ABSTRACT
Combination COVID-19/influenza rapid tests provide a way to quickly and accurately differentiate between the two infections. The goal of this economic evaluation was to assess the cost and health benefits of a combination COVID-19/influenza Rapid Diagnostic Test (RDT) vs. current standard-of-care in the Brazilian private healthcare setting. A dual decision tree model was developed to estimate the impact of rapid differentiation of COVID-19 and influenza in a hypothetical cohort of 1,000 adults with influenza-like illness in an ambulatory healthcare setting. The model compared the use of a combination COVID-19/influenza RDT to Brazil standard diagnostic practice of a COVID-19 RDT and presumptive influenza diagnosis. Different levels of influenza prevalence were modeled with co-infection estimated as a function of the COVID-19 prevalence. Outcomes included accuracy of diagnosis, antiviral prescriptions and healthcare resource use (hospital bed days and ICU occupancy). Depending on influenza prevalence, considering 1,000 patients with influenza-like illness, a combination RDT compared to standard practice was estimated to result in between 88 and 149 fewer missed diagnoses of influenza (including co-infection), 161 to 185 fewer cases of over-diagnosis of influenza; a 24 to 34% reduction in hospital bed days and a 16 to 26% reduction in ICU days. In the base case scenario (20% influenza, 5% COVID-19), the combination RDT was estimated to result in cohort cost savings of $99. Based upon a de novo economic model, this analysis indicates that use of a combination RDT could positively impact influenza antiviral prescriptions and lower healthcare resource use.
Subject(s)
COVID-19 , Influenza, Human , Humans , COVID-19/diagnosis , Brazil/epidemiology , Influenza, Human/diagnosis , Influenza, Human/economics , Cost-Benefit Analysis , Adult , SARS-CoV-2 , COVID-19 Testing/economics , COVID-19 Testing/methods , Coinfection , Rapid Diagnostic TestsABSTRACT
All malaria-endemic countries in the Region of the Americas have taken on the challenge of eliminating the disease and have focused their health programs and strategies on that goal. This technical note provides guidance on actions to expand access to malaria diagnosis and treatment. Access to diagnosis is the foundation of the entire response to the disease. Despite repeated calls and efforts emphasizing the importance of early diagnosis and treatment for malaria elimination in the Americas, significant gaps remain. Lack of detection and/or late detection of cases undoubtedly continue to be factors that perpetuate malaria transmission in the Region. In areas with malaria transmission, diagnosis and treatment need to be available as close to people as possible: at the first point of contact with the health system, and in hard-to-reach areas, within the community itself. The Pan American Health Organization (PAHO) proposes a framework for action to improve access to malaria diagnosis and treatment based on expanded access to diagnosis, including expanded use of rapid diagnostic tests (RDTs) and immediate comprehensive treatment. This framework considers diagnostic methods and antimalarial drugs to be public goods. To achieve this change in malaria operations, it will be necessary to involve many more actors from the health system, affected communities, and society in general in malaria diagnosis and treatment. This strategy calls for an expansion of the diagnosis-treatment (DT) component of the Diagnosis, Treatment, Investigation, and Response (DT-IR) strategy that PAHO and partners in the Region have been promoting for malaria elimination in the Americas.
Subject(s)
Malaria , Rapid Diagnostic Tests , Early Diagnosis , Time-to-Treatment , Vector Borne DiseasesABSTRACT
BACKGROUND: Opportunistic infections (OIs) are common causes of mortality among people living with HIV (PLHIV). We determined prevalence and 30-day mortality due to histoplasmosis, cryptococcosis, and TB in PLHIV with advanced HIV disease (AHD). METHODS: PLHIV 18 years and older, with a CD4 + T-cell count of less than 350 cells/mm3 newly diagnosed with HIV infection or re-engaged in care after being without ART for more than 90 days (Group A). The second group included symptomatic PLHIV regardless of ART status or CD4 + T-cell count (Group B); all followed for 30 days. Detection of Histoplasma Ag (HisAg) in urine was done by enzyme immunoassay (EIA), Cryptococcus antigen (CrAg) was detected in serum and cerebrospinal fluid (CSF) specimens by lateral flow assay (LFA), and lipoarabinomannan (LAM) detection in urine was by LFA (TB LAM) and in sputum by GeneXpert for diagnosis of Mycobacterium infections. RESULTS: From August 2021 to June 2022, 491 PLHIV were enrolled; 482 (98%) had a CD4 + T-cell result, and 381 patients (79%) were classified with AHD according to CD4 + T-cell count (< 200 CD4/mm3). Frequency of an OI was 38% (n = 145/381). Antigen test positivity rate was 16% (72/467) for TB-LAM, 9% (43/464) for HisAg, and 11% (51/484) for CrAg. Twenty-one of 34 (62%) patients receiving CSF CrAg tests were positive, confirming meningitis. Significant differences in 30-day mortality were observed in patients with an OI (16%) vs. no OI (7%) (p = 0.002). Mortality was highest in patients with histoplasmosis (25%), co-infection (22%), cryptococcosis (18% overall; 19% for cryptococcal meningitis), and TB (10%). CONCLUSIONS: TB and fungal OIs, including co-infection, were common in PLHIV in Paraguay and had high associated mortality. Laboratories and health facilities need access to CD4 + T-cell testing and rapid diagnostic assays.
Subject(s)
Coinfection , Cryptococcosis , HIV Infections , Histoplasmosis , Opportunistic Infections , Tuberculosis , Humans , HIV Infections/epidemiology , Histoplasmosis/diagnosis , Histoplasmosis/epidemiology , Rapid Diagnostic Tests , Paraguay/epidemiology , Cryptococcosis/complications , Cryptococcosis/diagnosis , Cryptococcosis/epidemiology , Tuberculosis/complications , Tuberculosis/diagnosis , Tuberculosis/epidemiology , Antigens, FungalABSTRACT
BACKGROUND: Chagas disease (CD), caused by the parasite Trypanosoma cruzi, is the most important endemic anthropozoonosis in Argentina. Since 2010, the World Health Organization has highlighted the urgent need to validate diagnostic systems that allow rapid detection of T. cruzi, infection in primary healthcare centers. Serological rapid diagnostic tests (RDTs) for T. cruzi, infection could be used to improve case management, as RDTs do not require specialized laboratories or highly trained staff to use them. We aimed to generate unbiased performance data of RDTs in Argentina, to evaluate their usefulness for improving T. cruzi, diagnosis rates. METHODS AND PRINCIPAL FINDINGS: This is a retrospective, laboratory-based, diagnostic evaluation study to estimate the clinical sensitivity/specificity of four commercially available RDTs for T. cruzi, using the Chagas disease diagnostic algorithm currently used in Argentina as the reference standard. In total, 400 serum samples were tested, 200 from individuals with chronic T. cruzi infection and 200 from individuals not infected with T. cruzi. All results were registered as the agreement of at least two operators who were blinded to the reference standard results. The sensitivity estimates ranged from 92.5-100% (95% confidence interval (CI) lower bound 87.9-98.2%); for specificity, the range was 76-96% (95% CI lower bound 69.5-92.3%). Most RDTs evaluated showed performances comparable with the reference standard method, showing almost perfect concordance (Kappa 0.76-0.92). CONCLUSIONS: Our study demonstrates that, under controlled laboratory conditions, commercially available RDTs for CD have a performance comparable to the Argentinian diagnostic algorithm, which is based on laboratory-based serological tests. For the next stage of our work, the RDTs will be evaluated in real-world settings.
Subject(s)
Chagas Disease , Trypanosoma cruzi , Humans , Argentina/epidemiology , Retrospective Studies , Urban Population , Rapid Diagnostic Tests , Chagas Disease/diagnosis , Chagas Disease/epidemiology , Antibodies , Sensitivity and Specificity , Antibodies, ProtozoanABSTRACT
Todos los países de la Región de las Américas en los que la malaria es endémica han asumido el reto de eliminar la enfermedad y de poner en marcha intervenciones para orientar sus programas y estrategias de salud en esa dirección. Esta nota conceptual brinda orientación en materia de acciones destinadas a ampliar el acceso al diagnóstico y tratamiento de la malaria, siendo al acceso al diagnóstico la base de toda la respuesta a la malaria. En las zonas con transmisión de malaria, el diagnóstico y el tratamiento tienen que estar disponibles lo más cerca posible de las personas, en el primer punto de contacto con el sistema de salud y, en las zonas de difícil acceso, en la propia comunidad. Por eso, la Organización Panamericana de la Salud (OPS) propone un marco de acción para mejorar el acceso al diagnóstico y el tratamiento de la malaria basado en la ampliación del acceso al diagnóstico que incluye la expansión del uso de pruebas de diagnóstico rápido y el tratamiento completo inmediato. El marco considera el diagnóstico y los antimaláricos como bienes públicos. Para lograr este cambio será necesario involucrar a muchos más actores del sistema de salud, de las comunidades afectadas y de la sociedad en general en el diagnóstico y el tratamiento de la malaria. Esta estrategia es un llamado a expandir en todas las áreas con malaria el componente diagnóstico-tratamiento (DT) de la estrategia de diagnóstico, tratamiento, investigación y respuesta (DT-I-R) que la OPS y los socios de la Región vienen promoviendo para la eliminación de la malaria en las Américas.
Subject(s)
Malaria , Rapid Diagnostic Tests , Early Diagnosis , Time-to-Treatment , Vector Borne DiseasesABSTRACT
Rapid Diagnostic Tests (RDT) are useful to identify syphilis cases, particularly for hard-to-reach populations and if laboratory services are scarce. However, RDT performance may be suboptimal. We aimed to assess the sensitivity and specificity of a syphilis RDT using well-characterized blood donors' samples. We categorized samples from 811 blood donors into five groups: 1 - Samples with reactive Chemiluminescence (QML), FTA-Abs, and VDRL; 2 - Samples with reactive QML and FTA-Abs, and nonreactive VDRL; 3 - Samples with reactive QML, and nonreactive for other markers (false-positives); 4 - Controls with nonreactive QML; and 5 - Samples reactive for HIV, with nonreactive QML. Sensitivity was tested in groups 1 (overall and according to VDRL titers) and 2; specificity was tested in groups 3â5. The RDT had high specificity, even in samples reactive for HIV. The sensitivity was high (91.9%) in samples with reactive VDRL but varied between 75.0%â100% according to VDRL titers. The overall sensitivity was lower (81.3%) in samples with reactive FTA-Abs and nonreactive VDRL. The RDT is a useful tool to detect active syphilis but may be more limited for cases with very early or remote infection, or those with prior treatment. When higher sensitivity is needed, additional strategies including recurrent testing or laboratory-based tests may be required.
Subject(s)
HIV Infections , Syphilis , Humans , Syphilis/diagnosis , Blood Donors , Rapid Diagnostic Tests , Syphilis Serodiagnosis , Sensitivity and Specificity , HIV Infections/diagnosisABSTRACT
Laboratory-based case confirmation is an integral part of measles surveillance programmes; however, logistical constraints can delay response. Use of RDTs during initial patient contact could enhance surveillance by real-time case confirmation and accelerating public health response. Here, we evaluate performance of a novel measles IgM RDT and assess accuracy of visual interpretation using a representative collection of 125 sera from the Brazilian measles surveillance programme. RDT results were interpreted visually by a panel of six independent observers, the consensus of three observers and by relative reflectance measurements using an ESEQuant Reader. Compared to the Siemens anti-measles IgM EIA, sensitivity and specificity of the RDT were 94.9% (74/78, 87.4-98.6%) and 95.7% (45/47, 85.5-99.5%) for consensus visual results, and 93.6% (73/78, 85.7-97.9%) and 95.7% (45/47, 85.5-99.5%), for ESEQuant measurement, respectively. Observer agreement, determined by comparison between individuals and visual consensus results, and between individuals and ESEQuant measurements, achieved average kappa scores of 0.97 and 0.93 respectively. The RDT has the sensitivity and specificity required of a field-based test for measles diagnosis, and high kappa scores indicate this can be accomplished accurately by visual interpretation alone. Detailed studies are needed to establish its role within the global measles control programme.
Subject(s)
Measles virus , Measles , Humans , Brazil/epidemiology , Rapid Diagnostic Tests , Reproducibility of Results , Reading , Immunoglobulin M , Antibodies, Viral , Measles/diagnosis , Measles/epidemiologyABSTRACT
BACKGROUND: Chagas disease is a public health challenge in Colombia, where only an estimated 1.2% of people at risk have accessed diagnosis, while less than 0.5% of affected people have obtained treatment. The development of simplified diagnostic algorithms would enable progress in access to diagnosis; however, the current diagnostic algorithm relies on at least two laboratory-based tests that require qualified personnel, processing equipment, and infrastructure, which are still generally lacking at the primary care level. Rapid diagnostic tests (RDTs) for Chagas disease could simplify diagnosis, but their performance in the epidemiological context of Colombia is not well known. METHODOLOGY: A retrospective analytical observational study of RDTs was performed to estimate the operational characteristics of 11 commercially available RDTs designed for in vitro detection of anti-T. cruzi IgG antibodies. The study was performed under controlled laboratory conditions using human serum samples. PRINCIPAL FINDINGS: Eleven RDTs were assessed, ten using 585 serum samples and one using 551 serum samples. Employing the current national diagnostic algorithm as a reference standard for serological diagnosis of chronic infection, the sensitivity of the assessed RDTs ranged from 75.5% to 99.0% (95% CI 70.5-100), while specificity ranged from 70.9% to 100% (95% CI 65.3-100). Most tests (7/11, 63.6%) had sensitivity above 90%, and almost all (10/11, 90.9%) had specificity above 90%. Five RDTs had both sensitivity and specificity above 90%. CONCLUSIONS/SIGNIFICANCE: The evaluation of these 11 commercially available RDTs under controlled laboratory conditions is a first step in the assessment of the diagnostic performance of RDTs in Colombia. As a next step, field studies will be conducted on available RDTs with sensitivity and specificity greater than 90% in this study, to evaluate performance in real world conditions, with the final goal to allow simplified diagnostic algorithms.
Subject(s)
Chagas Disease , Rapid Diagnostic Tests , Humans , Colombia/epidemiology , Retrospective Studies , Chagas Disease/diagnosis , AntibodiesABSTRACT
A prevalência de HIV em travestis e mulheres transexuais (TrMT) é desproporcionalmente maior quando comparada com a população geral do Brasil. O objetivo deste estudo foi analisar por meio de ensaios molecular e sorológicos convencionais para o diagnóstico da infecção pelo HIV amostras de sangue de uma população TrMT de cinco capitais brasileiras que apresentaram resultado reagente em testes rápidos (TR). Um total de 435 amostras com resultado reagente em pelo menos um TR foi encaminhado ao laboratório de referência do estado de São Paulo o Instituto Adolfo Lutz (IAL) para que fossem analisadas, por meio de testes laboratoriais convencionais. Das amostras avaliadas, 99,3% (432/435) foram reagentes para HIV nos testes laboratoriais convencionais, e destas, 22,7% (98/432) apresentaram carga viral HIV-1 acima de 5.000 cópias/mL e 77,3% (334/432) mostraram-se reagentes em testes sorológicos (imunoensaio de quimioluminescência ou ELISA e imunoblot rápido). As três amostras restantes (0,7%) foram classificadas como "indeterminada para HIV", com base em ensaios molecular e sorológicos convencionais. A sensibilidade analítica dos diferentes ensaios molecular e sorológicos utilizados neste estudo pode ter variado pela influência da imunossupressão viral do HIV-1 resultante da terapia antirretroviral (TARV). Estudos complementares são necessários para melhor entender o impacto da terapia no diagnóstico do HIV
HIV prevalence among travestis and transgender women (TrTW) is disproportionately higher when compared to the overall Brazilian population. The objective of this study was to evaluate, through conventional serological and molecular tests for the diagnosis of HIV infection, blood samples of TrTW residents of five Brazilian capitals with previous reactive HIV point-of-care rapid tests (RT). A total of 435 samples with at least one reactive HIV result on point-of-care tests were sent to the HIV reference laboratory in São Paulo State the Adolfo Lutz Institute for further evaluation by conventional laboratory tests. From total, 432 (99.3%) samples were reactive for HIV infection in conventional laboratory assays, comprising 98/432 (22.7%) with HIV-1 viral load over 5,000 copies/ml, and 334/432 (77.3%) reactive to serological tests (chemiluminescence immunoassay or ELISA, and rapid immunoblotting). The three remaining samples (0.7%) were classified as "indeterminate for HIV" based on conventional serological and molecular assays. Analytical sensitivity of different molecular and serological assays used in this study may have varied due to HIV-1 viral suppression resulting from antiretroviral therapy (ART). Additional studies are needed to better understand the impact of therapy on HIV diagnosis
Subject(s)
Brazil , Immunoassay , HIV Antibodies , Viral Load , Antiretroviral Therapy, Highly Active , Transgender Persons , Rapid Diagnostic TestsABSTRACT
La presente norma de la OMS, se basa en las directrices de la OMS y en el manual operativo conexo. Los objetivos de la norma son mejorar el acceso a las PDRO y su uso como prueba inicial para las personas con tuberculosis presuntiva detectada mediante búsqueda activa o pasiva de casos, aumentar la detección de casos confirmados bacteriológicamente y de la farmacorresistencia, y reducir el tiempo transcurrido hasta el diagnóstico. La norma consta de 12 parámetros de referencia que deberán calcular los países en los cuatro pasos de la continuidad diagnóstica: detección de un caso de tuberculosis presuntiva, acceso a las pruebas, realización de las pruebas y recepción del diagnóstico