Use of the Ishii Test for screening sarcopenia in older adults: a systematic review with meta-analysis of diagnostic test accuracy (DTA) studies.

BACKGROUND: The Ishii Test is recommended by the European Working Group on Sarcopenia in Older People (EWGSOP2), however the use of this technique is still little explored in the clinical context and the scientific literature. OBJECTIVE: We aimed to verify the use of the Test of Ishii in screening for sarcopenia in older adults. METHODS: We searched three electronic databases and two reviewers independently screened and assessed the studies. Studies with older adults (60 years or more) of both genders, no year or language restriction and which aimed to evaluate sarcopenia using the Ishii Test and another diagnostic criteria were selected. A summary of the ROC curve, sensitivity and specificity were performed using the MedCalc and SPSS software programs, respectively. RESULTS: A total of 3,298 references were identified in the database, 278 by manually searching, and finally 11 studies were included for the review. The screening test showed good sensitivity and specificity in both genders. All studies showed values above the considered value for the Area Under the Curve (AUC) results, without discriminating power (0.500). Four studies used the original values, and five studies developed a new cut-off point. A summary of the AUC curve showed the diamond close to one, indicating that the Ishii test has good performance for screening sarcopenia (I2=83,66%; p<0.001; 95%CI: 69.38 to 91.28 for men; and I2=60.04%; p<0.001; 95%CI: 13.06 to 81.63 for women). CONCLUSION: The Ishii Test can be considered a useful tool for the early identification of sarcopenia in older adults. However, further studies are still needed to understand the behavior of this screening tool. TRIAL REGISTRATION: CRD42023424392.

Systematic review and meta-analysis: assessing the accuracy of rapid immunochromatographic tests in dengue diagnosis.

The objective of this systematic review is to analyze the diagnostic accuracy of rapid dengue diagnostic tests. The search was conducted in the following databases: LILACS, Medline (Pubmed), CRD, The Cochrane Library, Trip Medical Database and Google Scholar. ELISA and PCR assays were adopted as reference methods. Thirty-four articles were included in this systematic review. Receiver operating characteristic (ROC) and Forest Plot were performed to evaluate sensitivity and specificity for each parameter analyzed (NS1, IgM and IgG). The results revealed that the combined analysis of the IgM antibody with the NS1 antigen resulted in greater sensitivity than the isolated analysis of IgM. The three analytes together showed the best performance, with a combined sensitivity of 90 % (95 % CI: 89-92 %) using ELISA as a comparator. Thus, the present review provides relevant knowledge for decision-making between the available rapid diagnostic tests.

Diagnosis of human brucellosis: Systematic review and meta-analysis.

BACKGROUND: Brucellosis, a widely spread zoonotic disease, poses significant diagnostic challenges due to its non-specific symptoms and underreporting. Timely and accurate diagnosis is crucial for effective patient management and public health control. However, a comprehensive comparative review of available diagnostic tests is lacking. METHODOLOGY/PRINCIPAL FINDINGS: This systematic review addressed the following question: 'What is the accuracy of the available tests to confirm human brucellosis?' Two independent reviewers examined articles published up to January 2023. The review included original studies reporting symptomatic patients with brucellosis suspicion, through any index test, with sensitivity and/or specificity as outcomes. As exclusion criteria were considered: sample size smaller than 10 patients, studies focusing on complicated brucellosis, and those lacking essential information about index or comparator tests. Sensitivity and specificity were assessed, with consideration for the index test, and 'culture' and 'culture and standard tube agglutination test (SAT)' were used as reference standards. Bias assessment and certainty of evidence were carried out using the QUADAS-2 and GRADE tools, respectively. A total of 38 studies reporting diagnostic test performance for human brucellosis were included. However, the evidence available is limited, and significant variability was observed among studies. Regarding the reference test, culture and/or SAT are deemed more appropriate than culture alone. Rose Bengal, IgG/IgM ELISA, and PCR exhibited equally high performances, indicating superior overall diagnostic accuracy, with very low certainty of the evidence. CONCLUSIONS/SIGNIFICANCE: This systematic review underscores the potential of the Rose Bengal test, IgG/IgM ELISA, and PCR as promising diagnostic tools for brucellosis. However, the successful implementation and recommendations for their use should consider the local context and available resources. The findings highlight the pressing need for standardization, improved reporting, and ongoing advancements in test development to enhance the accuracy and accessibility of brucellosis diagnosis.

A systematic review and meta-analysis on the accuracy of rapid immunochromatographic tests for dengue diagnosis.

Rapid immunochromatographic tests are frequently used to diagnose dengue due to their easy use, low cost, and fast response. A high level of accuracy is essential for rapid diagnostic tests to support their large-scale use. Thus, this systematic review aims to evaluate the accuracy of rapid dengue diagnostic tests. The investigation was run through the following databases: LILACS, Medline (Pubmed), CRD, The Cochrane Library, Trip Medical Database, and Google Scholar. To solve difficulties, two independent reviewers performed document screening and selection. ELISA assay was adopted as a reference test because of several methodologic advantages. Seventeen articles were included accordingly, reckoning 6837 participating individuals. The receiver operating characteristic (ROC) and Forest Plot were conducted to evaluate the sensitivity and specificity for each analyzed parameter (anti-dengue IgM, IgG, and NS1 antigen). The risk of bias and quality of evidence were assessed as moderate using QUADAS-2 and Grading of Recommendations Assessment, Development, and Evaluation (GRADE), respectively. The sensitivity of IgM concerning the studied tests ranged from 13.8 to 90%, while that of NS1 ranged from 14.7 to 100% (95% CI). The antibodies with NS1 presented increased sensitivity; pooled data show that the association of the three analytes bestows the best result, with a combined sensitivity of 90% (CI 95%: 87-92%) and a pooled specificity of 89% (CI 95%: 87-92%). Thus, the present review provides relevant knowledge for decision-making between available rapid diagnostic tests.

In Situ Nanocoating on Porous Pyrolyzed Paper Enables Antibiofouling and Sensitive Electrochemical Analyses in Biological Fluids.

Electrochemical detection in complex biofluids is a long-standing challenge as electrode biofouling hampers its sensing performance and commercial translation. To overcome this drawback, pyrolyzed paper as porous electrode coupled with the drop casting of an off-the-shelf polysorbate, that is, Tween 20 (T20), is described here by taking advantage of the in situ formation of a hydrophilic nanocoating (2 nm layer of T20). The latter prevents biofouling while providing the capillarity of samples through paper pores, leveraging redox reactions across both only partially fouled and fresh electrodic surfaces with increasing detection areas. The nanometric thickness of this blocking layer is also essential by not significantly impairing the electron-transfer kinetics. These phenomena behave synergistically to enhance the sensibility that further increases over long-term exposures (4 h) in biological fluids. While the state-of-the-art antibiofouling strategies compromise the sensibility, this approach leads to peak currents that are up to 12.5-fold higher than the original currents after 1 h exposure to unprocessed human plasma. Label-free impedimetric immunoassays through modular bioconjugation by directly anchoring spike protein on gold nanoparticles are also allowed, as demonstrated for the COVID-19 screening of patient sera. The scalability and simplicity of the platform combined with its unique ability to operate in biofluids with enhanced sensibility provide the generation of promising biosensing technologies toward real-world applications in point-of-care diagnostics, mass testing, and in-home monitoring of chronic diseases.

Genomic surveillance of SARS-CoV-2 Spike gene by sanger sequencing.

The SARS-CoV-2 responsible for the ongoing COVID pandemic reveals particular evolutionary dynamics and an extensive polymorphism, mainly in Spike gene. Monitoring the S gene mutations is crucial for successful controlling measures and detecting variants that can evade vaccine immunity. Even after the costs reduction resulting from the pandemic, the new generation sequencing methodologies remain unavailable to a large number of scientific groups. Therefore, to support the urgent surveillance of SARS-CoV-2 S gene, this work describes a new feasible protocol for complete nucleotide sequencing of the S gene using the Sanger technique. Such a methodology could be easily adopted by any laboratory with experience in sequencing, adding to effective surveillance of SARS-CoV-2 spreading and evolution.

Nested pool testing strategy for the diagnosis of infectious diseases.

The progress of the SARS-CoV-2 pandemic requires the design of large-scale, cost-effective testing programs. Pooling samples provides a solution if the tests are sensitive enough. In this regard, the use of the gold standard, RT-qPCR, raises some concerns. Recently, droplet digital PCR (ddPCR) was shown to be 10-100 times more sensitive than RT-qPCR, making it more suitable for pooling. Furthermore, ddPCR quantifies the RNA content directly, a feature that, as we show, can be used to identify nonviable samples in pools. Cost-effective strategies require the definition of efficient deconvolution and re-testing procedures. In this paper we analyze the practical implementation of an efficient hierarchical pooling strategy for which we have recently derived the optimal, determining the best ways to proceed when there are impediments for the use of the absolute optimum or when multiple pools are tested simultaneously and there are restrictions on the throughput time. We also show how the ddPCR RNA quantification and the nested nature of the strategy can be combined to perform self-consistency tests for a better identification of infected individuals and nonviable samples. The studies are useful to those considering pool testing for the identification of infected individuals.

Papel de la ecografía en la sala de emergencia en el diagnóstico del trauma de tórax / The Role of Sonography in the Emergency Room for the Diagnosis of Thoracic Trauma

Introducción: Dentro de la atención al lesionado con trauma torácico se cuenta con varios medios diagnósticos, entre ellos la evaluación por ecografía focalizada en trauma extendido a tórax, el cual ha mostrado una alta sensibilidad, aun realizado por médicos no radiólogos como cirujanos generales, emergencistas e intensivistas. Objetivo: Determinar la utilidad de la ecografía torácica extendida realizada por cirujanos en lesionados con traumatismo torácico. Métodos: Se realizó un estudio observacional, descriptivo de evaluación de pruebas diagnósticas con un diseño transversal, en 1052 pacientes ingresados en la sala de emergencia. Se les realizó la evaluación por ecografía torácica extendida en el Hospital Universitario "General Calixto García", durante el período comprendido entre enero de 2020 y febrero de 2021. Resultados: Fueron realizados en un periodo de 1 año un total de 1052 ultrasonidos torácicos, 221 casos fueron positivos, de ellos 81 neumotórax (7,7 por ciento) y 62 hemoneumotórax (5,9 por ciento) todos confirmados por tomografía de tórax. La edad promedio fue de 45,27 (18-97), el sexo masculino prevaleció con 772 casos (73,4 por ciento). Los mecanismos productores de trauma más frecuentes fueron: caída de altura 273 casos (26 por ciento) y trauma contuso 181 casos (17,2 por ciento). La ecografía torácica extendida obtuvo una sensibilidad de un 95,24 por ciento y una especificidad de 99,88 por ciento en el diagnóstico lesiones torácicas. Conclusiones: La ecografía torácica extendida demostró que en manos de los cirujanos generales es una herramienta confiable, segura, no invasiva, poco costosa, repetible, que permite diagnosticar rápidamente lesiones torácicas y tratarlas(AU)

Introduction: Within care for the injured patient with thoracic trauma there are several diagnostic means. For example, extended focused assessment with sonography for thoracic trauma has shown high sensitivity, even when performed by non-radiologists such as general surgeons, emergency specialists and intensivists. Objective: To determine the usefulness of extended thoracic sonography performed by surgeons on injured patients with thoracic trauma. Methods: An observational, descriptive and cross-sectional study of diagnostic tests assessment was carried out in 1052 patients admitted to the emergency room. They were assessed by extended thoracic sonography at General Calixto García University Hospital, during the period between January 2020 and February 2021. Results: A total of 1052 thoracic ultrasounds were performed in a period of one year, of which 221 cases were positive. Of them, 81 were pneumothorax (7.7 percent) and 62 were hemopneumothorax (5.9 percent), all confirmed by chest tomography. The average age was 45.27 (18-97). The male sex prevailed, with 772 cases (73.4 percent). The most frequent trauma-producing mechanisms were altitude fall, accounting for 273 cases (26 percent), and blunt trauma, accounting for 181 cases (17.2 percent). Extended thoracic ultrasound showed a sensitivity of 95.24 percent and a specificity of 99.88 percent in the diagnosis of thoracic injuries. Conclusions: Extended thoracic ultrasound showed that, in the hands of general surgeons, it is a reliable, safe, noninvasive, inexpensive and repeatable tool that allows rapid diagnosis and treatment of thoracic injuries(AU)

Laboratory Findings in Patients with Probable Dengue Diagnosis from an Endemic Area in Colombia in 2018.

As demonstrated with the novel coronavirus pandemic, rapid and accurate diagnosis is key to determine the clinical characteristic of a disease and to improve vaccine development. Once the infected person is identified, hematological findings may be used to predict disease outcome and offer the correct treatment. Rapid and accurate diagnosis and clinical parameters are pivotal to track infections during clinical trials and set protection status. This is also applicable for re-emerging diseases like dengue fever, which causes outbreaks in Asia and Latin America every 4 to 5 years. Some areas in the US are also endemic for the transmission of dengue virus (DENV), the causal agent of dengue fever. However, significant number of DENV infections in rural areas are diagnosed solely by clinical and hematological findings because of the lack of availability of ELISA or PCR-based tests or the infrastructure to implement them in the near future. Rapid diagnostic tests (RDT) are a less sensitive, yet they represent a timely way of detecting DENV infections. The purpose of this study was to determine whether there is an association between hematological findings and the probability for an NS1-based DENV RDT to detect the DENV NS1 antigen. We also aimed to describe the hematological parameters that are associated with the diagnosis through each test.

Emergent canine visceral leishmaniasis in Argentina: Comparative diagnostics and relevance to proliferation of human disease.

BACKGROUND: Visceral leishmaniasis (VL) is a zoonotic protozoal vector-borne disease that is a major public health challenge. In Argentina, canine (CVL) and human visceral leishmaniasis (HVL) have recently emerged. There is a lack of standardised diagnostic tests for CVL, which hinders control of CVL and HVL. METHODOLOGY/PRINCIPAL FINDINGS: Sampling was carried out in Puerto Iguazú, Argentina, comprising 190 asymptomatic, oligosymptomatic and polysymptomatic dogs. The following diagnostics were applied: microscopy of lymph node aspirate (LNA); three immunochromatographic rapid diagnostic tests (RDTs), prototype rK28-ICT, rK39-ICT (both Coris BioConcept), commercial rK39 (InBios); ELISA for IgG, IgG1 and IgG2, against rK28, rK39 or crude lysate antigen. DNA detection and analysis, with 30 dogs, was of the ITS1 region using skin samples, and loop-mediated isothermal amplification (LAMP; Eiken Loopamp) of buffy coat, skin scrape or LNA. 15.4% of dogs were positive by LNA microscopy. The rK28 RDT had higher seropositivity rate (61%) than either a prototype rK39 RDT (31.4%) or commercial rK39 RDT (18.8%), without cross-reactivity with six other pathogens. IgG anti-rK39 ELISA antibody titres, but not IgG2, were positively correlated with number of clinical signs. LAMP with LNA had a higher positivity rate than PCR; buffy coat sampling was more sensitive than skin scrape. ITS1 confirmed Leishmania (Leishmania) infantum as the agent of CVL. Leishmania (Viannia) spp. was detected in skin samples from two dogs, compatible with Leishmania (Viannia) braziliensis. CONCLUSIONS/SIGNIFICANCE: Seroprevalence confirmed rapid increase in CVL in Puerto Iguazú. The rK28 RDT test potentially has great value for improved point-of-care diagnosis. Given cost reduction and accessibility, commercial LAMP may be applicable to buffy coat. RDT biomarkers of CVL clinical status are required to combat spread of CVL and HVL. The presence of Viannia, perhaps as an agent of human mucocutaneous leishmaniasis (MCL), highlights the need for vigilance and surveillance.

Sensitivity and Specificity of two rapid tests for the diagnosis of infection by Trypanosoma cruzi in a Colombian population.

OBJECTIVE: To evaluate diagnostic precision of two rapid diagnostic tests (RDT's) on patients with chronic Chagas disease. METHODOLOGY: Prospective study with the following inclusion criteria: subjects older than 3 years, signed informed consent. Exclusion criterion: subjects could not have previously received treatment for infection with T. cruzi. The study population were participants in a screening process undertaken in rural and urban zones of the department Boyacá, Colombia. Two RDT's were performed to all participants: the Chagas Detect Plus InBios (CDP) and the Chagas Stat-Pak (CSP) and as a reference standard the ELISA Chagas III GrupoBios and the Chagas ELISA IgG+IgM I Vircell tests were used. In the case of discordant results between the two ELISA tests, an indirect immunofluorescence was done. RESULTS: Three hundred-five (305) subjects were included in the study (38 patients with leishmaniasis), of which 215 tested negative for T cruzi and 90 tested positive according to the reference standard. The sensitivity of the RDT's were 100% (CI 95% 95.9-100), and the specificity of the CDP was 99.1% (CI 95% 96.6-99.8) and for CSP was 100% (CI 95% 98.3-100). The agreement of CDP was 99.5% and for CSP was 100% with Kappa values of (k = 99.1; CI 95% 92.6-99.8%) and (k = 100; CI 95% 94.3-100), respectively. RDT's did not present cross-reactions with samples from patients who were positive for leishmaniasis. CONCLUSIONS: The findings demonstrate excellent results from the RDT's in terms of validity, safety, and reproducibility. The results obtained provide evidence for the recommendation for using these tests in a Colombian epidemiological context principally in endemic areas in which laboratory installations necessary to perform conventional tests are not available, or they are scarce and to help in diagnosing chronic Chagas disease in order to provide access to treatment as soon as possible.

Herramientas digitales como un aliado informativo en el Perú para el autocuidado en tiempos de COVID-19 / Digital tools as information aids for self-care in the time of COVID-19 in Peru

Este estudio tuvo como objetivo analizar las métricas disponibles de las herramientas digitales que fomentan el autocuidado para comprender sus efectos en la población en tiempos de COVID-19. Se realizó una búsqueda sobre sitios web, aplicaciones móviles y redes sociales que ofrecían información a la población sobre la COVID-19, los cuales debían pertenecer al gobierno peruano o a instituciones oficiales relacionadas con la salud. Se revisaron las métricas disponibles de cada herramienta digital para una posterior evaluación de uso. Los sitios web identificados brindaban información referente a la COVID-19, así como datos actualizados sobre los casos existentes, la autoevaluación para descartar la enfermedad y el reporte de resultados de la prueba para su diagnóstico. El sitio web más visitado fue el del Gobierno del Perú, el cual contenía la página web del Ministerio de Salud. Asimismo, la aplicación móvil del Gobierno del Perú PerúEnTusManos fue la más descargada por parte de la población peruana. Las redes sociales, en colaboración con estas herramientas digitales en el Perú, vienen siendo utilizadas activamente para informar e interactuar con la población en estos tiempos de COVID-19. Por lo tanto, por la rápida adaptabilidad que tienen los sitios web y las aplicaciones móviles, estas se han convertido en el Perú en una herramienta informativa ideal para hacer frente a la pandemia de la COVID-19(AU)

The purpose of the study was to analyze the metrics available for digital tools fostering self-care to understand their effects on the population in the time of COVID-19. A search was conducted about websites, mobile applications and social networks offering information to the population about COVID-19 and belonging to the Peruvian government or health-related official institutions. A review was performed of the metrics available for each digital tool with a view to an eventual evaluation of their use. The websites identified provided information about COVID-19 as well as updated data about existing cases, self-evaluation to rule out the disease and the report of results of diagnostic tests. The most visited website was that of the Government of Peru, which contained the website of the Ministry of Health. The mobile application of the Government of Peru PerúEnTusManos was the most commonly downloaded by the Peruvian population. Social networks, in joint cooperation with these digital tools, are actively used in Peru to inform and interact with the population in the time of COVID-19. Due to the rapid adaptability of websites and mobile applications, these have become an ideal information tool in Peru to face the COVID-19 pandemic(AU)

Field Performance of a Rapid Diagnostic Test for the Serodiagnosis of Abdominal Cystic Echinococcosis in the Peruvian Highlands.

We evaluated the performance of a commercial rapid diagnostic test (RDT) in a field setting for the diagnosis of abdominal cystic echinococcosis (CE) using sera collected during an ultrasound population screening in a highly endemic region of the Peruvian Andes. Abdominal CE was investigated by ultrasonography. Sera collected from individuals with abdominal CE (cases) and age- and gender-matched volunteers with no abdominal CE (controls) were tested independently in two laboratories (Peru and Italy) using the VIRapid® HYDATIDOSIS RDT and RIDASCREEN® Echinococcus IgG enzyme-linked immunosorbent assay. Performance indexes of single and serially combined tests were calculated and applied to hypothetical screening and clinical scenarios. Test concordance was also evaluated. Prevalence of abdominal CE was 6.00% (33 of 546) by ultrasound. Serum was obtained from 33 cases and 81 controls. The VIRapid test showed similar sensitivity (76% versus 74%) and lower specificity (79% versus 96%) than results obtained in a hospital setting. RDTs showed better performance when excluding subjects reporting surgery for CE and if weak bands were considered negative. Concordance between tests was moderate to very good. In hypothetical screening scenarios, ultrasound alone or confirmed by RDTs provided more reliable prevalence figures than serology alone, which overestimated it by 5 to 20 times. In a simulation of case diagnosis with pre-test probability of CE of 50%, positive and negative post-test probabilities of the VIRapid test were 78% and 22%, respectively. The application of the VIRapid test alone would not be reliable for the assessment of population prevalence of CE, but could help clinical decision making in resource-limited settings.

Comparison of four extraction methods for the detection of hepatitis B virus DNA in dried blood spot samples.

The dried blood spot (DBS) samples are a useful resource for viral DNA isolation and important in increasing access to HBV diagnosis. However, the choice of the DNA extraction method is crucial for reliable results. We compared the reliability of four DNA extraction methods using DBS samples for the qualitative and quantitative detection of HBV. A panel of serially diluted HBV DNA in whole blood was spotted onto filter paper (Whatman 903 paper and Whatman FTA cards). Four methods were used to extract DNA: QIAamp® DNA Blood Mini Kit (Qiagen); High Pure Viral Nucleic Acid Kit (Roche); Invisorb Spin Blood Midi Kit (Invitek), and DBS Genomic DNA Isolation Kit (Norgen Biotek). Two qualitative PCRs for the core and surface gene regions of HBV were used, and in-house real-time PCR was also evaluated. It was possible to detect HBV DNA using all extraction and PCR protocols. The lowest limit of detection was found using Whatman 903 paper, Roche extraction, and qualitative PCR (20 copies of HBV DNA per ml) for the surface/polymerase HBV region. In the case of in-house real-time PCR, the lowest limit of detection was found using both Roche and Qiagen assays (estimated 2 × 103 copies per ml). These results suggest the importance of both the extraction method and PCR protocol in detecting HBV DNA in DBS. This study provides insights into the utility of DBS samples in HBV molecular diagnosis and their feasibility in low resource areas where cold storage and transportation may be difficult.

Potential for community based surveillance of febrile diseases: Feasibility of self-administered rapid diagnostic tests in Iquitos, Peru and Phnom Penh, Cambodia.

Rapid diagnostic tests (RDTs) have the potential to identify infectious diseases quickly, minimize disease transmission, and could complement and improve surveillance and control of infectious and vector-borne diseases during outbreaks. The U.S. Defense Threat Reduction Agency's Joint Science and Technology Office (DTRA-JSTO) program set out to develop novel point-of-need RDTs for infectious diseases and deploy them for home use with no training. The aim of this formative study was to address two questions: 1) could community members in Iquitos, Peru and Phnom Penh, Cambodia competently use RDTs of different levels of complexity at home with visually based instructions provided, and 2) if an RDT were provided at no cost, would it be used at home if family members displayed febrile symptoms? Test kits with written and video (Peru only) instructions were provided to community members (Peru [n = 202]; Cambodia [n = 50]) or community health workers (Cambodia [n = 45]), and trained observers evaluated the competency level for each of the several steps required to successfully operate one of two multiplex RDTs on themselves or other consenting participant (i.e., family member). In Iquitos, >80% of residents were able to perform 11/12 steps and 7/15 steps for the two- and five-pathogen test, respectively. Competency in Phnom Penh never reached 80% for any of the 12 or 15 steps for either test; the percentage of participants able to perform a step ranged from 26-76% and 23-72%, for the two- and five-pathogen tests, respectively. Commercially available NS1 dengue rapid tests were distributed, at no cost, to households with confirmed exposure to dengue or Zika virus; of 14 febrile cases reported, six used the provided RDT. Our findings support the need for further implementation research on the appropriate level of instructions or training needed for diverse devices in different settings, as well as how to best integrate RDTs into existing local public health and disease surveillance programs at a large scale.

Examination of respiratory specimens improves microbiological diagnosis of patients with presumptive extrapulmonary tuberculosis.

OBJECTIVES: Bacteriological confirmation of extrapulmonary tuberculosis (EPTB) is challenging for several reasons: the paucibacillary nature of the sample; scarce resources, mainly in middle and low-income countries; the need for hospitalization; and unfavorable outcomes. We evaluated the diagnostic role of respiratory specimen examination prospectively in a cohort of patients with presumptive EPTB. METHODS: From July 2018 to January 2019, in a tuberculosis (TB)/HIV reference hospital, a cohort of 157 patients with presumed EPTB was evaluated. Xpert® MTB/RIF Ultra or a culture-positive result was considered for bacteriologically confirmed TB. RESULTS: Out of 157 patients with presumptive EPTB, 97 (62%) provided extrapulmonary and respiratory specimens and 60 (38%) extrapulmonary specimens only. Of the 60 patients with extrapulmonary samples, 5 (8%) were positive. Of those with respiratory and extrapulmonary samples, 27 (28%) were positive: 10 in both the respiratory and extrapulmonary samples, 6 in the extrapulmonary sample only, and 11 in the respiratory sample only. A respiratory specimen examination increased by 6-fold the chance of bacteriological confirmation of TB (odds ratio = 5.97 [1.11-47.17]). CONCLUSION: We conclude that respiratory samples should be examined in patients with presumptive EPTB.

A faster and less costly alternative for RNA extraction of SARS-CoV-2 using proteinase k treatment followed by thermal shock.

One of the biggest challenges during the pandemic has been obtaining and maintaining critical material to conduct the increasing demand for molecular tests. Sometimes, the lack of suppliers and the global shortage of these reagents, a consequence of the high demand, make it difficult to detect and diagnose patients with suspected SARS-CoV-2 infection, negatively impacting the control of virus spread. Many alternatives have enabled the continuous processing of samples and have presented a decrease in time and cost. These measures thus allow broad testing of the population and should be ideal for controlling the disease. In this sense, we compared the SARS-CoV-2 molecular detection effectiveness by Real time RT-PCR using two different protocols for RNA extraction. The experiments were conducted in the National Institute of Health (INS) from Peru. We compared Ct values average (experimental triplicate) results from two different targets, a viral and internal control. All samples were extracted in parallel using a commercial kit and our alternative protocol-samples submitted to proteinase K treatment (3 µg/µL, 56°C for 10 minutes) followed by thermal shock (98°C for 5 minutes followed by 4°C for 2 minutes); the agreement between results was 100% in the samples tested. In addition, we compared the COVID-19 positivity between six epidemiological weeks: the initial two in that the Real time RT-PCR reactions were conducted using RNA extracted by commercial kit, followed by two other using RNA obtained by our kit-free method, and the last two using kit once again; they did not differ significantly. We concluded that our in-house method is an easy, fast, and cost-effective alternative method for extracting RNA and conducing molecular diagnosis of COVID-19.

Development and Evaluation of a Three-Dimensional Printer-Based DNA Extraction Method Coupled to Loop Mediated Isothermal Amplification for Point-of-Care Diagnosis of Congenital Chagas Disease in Endemic Regions.

Vertical transmission of Trypanosomacruzi is the cause of congenital Chagas disease, a re-emerging infectious disease that affects endemic and nonendemic regions alike. An early diagnosis is crucial because prompt treatment achieves a high cure rate, precluding evolution to symptomatic chronic Chagas disease. However, early diagnosis involves low-sensitive parasitologic assays, making necessary serologic confirmation after 9 months of life. With the aim of implementing early diagnostic strategies suitable for minimally equipped laboratories, a T. cruzi-loop-mediated isothermal amplification (LAMP) prototype was coupled with an automated DNA-extraction device repurposed from a three-dimensional printer (PrintrLab). The whole process takes <3 hours to yield a result, with an analytical sensitivity of 0.1 to 2 parasite equivalents per milliliter, depending on the T. cruzi strain. Twenty-five blood samples from neonates born to seropositive mothers were tested blindly. In comparison to quantitative real-time PCR, the PrintrLab-LAMP dual strategy showed high agreement, while both molecular-based methodologies yielded optimal sensitivity and specificity with respect to microscopy-based diagnosis of congenital Chagas disease. PrintrLab-LAMP detected all 10 congenitally transmitted T. cruzi infections, showing promise for point-of-care early diagnosis of congenital Chagas disease.