destaca-se a boa especificidade do teste de antigliadina deaminada IgG em crianças menores de dois anos, utilizando o ponto de corte determinado pelo fabricante (97,8%; IC95% 95,6% - 98,9%). Já a especificidade combinada foi máxima (100,0%; IC95%:0,0 ­ 100,0%), potencializando o valor preditivo negativo do teste de antigliadina deaminada IgG neste grupo populacional. Para a população de indivíduos com deficiência de IgA, a sensibilidade combinada foi de 76,7% (IC 95%: 54,7% a 90,0%) e a especificidade de 73,3% (IC 95%: 60,6% a 83,0%). A taxa de falsos positivos global correspondeu a 26,7% (IC 95%: 17,0% a 39,4%). Contudo, os achados devem ser interpretados com cautela, uma vez que os estudos primários incluídos foram considerados de qualidade metodológica baixa e muito baixa qualidade da evidência. Um dos estudos incluídos neste relatório é uma revisão sistemática cujo divergiu do encontrado na meta-análise feita pelo grupo elaborador. Enquanto a sensibilidade para o teste antigliadina deaminada IgG em relação à biópsia duodenal foram de 0,96 (IC 95% 0,91 a 0,98) na revisão sistemática, a metaanálise deste relatório teve como resultado 0,48 (IC de 95%: 0,23 a 0,97). Essa divergência está relacionada ao ponto de corte utilizado para a inclusão dos estudos nas metaanálises. Em relação à confiança nos resultados da revisão sistemática em questão, os resultados estão associados a uma baixa confiabilidade. RECOMENDAÇÃO PRELIMINAR DA CONITEC: O tema foi avaliado na 113ª Reunião Ordinária da Conitec em 5 de outubro de 2022. A recomendação inicial foi desfavorável à incorporação do teste de antigliadina deaminada IgG para pessoas com deficiência de IgA por considerar que os testes atualmente disponíveis no SUS já atendem satisfatoriamente a população. Ademais, a recomendação inicial foi favorável à incorporação do teste de antigliadina deaminada IgG para pessoas menores de 2 anos de idade por evitar as hospitalizações necessárias para realização de endoscopia digestiva alta nessa população. CONSULTA PÚBLICA: Foram recebidas 18 contribuições, sendo cinco pelo formulário para contribuições técnico-científicas e 13 pelo formulário para contribuições sobre experiência ou opinião de pacientes, familiares, amigos ou cuidadores de pacientes, profissionais de saúde ou pessoas interessadas no tema. Em relação às contribuições de cunho técnico-científico, quatro concordaram que o teste antigliadina deaminada IgG deve ser incorporado ao SUS e uma não concordou. A Federação Nacional das Associações de Celíacos do Brasil (FENACELBRA) se manifestou contrária à recomendação de incorporação do teste diagnóstico e a favor de seguir a Sociedade Europeia de Gastroenterologia, Hepatologia e Nutrição Pediátrica (ESPGHAN), que sugere que seja realizada a dosagem de IgA total e antitransglutaminase IgA (antitTG) enquanto o paciente estiver consumindo glúten diariamente por cerca de 2 a 3 meses. No caso de crianças com concentração de IgA baixa, a contribuição indicou a necessidade de uma das seguintes sorologias IgG: antigliadina deaminada IgG, antiendomísio IgG ou antitransglutaminase IgG. Um participante foi contrário à premissa de que o resultado para o teste antigliadina deaminada IgG positivo deveria substituir a endoscopia e biópsia, o que foi corroborado por um especialista que participou do grupo elaborador. Dessa forma, uma avaliação econômica e análise de impacto orçamentário adicional foram realizadas com o objetivo de avaliar o impacto dessa premissa. A AE resultou numa RCEI custo-efetiva (R$ 1.254 por QALY ganho) e a AIO resultou em impacto orçamentário positivo de R$ 17.460.094 ao longo de cinco anos. Quanto às contribuições referentes ao formulário de experiência ou opinião, todos foram favoráveis à incorporação. RECOMENDAÇÃO FINAL DA CONITEC: As contribuições da consulta pública foram apresentadas à Conitec por ocasião da 117ª Reunião Ordinária, realizada em 29 de março de 2023. Os membros presentes deliberaram, por unanimidade, recomendar a incorporação do teste de antigliadina deaminada IgG para crianças com até 2 anos de idade e com suspeita de doença celíaca, porque, para essa população, o teste anti-gliadina tem alta acurácia diagnóstica, enquanto para os deficientes de IgA a acurácia diagnóstica foi considerada moderada e de impacto clínico incerto. O teste anti-gliadina deaminada IgG para crianças de até 2 anos de idade deverá ser incorporado conforme Protocolo Clínico do Ministério da Saúde. Por fim, foi assinado o Registro de Deliberação Nº 811 / 2023. DECISÃO: ncorporar, no âmbito do Sistema Único de Saúde - SUS, o teste de antigliadina deaminada IgG para crianças com até 2 anos de idade e com suspeita de doença celíaca, publicada no Diário Oficial da União nº 74, seção 1, página 195, em 18 de abril de 2023.

COVIDIAGNOSTIX: health technology assessment of serological tests for SARS-CoV-2 infection.

OBJECTIVE: In vitro diagnostic tests for SARS-COV-2, also known as serological tests, have rapidly spread. However, to date, mostly single-center technical and diagnostic performance's assessments have been carried out without an intralaboratory validation process and a health technology assessment (HTA) systematic approach. Therefore, the rapid HTA for evaluating antibody tests for SARS-COV-2 was applied. METHODS: The use of rapid HTA is an opportunity to test innovative technology. Unlike traditional HTA (which evaluates the benefits of new technologies after being tested in clinical trials or have been applied in practice for some time), the rapid HTA is performed during the early stages of developing new technology. A multidisciplinary team conducted the rapid HTA following the HTA Core Model® (version 3.0) developed by the European Network for Health Technology Assessment. RESULTS: The three methodological and analytical steps used in the HTA applied to the evaluation of antibody tests for SARS-COV-2 are reported: the selection of the tests to be evaluated; the research and collection of information to support the adoption and appropriateness of the technology; and the preparation of the final reports and their dissemination. Finally, the rapid HTA of serological tests for SARS-CoV-2 is summarized in a report that allows its dissemination and communication. CONCLUSIONS: The rapid-HTA evaluation method, in addition to highlighting the characteristics that differentiate the tests from each other, guarantees a timely and appropriate evaluation, becoming a tool to create a direct link between science and health management.

Serological diagnostic for SARS-CoV-2: an experimental External Quality Assessment Scheme.

OBJECTIVES: Numerous analytical systems, rapidly made available on the market throughout the SARS-CoV-2 pandemic, aim to detect COVID-19, and to continuously update and improve the same systems. Medical laboratory professionals have also developed in-house analytical procedures in order to satisfy the enormous volume of requests for tests. These developments have highlighted the need control the analytical procedures used in order to guarantee patient safety. The External Quality Assessment (EQA) Scheme, an important quality assurance tool, aims to guarantee high standard performance for laboratory and analytical procedures. The aim of the present study was to report on the results collected in an experimental EQA scheme for the serological diagnosis of SARS-CoV-2. METHODS: All qualitative results collected in the different EQA surveys were summarized in order to identify the percentage of laboratory results in relation to typology of antibodies, results and samples. RESULTS: A total of 4,867 data sets were collected. The analysis of EQA data made, demonstrates a better agreement among laboratories results for total Ig than single immunoglobulins (IgG, IgM, IgA) in the case samples positive for SARS-CoV-2, and a wide divergence between IgM results for positive samples (only 34.9% were correct). Results for negative controls and specificity controls demonstrated a better overall agreement than results for positive samples. CONCLUSIONS: Working in collaboration with the IVD manufacturers, laboratory professionals must strive to achieve harmonization of results, and to develop well-defined protocols complying with the ISO 15189 requirements.

Reduced incidence of hepatitis C in 9 villages in rural Egypt: Progress towards national elimination goals.

BACKGROUND & AIMS: Egypt has a major HCV burden and a well established treatment programme, with an ambitious goal of HCV elimination. Our aim was to assess the impact of a comprehensive HCV prevention, test and treat programme on the incidence of new HCV infections in 9 villages in rural Egypt. METHODS: An HCV "educate, test and treat" project was implemented in 73 villages across 7 governorates in Egypt between 06/2015 and 06/2018. In 2018, in 9 of the villages we re-tested individuals who originally tested HCV antibody (HCV-Ab) and HBsAg negative using rapid diagnostic tests (RDTs); confirmatory HCV RNA testing was performed for positive cases. The incidence rate per 1,000 person-years (py) was calculated, and risk factors for incident HCV infections assessed through an interviewer-administered questionnaire in 1:3 age- and gender-matched cases and controls. RESULTS: Out of 20,490 individuals who originally tested HCV-Ab negative in the 9 villages during the 2015-2016 implementation of the "educate, test and treat" programme, 19,816 (96.7%) were re-tested in 2018. Over a median of 2.4 years (IQR 2.1-2.7), there were 19 new HCV infections all of which were HCV RNA positive (incidence rate 0.37/1,000 py) (95% CI 0.24-0.59). Compared to a previous estimate of incidence in the Nile Delta region (2.4/1,000 py) from 2006, there was a substantial reduction in overall incidence of new HCV infections. Exposures through surgery (odds ratio 51; 95% CI 3.5-740.1) and dental procedures (odds ratio 23.8; 95% CI 2.9-194.9) were significant independent predictors of incident infections. CONCLUSIONS: This is the first study to show a substantial reduction in incidence of new HCV infections in a sample of the general population in Egypt following attainment of high testing and treatment coverage. New infections were significantly associated with healthcare-associated exposures. LAY SUMMARY: Egypt has a major national HCV testing and treatment programme with the goal of eliminating HCV infection. We assessed the impact of a comprehensive HCV prevention, test and treat programme in 73 villages that achieved high coverage of testing and treatment on the subsequent incidence of new HCV infections in nine of the villages. We re-tested people who were previously HCV antibody negative and found that the rate of new HCV infections was greatly reduced compared to previous estimates. We also found that exposure through surgery and dental procedures were associated with these new infections. This highlights the importance of continued strengthening of infection control and prevention measures, alongside treatment scale-up.

An economic reappraisal of hepatitis B virus testing strategy for blood donors in Taiwan.

BACKGROUND AND OBJECTIVES: Taiwan is among the few hepatitis B virus (HBV) high-endemic countries that implement universal mini-pool nucleic acid testing (MP-NAT) and hepatitis B surface antigen (HBsAg) testing together with confirmatory individual donor nucleic acid testing (ID-NAT) for its blood supply since 2013. The aim of this study was to reappraise the value of HBsAg test in Taiwan's HBV testing strategy. MATERIALS AND METHODS: A Markov model was constructed, and cost-effectiveness analysis was conducted in order to reappraise the existing HBV screening strategy in Taiwan. RESULTS: The incremental cost-effectiveness ratio (ICER) for the current testing strategy in Taiwan was estimated to be $US 443 154 per quality-adjusted life year (QALY) gained. This is almost six times the willingness-to-pay (WTP) threshold that reflects local preferences. CONCLUSION: Universal HBsAg and MP-8-NAT together with confirmatory ID-NAT testing prevents a significant amount of HBV infections from entering the Taiwan blood supply. However, this comes at a disproportionate increase in cost.

Near Point-of-Care HIV Viral Load: Targeted Testing at Large Facilities.

INTRODUCTION: Point-of-care (POC) technologies in resource-limited settings can circumvent challenges of centralized laboratory testing, improving clinical management. However, higher device costs and uncertain indications for use have inhibited scaling up POC modalities. To address this gap, we investigated the feasibility and cost of targeted near-POC viral load (VL) testing in 2 large HIV clinics in Lilongwe, Malawi. METHODS: VL testing using GeneXpert was targeted for patients suspected of treatment failure or returning to care after a previously elevated VL (>1000 copies/mL). Descriptive analysis of retrospective clinical and cost data is presented. RESULTS: Two thousand eight hundred thirteen near-POC VL tests were conducted. One thousand five hundred eleven (54%) tests were for patients for whom results and reason for the test were documented: 57% (794/1389) of tests were to confirm a previously high VL, and 33% (462/1389) were due to clinical indications. Sixty-one percent (926/1511) of patients had a high VL, of whom 78% (719/926) had a recorded clinical action: 77% (557/719) switched to second line antiretroviral therapy, and 15% (194/719) were referred for intensive adherence counseling. Eighty-two percent (567/687) of patients received a clinical action on the same day as testing. The "all-in" cost was $33.71 for a valid POC VL test, compared with an international benchmark for a centralized VL test of $28.62. CONCLUSION: Targeted, near-POC VL testing was feasible and consistently enabled prompt clinical action. The difference between the "all-in" cost of near-POC VL and centralized testing of $5.09 could be further reduced in an optimized national program by combining targeted near-POC testing and centralized testing.

Cost-effectiveness of serological tests for human visceral leishmaniasis in the Brazilian scenario.

Human visceral leishmaniasis (VL) is a severe and potentially fatal parasitic disease if not correctly diagnosed and treated. Brazil is one of the three countries most endemic for VL and, like most countries affected by this disease, has a large budget constraint for the incorporation of new health technologies. Although different diagnostic tests for VL are currently available in the country, economic studies evaluating diagnostic kits are scarce. The objective of this study was to conduct a cost-effectiveness analysis of the nine available diagnostic tests for human VL in HIV-infected and uninfected patients in Brazil. The perspective of analysis was the Brazilian public health system, and the outcome of interest was "cases diagnosed correctly". The costs of the tests were estimated using the microcosting technique, and comparisons were performed with decision trees. Sensitivity analyses were explored applying variations in cost and effectiveness values. For VL diagnosis among HIV-uninfected patients, using blood samples for the rapid tests (RDTs), the noncommercial direct agglutination test (DAT-LPC) and IT-LEISH were cost-effective tests compared with the baseline OnSite test, but they presented different incremental cost-effectiveness ratios (ICER) of US$7.04 and US$ 205.40, respectively. Among HIV-infected patients, DAT-LPC was the most cost-effective diagnostic test. Comparisons among the tests with the same methodology, based on the low ICER values, revealed that IT-LEISH was the most cost-effective test among the RDTs and the Ridascreen Leishmania Ab among the ELISA tests. These results confirm that cost-effectiveness analyses can provide useful information to support the incorporation of new health technologies within a known scenario and willingness to pay threshold. It was observed that tests based on the same methodologies presented different cost-effectiveness ratios for the same group of patients and that different tests should be recommended for different patient groups. DAT-LPC was an important cost-effective strategy for all patients, requiring minimum laboratorial infrastructure, and IT-LEISH was the cost-effective test for VL screening in HIV-uninfected patients. IT-LEISH and DAT-LPC have complementary profiles and should both be provided by the Brazilian health system.

Comparative assessment of multiple COVID-19 serological technologies supports continued evaluation of point-of-care lateral flow assays in hospital and community healthcare settings.

There is a clear requirement for an accurate SARS-CoV-2 antibody test, both as a complement to existing diagnostic capabilities and for determining community seroprevalence. We therefore evaluated the performance of a variety of antibody testing technologies and their potential use as diagnostic tools. Highly specific in-house ELISAs were developed for the detection of anti-spike (S), -receptor binding domain (RBD) and -nucleocapsid (N) antibodies and used for the cross-comparison of ten commercial serological assays-a chemiluminescence-based platform, two ELISAs and seven colloidal gold lateral flow immunoassays (LFIAs)-on an identical panel of 110 SARS-CoV-2-positive samples and 50 pre-pandemic negatives. There was a wide variation in the performance of the different platforms, with specificity ranging from 82% to 100%, and overall sensitivity from 60.9% to 87.3%. However, the head-to-head comparison of multiple sero-diagnostic assays on identical sample sets revealed that performance is highly dependent on the time of sampling, with sensitivities of over 95% seen in several tests when assessing samples from more than 20 days post onset of symptoms. Furthermore, these analyses identified clear outlying samples that were negative in all tests, but were later shown to be from individuals with mildest disease presentation. Rigorous comparison of antibody testing platforms will inform the deployment of point-of-care technologies in healthcare settings and their use in the monitoring of SARS-CoV-2 infections.

Point-of-Care Tests for Hepatitis B Are Associated with A Higher Linkage to Care and Lower Cost Compared to Venepuncture Sampling During Outreach Screenings in an Asian Migrant Population.

Background: This study compares venepuncture versus point-of-care (POC) HBsAg tests on screening cost and linkage to care in prospective outreach screenings in an Asian population in three major cities in Belgium between 10/2014 and 5/2018. Methods: Two community outreach screening programs were organised between 10/2014 and 5/2018. The first screening program used venepuncture and serologic testing for HBsAg. In the second program, HBsAg was tested in finger stick blood POC tests. Positive results were confirmed during outpatient visits with serologic testing. Linkage to care was defined as having received specialist care follow-up with at least one abdominal ultrasound within three months of screening. Results: For 575 participating individuals, 571 valid results were obtained, 456 with venepuncture, and 115 using POC testing. Overall HBsAg seroprevalence was 6.8%. Linkage to care was higher when using POC testing compared to venepuncture (86% or n = 6/7 versus 34% or n = 11/32; p = 0.020). The POC screening program was economically more attractive with a total cost of € 1,461.8 or € 12.7 per person screened compared to € 24,819 or € 54.0 per person screened when using venepuncture testing. Results and an appointment for specialist care follow-up were given onsite with POC testing, while with venepuncture testing; results were sent within 20-45 days. Conclusion: In an Asian migrant population in Belgium with an HBsAg seroprevalence of 6.8%, HBV screening based on POC tests resulted in lower costs per person screened (76.5% lower), and higher linkage to care (2.5 times).

Implementation of Antibody Rapid Diagnostic Testing versus Real-Time Reverse Transcription-PCR Sample Pooling in the Screening of COVID-19: a Case of Different Testing Strategies in Africa.

Coronavirus disease 2019 (COVID-19) has wreaked havoc across the globe; although the number of cases in Africa remains lower than in other regions, it is on a gradual upward trajectory. To date, COVID-19 cases have been reported in 54 out of 55 African countries. However, due to limited severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) real-time reverse transcription-PCR (rRT-PCR) testing capacity and scarcity of testing reagents, it is probable that the total number of cases could far exceed published statistics. In this viewpoint, using Ghana, Malawi, South Africa, and Zimbabwe as examples of countries that have implemented different testing strategies, we argue that the implementation of sample pooling for rRT-PCR over antibody rapid diagnostic testing could have a greater impact in assessing disease burden. Sample pooling offers huge advantages compared to single test rRT-PCR, as it reduces diagnostic costs, personnel time, burnout, and analytical run times. Africa is already strained in terms of testing resources for COVID-19; hence, cheaper alternative ways need to be implemented to conserve resources, maximize mass testing, and reduce transmission in the wider population.

Assessment of SARS-CoV-2 serological tests for the diagnosis of COVID-19 through the evaluation of three immunoassays: Two automated immunoassays (Euroimmun and Abbott) and one rapid lateral flow immunoassay (NG Biotech).

BACKGROUND: The emergence of new SARS-CoV-2 has promoted the development of new serological tests that could be complementary to RT-PCR. Nevertheless, the assessment of clinical performances of available tests is urgently required as their use has just been initiated for diagnose. OBJECTIVES: The aim of this study was to assess the performance of three immunoassays for the detection of SARS-CoV-2 antibodies. METHODS: Two automated immunoassays (Abbott SARS-CoV-2 CLIA IgG and Euroimmun Anti-SARS-CoV-2 ELISA IgG/IgA assays) and one lateral flow immunoassay (LFIA NG-Test® IgG-IgM COVID-19) were tested. 293 specimens were analyzed from patients with a positive RT-PCR response, from patients with symptoms consistent with COVID-19 but exhibiting a negative response to the RT-PCR detection test, and from control group specimens. Days since symptoms onset were collected from clinical information sheet associated with respiratory tract samples. RESULTS: Overall sensitivity for IgG was equivalent (around 80 %) for CLIA, ELISA and LFIA. Sensitivity for IgG detection, >14 days after onset of symptoms, was 100.0 % for all assays. Overall specificity for IgG was greater for CLIA and LFIA (more than 98 %) compared to ELISA (95.8 %). Specificity was significantly different between IgA ELISA (78.9 %) and IgM LFIA (95.8 %) (p < 0.05). The best agreement was observed between CLIA and LFIA assays (97 %; k = 0.936). CONCLUSION: Excellent sensitivity for IgG detection was obtained >14 days after onset of symptoms for all immunoassays. Specificity was also excellent for IgG CLIA and IgG LFIA. Our study shows that NG-Test® is reliable and accurate for routine use in clinical laboratories.

COVID-19 diagnostics in context.

The coronavirus disease 2019 (COVID-19) pandemic has highlighted the need for different types of diagnostics, comparative validation of new tests, faster approval by federal agencies, and rapid production of test kits to meet global demands. In this Perspective, we discuss the utility and challenges of current diagnostics for COVID-19.

Ethical Implementation of Immunity Passports During the COVID-19 Pandemic.

A number of countries are planning the use of "immunity passports" as a way to ease restrictive measures and allow infected and recovered people to return to work during the COVID-19 pandemic. This paper brings together key scientific uncertainties regarding the use of serological tests to assure immune status and a public health ethics perspective to inform key considerations in the ethical implementation of immunity passport policies. Ill-conceived policies have the potential to cause severe unintended harms that could result in greater inequity, the stigmatization of certain sectors of society, and heightened risks and unequal treatment of individuals due to erroneous test results. Immunity passports could, however, be used to achieve collective benefits and benefits for specific populations besides facilitating economic recovery. We conclude that sector-based policies that prioritize access to testing based on societal need are likely to be fairer and logistically more feasible, while minimizing stigma and reducing incentives for fraud. Clear guidelines need to be set out for which sectors of society should be prioritized for testing, and rigorous mechanisms should be in place to validate test results and identify cases of reinfection.

Integrating testing for chronic strongyloidiasis within the Indigenous adult preventive health assessment system in endemic communities in the Northern Territory, Australia: An intervention study.

BACKGROUND: The life-threatening clinical manifestations of strongyloidiasis are preventable with early detection and effective treatment. The aim of this study was to assess if there was an increase to the number and proportion of persons tested for chronic strongyloidiasis, as a result of integrating Strongyloides stercoralis serology into the existing preventive health assessment system in four Aboriginal health services in endemic communities. METHODOLOGY: A prospective, longitudinal, before-and-after intervention study was conducted in four Aboriginal health services in remote endemically infected communities in the Northern Territory, Australia, from July 2012 to December 2016. The electronic patient information and recall systems enabled the integration of Strongyloides stercoralis serology into the adult preventive health assessment. Strongyloides reports for each health service were extracted half-yearly to examine the number and proportion of persons tested for chronic strongyloidiasis during the study and to measure the effect of the intervention. PRINCIPAL FINDINGS: The number and proportion of persons tested increased significantly during the study. From a total resident population of 3650 Indigenous adults over 15 years of age, 1686 persons (47.4%) were tested. The percentage of adults who had at least one serology test increased in all four health services to between 41% (446/1086) and 81.9% (172/210). Of the 1686 persons tested, 680 positive cases of chronic strongyloidiasis (40.3%) were identified. CONCLUSIONS/SIGNIFICANCE: This population health systems intervention increased the number and proportion of persons tested for chronic strongyloidiasis in four health services in endemically infected communities. This intervention is relevant to other health services with high-risk populations.

An evolving approach to the laboratory assessment of COVID-19.

As the 2019 novel coronavirus disease (COVID-19) outbreak has evolved in each country, the approach to the laboratory assessment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has had to evolve as well. This review addresses the evolving approach to the laboratory assessment of COVID-19 and discusses how algorithms for testing have been driven, in part, by the demand for testing overwhelming the capacity to accomplish such testing. This review focused on testing in the USA, as this testing is evolving, whereas in China and other countries such as South Korea testing is widely available and includes both molecular testing for SARS-CoV-2 as well as serological testing using both enzyme-linked immunosorbent assay methodology and lateral flow immunoassay methodology. Although commercial testing systems are becoming available, there will likely be insufficient numbers of such tests due to high demand. Serological testing will be the next testing issue as the COVID-19 begins to subside. This will allow immunity testing as well as will allow the parameters of the COVID-19 outbreak to be defined.

Assessment of a Serologic Diagnostic Test and Kinetics of Antibody Development in Northern Pike Experimentally Infected with Viral Hemorrhagic Septicemia Virus.

Viral hemorrhagic septicemia virus (VHSV) is an ongoing cause of disease and mortality in freshwater fishes across the Great Lakes region of the Midwestern United States. Antibody detection assays such as enzyme-linked immunosorbent assay (ELISA) are nonlethal serological methods that can have significantly shorter turnaround times than the current validated viral detection diagnostic methodology for VHSV: cell culture with confirmation by polymerase chain reaction (PCR). This study evaluated an ELISA that detects nonneutralizing antinucleocapsid antibodies to VHSV in Northern Pike Esox lucius. Juvenile Northern Pike were experimentally infected with VHSV by intraperitoneal injection. The infected fish were monitored for 12 weeks for signs of disease, and weekly serum samples were obtained. An analysis of the survival data showed that mortality occurred significantly more quickly in inoculated fish than in control fish. Fish that were infected by injection showed a significant increase in antibody response by 2 weeks postinfection. However, variation in the rate and pattern of antibody response among the infected fish was high at any given point. The optimum window for detecting antibodies in Northern Pike is 2-12 weeks postinfection, which generally follows the median time to appearance of clinical signs (21 d postinfection). The receiver-operating characteristic curve analysis showed the ELISA to have a sensitivity of 80.5% and a specificity of 63.2% in Northern Pike, but these values can be adjusted by choosing different percent inhibition cutoffs, which may facilitate the use of the test for specific management goals. The results of this study offer insights into the disease progression and immune kinetics of VHSV, including interindividual variation, which will aid in the management of this economically important virus.

Optimizing the diagnostic capacity for COVID-19 PCR testing for low resource and high demand settings: The development of information-dependent pooling protocol.

AIM: To compare different pooling methods in an attempt to improve the COVID-19 PCR diagnostic capacities. METHOD: We developed a novel information-dependent pooling protocol (indept), based on transmission of less informative sequential pools on to the next pooling cycle to maximize savings. We then compared it to the halving, generalized halving, splitting and hypercube protocols in a simulation study, across variety of scenarios. RESULTS: All five methods yielded various amount of test savings, which mostly depended on the virus prevalence in the population. In situations of low prevalence (up to 5%), indept had the best performance, requiring on average 20% of tests needed for singular testing across scenarios that were analyzed. Nevertheless, this comes at the expense of speed, with the worst-case scenario of indept protocol requiring up to twice the time needed to test the same number of samples in comparison to the hypercube protocol. In order to offset this, we developed a faster version of the protocol (indeptSp), which minimizes the number of terminal pools and manages to retain savings compared to other protocols, despite marginally longer processing times. CONCLUSION: The increasing demand for more testing globally can benefit from application of pooling, especially in resource-restrained situations of the low- and middle-income countries or situations of high testing demand. Singular testing in situations of low prevalence should be systematically discouraged.

Hospital based serological evidence of rickettsial diseases and assessment diagnostic tests of pyrexia of unknown origin.

The present study examined hospital-based serological tests of rickettsial infections and assessment for diagnosis of pyrexia of unknown origin (PUO). Blood samples were tested for Weil Felix antigens, ELISA for scrub typhus group and polymerase chain reaction (PCR) to detect the presence of DNA of spotted and scrub typhus group with the help of specific oligonucleotide. We tested 450 patient samples and found 101 Weil Felix-positive with 15 having ≥320 titres. IgM ELISA identified 32 (7.1%) positive cases. Positive PCR was seen in 13 (2.9%) samples, being only 40.1% of those testing positive for ELISA. Rickettsial infection is predominantly diagnosed through serological evidence in combination with molecular techniques. The Weil Felix test has a number of disadvantages and tends to provide false-positive results in a number of scenarios, especially where scrub typhus and spotted fever are widely distributed.