Brown adipose tissue prevents glucose intolerance and cardiac remodeling in high-fat-fed mice after a mild myocardial infarction.

BACKGROUND: Obesity increases the risk of developing impaired glucose tolerance (IGT) and type 2 diabetes (T2D) after myocardial infarction (MI). Brown adipose tissue (BAT) is important to combat obesity and T2D, and increasing BAT mass by transplantation improves glucose metabolism and cardiac function. The objective of this study was to determine if BAT had a protective effect on glucose tolerance and cardiac function in high-fat diet (HFD) fed mice subjected to a mild MI. METHODS: Male C57BL/6 mice were fed a HFD for eight weeks and then divided into Sham (Sham-operated) and +BAT (mice receiving 0.1 g BAT into their visceral cavity). Sixteen weeks post-transplantation, mice were further subdivided into ±MI (Sham; Sham-MI; +BAT; +BAT-MI) and maintained on a HFD. Cardiac (echocardiography) and metabolic function (glucose and insulin tolerance tests, body composition and exercise tolerance) were assessed throughout 22 weeks post-MI. Quantitative PCR (qPCR) was performed to determine the expression of genes related to metabolic function of perigonadal adipose tissue (pgWAT), subcutaneous white adipose tissue (scWAT), liver, heart, tibialis anterior skeletal muscle (TA); and BAT. RESULTS: +BAT prevented the increase in left ventricle mass (LVM) and exercise intolerance in response to MI. Similar to what is observed in humans, Sham-MI mice developed IGT post-MI, but this was negated in +BAT-MI mice. IGT was independent of changes in body composition. Genes involved in inflammation, insulin resistance, and metabolism were significantly altered in pgWAT, scWAT, and liver in Sham-MI mice compared to all other groups. CONCLUSIONS: BAT transplantation prevents IGT, the increase in LVM, and exercise intolerance following MI. MI alters the expression of several metabolic-related genes in WAT and liver in Sham-MI mice, suggesting that these tissues may contribute to the impaired metabolic response. Increasing BAT may be an important intervention to prevent the development of IGT or T2D and cardiac remodeling in obese patients post-MI.

One-anastomosis gastric bypass modulates the serum levels of pro- and anti-inflammatory oxylipins, which may contribute to the resolution of inflammation.

BACKGROUND/OBJECTIVES: Oxylipins are polyunsaturated fatty acid derivatives involved in the regulation of various processes, including chronic inflammation, insulin resistance and hepatic steatosis. They can be synthesized in various tissues, including adipose tissue. There is some evidence that obesity is associated with the deregulation of serum oxylipin levels. The aim of this study was to evaluate the effect of bariatric surgery (one-anastomosis gastric bypass) on the serum levels of selected oxylipins and their fatty acid precursors and to verify the hypothesis that their changes after surgery can contribute to the resolution of inflammation. Moreover, we compared the oxylipin levels (prostaglandin E2, 13-HODE, maresin 1 and resolvin E1), fatty acids and the expression of enzymes that synthesize oxylipins in adipose tissue of lean controls and subjects with severe obesity. SUBJECTS/METHODS: The study included 50 patients with severe obesity that underwent bariatric surgery and 41 subjects in lean, control group. Fatty acid content was analyzed by GC-MS, oxylipin concentrations were measured with immunoenzymatic assay kits and real-time PCR analysis was used to assess mRNA levels in adipose tissue. RESULTS: Our results show increased expression of some enzymes that synthesize oxylipins in adipose tissue and alterations in the levels of oxylipins in both adipose tissue and serum of subjects with obesity. After bariatric surgery, the levels of anti-inflammatory oxylipins increased, whereas pro-inflammatory oxylipins decreased. CONCLUSIONS: In patients with obesity, the metabolism of oxylipins is deregulated in adipose tissue, and their concentrations in serum are altered. Bariatric surgery modulates the serum levels of pro- and anti-inflammatory oxylipins, which may contribute to the resolution of inflammation.

Identification of a novel mutation in thyroxine-binding globulin (TBG) gene associated with TBG-deficiency and its effect on the thyroid function.

PURPOSE: This study presents a case of familial transmission of thyroxine-binding globulin (TBG) deficiency. The SERPINA7-gene which codes for TBG is located on the X-chromosome (Xq21-22). More than 45 mutations have been reported to cause TBG- deficiency from various countries, but none from India so far. Genetic analysis of SERPINA7 gene was carried out to determine the cause of low TBG levels in one family. METHODS: DNA samples of the propositus and the family members were subjected to Polymerase Chain Reaction (PCR) followed by direct sequencing. Allele-specific PCR and Next-gen sequencing (NGS) were employed to confirm the site of the mutation. Thyroid function tests were estimated by Radioimmunoassay (RIA) and Immunoradiometric assay (IRMA) kits. X-chromosomal inactivation status was analyzed in the female members harboring the mutation. RESULTS: A mutational screening in this family revealed a novel frame-shift mutation S353Q, 354fs3X in the exon 4 of the SERPINA7 gene which will be referred to as TBG-complete deficiency-India (TBG-CD-Ind). One out of four female family members harboring the mutation showed selective X-chromosomal inactivation. The affected family members were clinically euthyroid initially, showed changes in the thyroid function when tested after a long time span. However, the changes in the thyroid function in the affected family members had an autoimmune etiology. CONCLUSION: This study presents the first report of TBG-CD from India wherein a novel frameshift mutation referred to as TBG-CD-Ind (S353Q, 354fs3X) in the SERPINA7 gene was detected. No apparent association was identified between thyroid function and the TBG-mutation in the affected subjects. A detailed biochemical and genomic testing to determine the exact cause of discordant TFT in the patients would certainly aid in the unequivocal diagnosis of the thyroid function and for the precise individualized treatment.

Standardization of an organic DNA extraction method from dried blood spots and its downstream molecular applications in neonatal screening and diagnostic confirmation of lysosomal disorders

Introduction: Dried blood spot (DBS) samples have been used for diagnostic purposes since their introduction in the neonatal screening of phenylketonuria almost 50 years ago. The range of its application has been extended to modern approaches, such as next-generation sequencing (NGS) for molecular genetic testing. This study aimed to evaluate the use of a standardized organic method for DNA extraction from DBS samples in the diagnostic setting.Methods: The clinical applicability of the method was tested using 3 samples collected from a newborn screening project for lysosomal storage diseases, allowing the determination of the genotype of the individuals. DNA was extracted from 3 3-mm diameter DBS punches. Quality, purity, and concentration were determined, and method performance was assessed by standard polymerase chain reaction, restriction length polymorphism, Sanger sequencing, and targeted NGS.Results: Results were compared with the ones obtained from DNA samples extracted following the internally validated in-house extraction protocol that used 6 3-mm punches of DBS and samples extracted from whole blood.Conclusion: This organic method proved to be effective in obtaining high-quality DNA from DBS, being compatible with several downstream molecular applications, in addition to having a lower cost per sample

Low Molecular Weight Fucoidan Can Inhibit the Fibrosis of Diabetic Kidneys by Regulating the Kidney Lipid Metabolism.

In this study, a diabetic kidney disease model was established by placing the test rats on a high-sugar/high-fat diet combined with streptozotocin induction. Histopathological examination (H&E, Masson, and PASM stain) showed pathological changes in the diabetic rat kidneys, in addition to fibrotic symptoms and collagen deposition. Immunohistochemistry and western blot analyses indicated that the diabetic condition significantly increased the expressions of fibrotic markers including collagen, α-SMA, and fibronectin. The levels of cholesterol, triglyceride, and low-density lipoprotein were also increased in diabetic kidney disease (DKD) rat blood, while the level of high-density lipoprotein was decreased. The results of Oil red O staining experiments indicated that the kidneys of diabetic rats exhibited appreciable fat deposition, with high contents of triglyceride and cholesterol. To inhibit fibrosis and reduce fat deposition, low molecular weight fucoidan (LMWF) may be used. Based on PCR and western blot analyses, LMWF can regulate the expression levels of important lipid metabolism regulators, thereby impeding the development of kidney fibrosis. Through the vitro model, it also be indicated that LMWF could inhibit fibrosis process through regulating lipid metabolism which induced by palmitic acid.

Diagnostic Accuracy of Immunohistochemistry in Detecting MGMT Methylation Status in Patients with Glioma.

BACKGROUND: The O6-methylguanine-DNA methyltransferase (MGMT) gene prevents mismatch in DNA replication and transcription by repairing mutagenic DNA lesions. MGMT is a predictor biomarker of chemotherapy in high-grade and low-grade gliomas based on high-risk clinical conditions. It also can be used for therapeutic decisions to predict hypermutation in recurrence in newly diagnosed low-grade gliomas. The gold standard  examination for the methylation is Polymerase Chain Reaction (PCR). However, this technique is not widely available in Indonesia for daily practice. Thus, an uncomplicated and simpler method such as immunohistochemistry (IHC) is needed as an alternative examination. This study aimed to predict the diagnostic accuracy of immunohistochemistry (IHC) in detecting the methylation status of O6-methylguanine-DNA methyltransferase (MGMT) in glioma. METHODS: This research was a cross-sectional study using formalin-fixed paraffin embedded (FFPE) tissue samples of glioma patients, dating between October 2017 until March 2021. Diagnosis of glioma was established based on clinical, radiological, and histopathological findings. MGMT methylation status was investigated using the IHC and PCR techniques. Diagnostic value of IHC was analyzed, with PCR as a gold standard method. Optimum threshold to determine positivity of IHC was determined by the Area Under the Curve (AUC) on Receiver Operating Characteristics (ROC) curve and Youden index. RESULTS: Among 75 samples examined, 29 (38.7%) patients were methylated. IHC detected MGMT methylation with sensitivity of 86.2%, specificity of 63.0%, positive predictive value of 59.5%, negative predictive value of 87.9% and accuracy of 72.0%. The AUC was 0.746, indicating moderate diagnostic value. Optimum positivity threshold of the IHC examination based on Youden Index was 10%. CONCLUSION: IHC examination can be used to detect MGMT methylation status of glioma patients in limited resources setting, where PCR technique is not available.

Novel Circulating Hypermethylated RASSF1A ddPCR for Liquid Biopsies in Patients With Pediatric Solid Tumors.

Liquid biopsies can be used to investigate tumor-derived DNA, circulating in the cell-free DNA (cfDNA) pool in blood. We aimed to develop a droplet digital polymerase chain reaction (ddPCR) assay detecting hypermethylation of tumor suppressor gene RASSF1A as a simple standard test to detect various pediatric tumor types in small volume blood samples and to evaluate this test for monitoring treatment response of patients with high-risk neuroblastoma. METHODS: We developed a ddPCR assay to sensitively detect tumor-derived hypermethylated RASSF1A DNA in liquid biopsies. We tested this assay in plasma of 96 patients with neuroblastoma, renal tumors, rhabdomyosarcoma, or Hodgkin lymphoma at diagnosis and in cerebrospinal fluid of four patients with brain tumors. We evaluated the presence of hypermethylated RASSF1A in plasma samples during treatment and follow-up in 47 patients with neuroblastoma treated according to high-risk protocol and correlated results with blood mRNA-based and bone marrow mRNA-based minimal residual disease detection and clinical outcomes. RESULTS: The total cfDNA level was significantly higher in patients with metastatic neuroblastoma and nephroblastoma compared with healthy adult and pediatric controls. Hypermethylated RASSF1A was present in 41 of 42 patients with metastatic neuroblastoma and in all patients with nephroblastoma, with the median percentage of 69% and 21% of total RASSF1A, respectively. Hypermethylated RASSF1A levels decreased during therapy and recurred at relapse. CONCLUSION: Our findings demonstrate the value of ddPCR-based detection of hypermethylated RASSF1A as a circulating molecular tumor marker in neuroblastoma. Our preliminary investigation of RASSF1A hypermethylation detection in circulating cfDNA of other pediatric tumor entities demonstrates potential as a pan-tumor marker, but requires investigation in larger cohorts to evaluate its use and limitations.

Performance evaluation of RDT, light microscopy, and PET-PCR for detecting Plasmodium falciparum malaria infections in the 2018 Zambia National Malaria Indicator Survey.

BACKGROUND: Zambia continues to advance on the path to elimination with significant reductions in malaria morbidity and mortality. Crucial components that have contributed to progress thus far and are necessary for achieving the national malaria elimination goals include properly identifying and treating all malaria cases through accurate diagnosis. This study sought to compare and assess the diagnostic performance of Rapid Diagnostic Tests (RDT) and Light Microscopy (LM) with photo-induced electron transfer polymerase chain reaction (PET-PCR) as the gold standard using 2018 Malaria Indicator Survey (MIS) data across Zambia to better understand diagnostic accuracy metrics and how these vary across a transmission gradient. METHODS: Cross-sectional samples collected in a nationally representative survey from 7 provinces in Zambia were tested for the presence of malaria parasites by light microscopy (LM), rapid diagnostic test (RDT) and the gold standard PET-PCR. Diagnostic performance was assessed including sensitivity, specificity, negative- and positive-predictive values across a wide malaria transmission spectrum. Diagnostic accuracy metrics were measured, and statistically significant differences were calculated between test methods for different outcome variables. RESULTS: From the individuals included in the MIS, the overall prevalence of Plasmodium falciparum malaria was 32.9% by RDT, 19.4% by LM, and 23.2% by PET-PCR. Herein, RDT and LM diagnostic performance was compared against gold standard PET-PCR with LM displaying a higher diagnostic accuracy than RDTs (91.3% vs. 84.6% respectively) across the transmission spectrum in Zambia. However, the performance of both diagnostics was significantly reduced in low parasitaemia samples. Consistent with previous studies, RDT diagnostic accuracy was predominantly affected by a high rate of false positives. CONCLUSIONS: RDTs and LM both perform well across a range of transmission intensities within their respective target applications, i.e., in the community, for the former, where ease of use and speed of result is critical, and at the health facility, for the latter, where accuracy is prioritized. However, the performance of both diagnostic methods is adversely affected by low parasitaemia infections. As Zambia moves towards elimination more sensitive tools may be required to identify the last cases.

Performance of rapid diagnostic tests, microscopy, loop-mediated isothermal amplification (LAMP) and PCR for malaria diagnosis in Ethiopia: a systematic review and meta-analysis.

BACKGROUND: Rapid accurate diagnosis followed by effective treatment is very important for malaria control. Light microscopy remains the "golden standard" method for malaria diagnosis. Diagnostic test method must have sufficient level of accuracy for detecting malaria parasites. Therefore, this study aimed to investigate the diagnostic accuracy of rapid diagnostic tests (RDTs), microscopy, loop-mediated isothermal amplification (LAMP) and/or polymerase chain reaction (PCR) for the malaria diagnosis in Ethiopia. METHODS: Data bases such as PubMed, PubMed central, Science direct databases, Google scholar, and Scopus were searched from September to October, 2020 for studies assessing the diagnostic accuracy of RDTs, microscopy, LAMP and PCR methods for malaria diagnosis. RESULTS: A total of 29 studies published between 2001 and 2020 were analysed using review manager, Midas (Stata) and Meta-disc. The sensitivity and specificity of studies comparing RDT with microscopy varies from 79%-100% to 80%-100%, respectively. The sensitivity of LAMP (731 tests) was 100% and its specificity was varies from 85 to 99% when compared with microscopy and PCR. Considerable heterogeneity was observed between studies included in this meta-analysis. Meta-regression showed that blinding status and target antigens were the major sources of heterogeneity (P < 0.05). RDT had an excellent diagnostic accuracy (Area under the ROC Curve = 0.99) when compared with microscopy. Its specificity was quite good (93%-100%) except for one outlier (28%), but lower "sensitivity" was observed when PCR is a reference test. This indicates RDT had a good diagnostic accuracy (AUC = 0.83). Microscopy showed a very good diagnostic accuracy when compared with PCR. CONCLUSIONS: The present study showed that microscopy and RDTs had high efficiency for diagnosing febrile malaria patients. The diagnostic accuracy of RDT was excellent when compared with microscopy. This indicates RDTs have acceptable sensitivities and specificities to be used in resource poor settings as an alternative for microscopy. In this study, LAMP showed an excellent sensitivities and specificities. Furthermore, the need of minimum equipment and relatively short time for obtaining results can made LAMP one of the best alternatives especially for accurate diagnosis of asymptomatic malaria.

Prenatal prediction of fetal Rh C, c and E status by amplification of maternal cfDNA and deep sequencing.

BACKGROUND: The Rh blood group system has considerable clinical importance. The C, c, and E antigens are targets of alloantibodies. Anti-C, anti-c or anti-E alloreactive antibodies produced in pregnant women can cause anemia of a fetus carrying the corresponding antigens. AIMS: Based on NGS technology, we have developed a noninvasive diagnostic assay to predict the fetal blood group of C, c or E antigens by sequencing cell-free DNA (cfDNA) during pregnancy. MATERIALS AND METHODS: The SNVs underlying either the C, c or E antigens were PCR amplified and sequenced using NGS on a MiSeq instrument. The DNA sequences encoding the C, c or E antigen were counted, as were the number of total sequences. Based on the percentage of fetally derived target SNVs inherited from the father, the fetal blood group could be predicted. RESULTS: The results of 55 consecutive RHCE prenatal analyses with postnatal serological blood group determination of 30 newborns showed no discordant results. A threshold discerning positive from negative samples was set at 0.05% specific reads. DISCUSSION: Noninvasive, prenatal prediction of fetal blood groups by sequencing cfDNA for the detection of low-level RHCE*C, RHCE*c and RHCE*E sequences was established as an accurate and robust assay applicable for use in clinical settings.

Associations between obesity-related gene expression in maternal and cord blood and newborn adiposity: findings from the Araraquara Cohort study.

BACKGROUND/OBJECTIVES: Genes involved in the regulation of metabolism, adipose tissue deposition, inflammation, and the appetite-satiety axis may play an important role in fetal development, and possibly induce permanent metabolic changes and fat accumulation. In this study we investigated: (1) obesity-related gene expression in maternal and cord blood of overweight/obese and normal-weight pregnant women; (2) associations between obesity-related gene expression in maternal and cord blood; and (3) associations of gene expression in each of maternal and cord blood with newborn adiposity. SUBJECTS/METHODS: Twenty-five overweight/obese and 32 normal-weight pregnant women were selected from the Araraquara Cohort Study according to their pre-pregnancy BMI. Maternal and cord blood gene expression of LEPR, STAT3, PPARG, TLR4, IL-6, IL-10, FTO, MC4R, TNF-α, and NFκB were investigated by relative real-time PCR quantification. The body composition of the newborns was assessed by air displacement plethysmography. Associations between maternal and cord blood gene expression and markers of newborn adiposity (weight, BMI, and fat mass%) were explored by linear regression models controlling for maternal age, pre-pregnancy BMI, maternal gestational weight gain, gestational age, and newborn sex. RESULTS: There was higher TLR4, NFκB, and TNF-a expression, and lower IL-6 expression, in overweight/obese pregnant women and their respective newborns compared with normal-weight women and their newborns (p < 0.001). Maternal PPARG gene expression was associated with both weight and fat mass % of the newborns, and cord blood IL-10 expression was associated with BMI and fat mass %, controlling for confounders. CONCLUSION: To our knowledge, this is the first study to evaluate the relationship of maternal and cord blood gene expression with adiposity markers of the newborn. Our results provide evidence for the contribution of maternal and cord blood gene expression-particularly maternal PPARG and TLR4 expression, and cord blood IL-10 expression-to newborn weight, BMI, and fat mass %.

Quantification of the Tradeoff between Test Sensitivity and Test Frequency in a COVID-19 Epidemic-A Multi-Scale Modeling Approach.

Control strategies that employ real time polymerase chain reaction (RT-PCR) tests for the diagnosis and surveillance of COVID-19 epidemic are inefficient in fighting the epidemic due to high cost, delays in obtaining results, and the need of specialized personnel and equipment for laboratory processing. Cheaper and faster alternatives, such as antigen and paper-strip tests, have been proposed. They return results rapidly, but have lower sensitivity thresholds for detecting virus. To quantify the effects of the tradeoffs between sensitivity, cost, testing frequency, and delay in test return on the overall course of an outbreak, we built a multi-scale immuno-epidemiological model that connects the virus profile of infected individuals with transmission and testing at the population level. We investigated various randomized testing strategies and found that, for fixed testing capacity, lower sensitivity tests with shorter return delays slightly flatten the daily incidence curve and delay the time to the peak daily incidence. However, compared with RT-PCR testing, they do not always reduce the cumulative case count at half a year into the outbreak. When testing frequency is increased to account for the lower cost of less sensitive tests, we observe a large reduction in cumulative case counts, from 55.4% to as low as 1.22% half a year into the outbreak. The improvement is preserved even when the testing budget is reduced by one half or one third. Our results predict that surveillance testing that employs low-sensitivity tests at high frequency is an effective tool for epidemic control.

What is the yield of malaria reactive case detection in the Greater Mekong Sub-region? A review of published data and meta-analysis.

BACKGROUND: Reactive malaria case detection involves the screening of those in contact with index cases and is used in countries in the Greater Mekong Sub-region. The yield of reactive case detection, defined here as the percentage of positive malaria cases among potential contacts who were screened, was assessed. METHODS: A literature search was conducted on PubMed to identify studies on reactive case detection in the Greater Mekong Sub-region. Eligible published articles were reviewed and pooled estimates from the studies were calculated, by type of malaria test used. RESULTS: Eighty-five publications were retrieved, of which 8 (9.4%) eligible articles were included in the analysis. The yield from reactive case detection ranged from 0.1 to 4.2%, with higher rates from PCR testing compared with microscopy and/or rapid diagnostic test. The overall yield from microscopy and/or rapid diagnostic test was 0.56% (95% CI 0.31-0.88%), while that from PCR was 2.35% (95% CI 1.19-3.87%). The two studies comparing different target groups showed higher yield from co-workers/co-travellers, compared with household contacts. CONCLUSION: In low malaria transmission settings, the effectiveness of reactive case detection is diminishing. In the Greater Mekong Sub-region, modifying reactive case detection from household contacts to co-workers/co-travellers and from testing to presumptive treatment of targeted contacts, could increase the impact of this approach.

A comparison on the percentage of polymerase chain reaction positivity for SARS-CoV-2 between Public Health Center referrals and direct walk-in patients: A single center retrospective analysis in Tokyo.

INTRODUCTION: The Public Health Center (PHC)-known as hokenjo in Japan-assume a crucial role in disease control. Coronavirus disease 2019 (COVID-19) is one of many designated infectious diseases monitored by the agency. During the present pandemic, patients who suspected COVID-19 were instructed to call the Coronavirus Consultation Center in the PHC prior to visiting the hospital. The aim of this study was to elucidate the differences in polymerase chain reaction (PCR) positivity between PHC referrals and direct walk-in patients. METHODS: The present was a single-center, retrospective cohort study conducted at the Tokyo Metropolitan Hospital from March to September, 2020. Patients who received a PCR test for SARS-CoV-2 were included and categorized into the PHC referral or direct walk-in groups. The outcomes included the total number of patients undergoing PCR tests and the percentage of PCR positivity in each group. RESULTS: We identified 1680 patients (781 PHC referred and 899 direct walk-in groups). The percentage of PCR positivity did not significantly differ between the PHC referral and direct walk-in groups during the first wave (30.5% vs. 29.2%; p = 0.78). PCR positivity was significantly higher in the PHC referral group than the direct walk-in group during the second wave (30.1% vs. 23.1%; p = 0.051) and entire study period (30.2% vs. 24.7%; p = 0.011). CONCLUSIONS: Despite health authority recommendations, the number of direct walk-in patients were higher than PHC referral patients. The percentage of PCR positivity was significantly higher in the PHC referral group than in the direct walk-in group.

Performance and Diagnostic Accuracy of Human Papillomavirus Testing on Self-Collected Urine and Vaginal Samples in a Referral Population.

PURPOSE: The study aimed to evaluate the diagnostic accuracy of polymerase chain reaction ‒based high-risk human papillomavirus (HPV) assays on self-collected vaginal and urine samples for detection of precancerous cervical lesions in referral population. MATERIALS AND METHODS: Women referred for colposcopy following abnormal cytology, were included this study. A total of 314 matched urine, vaginal, and cervical samples were collected. All samples were tested for HPV DNA using the RealTime HR-S HPV and Anyplex II HPV 28 assays. Primary endpoints were sensitivity for cervical intraepithelial neoplasia (CIN) 2+/CIN3+ and specificity for

ART Initiation for Infants Diagnosed With HIV Through Point of Care and Conventional Polymerase Chain Reaction Testing in Kenya: A Case Series.

We sought to understand the sequence of testing and treatment among nine infants offered both conventional and point-of-care testing and diagnosed as HIV-positive by 6 months of age in Kenya. One infant received per protocol testing and treatment. Patient-level (late presentation and disengagement), provider-level (reluctance and error/oversight) and system-level (stock outs, errors) challenges delayed diagnosis and treatment. Early point-of-care testing can streamline testing; however, challenges mitigate benefits.

Initial SARS-CoV-2 PCR crossing point does not predict hospitalization and duration of PCR positivity.

This study aimed to determine if the crossing point of the initial positive SARS-CoV-2 PCR test correlated with patient demographics, subsequent hospitalization, or duration of positivity. Seventy-three patients with two or more positive PCR tests had a median time of 23 days to two consecutive negative results.

Increased Intensity Of PCR Testing Reduced COVID-19 Transmission Within Countries During The First Pandemic Wave.

Experts agree that reverse transcription-polymerase chain reaction (PCR) testing is critical in controlling coronavirus disease 2019 (COVID-19), but decision makers disagree on how much testing is optimal. Controlling for interventions and ecological factors, we used linear regression to quantify testing's impact on COVID-19's average reproduction number, which represents transmissibility, in 173 countries and territories (which account for 99 percent of the world's COVID-19 cases) during March-June 2020. Among interventions, PCR testing had the greatest influence: a tenfold increase in the ratio of tests to new cases reported reduced the average reproduction number by 9 percent across a range of testing levels. Our results imply that mobility reductions (for example, shelter-in-place orders) were less effective in developing countries than in developed countries. Our results help explain how some nations achieved near-elimination of COVID-19 and the failure of lockdowns to slow COVID-19 in others. Our findings suggest that the testing benchmarks used by the World Health Organization and other entities are insufficient for COVID-19 control. Increased testing and isolation may represent the most effective, least costly alternative in terms of money, economic growth, and human life for controlling COVID-19.

Evidence-based diagnostic algorithm for visceral leishmaniasis in Bangladesh.

Evidence-based diagnostic algorithm is highly recommended for the visceral leishmaniasis (VL). This cross-sectional study was performed in Bangladesh to evaluate VL diagnostic tools including serology, buffy coat smear microscopy for LD body and various DNA-based techniques using buffy coat in 100 confirmed VL cases and 100 controls. The performance of tools against spleen smear (gold standard) was evaluated using kappa coefficient. Diagnostic precision and other inherent indicators were considered for index scoring (IS) of performance of tools using factor analysis. A diagnostic algorithm was formulated based on the IS and availability of the tools at different health care facilities of Bangladesh. A high level of agreement (kappa ≥  0.80) was observed for all the diagnostic tools. The highest kappa coefficients were found for rK39 RDT and rK39 ELISA (0.95), followed by ssuRNA-PCR (0.94), Buffy coat smear (0.93), rK28 ELISA (0.92), rK28 RDT (0.89), LAMP (0.89), Mini-exon PCR (0.86), ITS1 (0.85), and ITS2 PCR (0.80). rK39 RDT was found to be the best diagnostic test (IS: 1.7) followed by rK28 RDT (IS: 1.5), buffy coat smear microscopy (IS: 0.5), rK39 & rK28 ELISA (IS: 0.3), ssuRNA-PCR (IS: -0.7) and LAMP, Mini-exon, ITS1, & ITS2 PCR (IS: -0.9). rK39 RDT has been proposed as the best option for primary health care facilities, while buffy coat smear microscopy was found to be a good adjunct for confirmation of serology-positive cases and proposed for secondary and tertiary facilities. ssuRNA-PCR or LAMP can be an alternate confirmation tool only applicable to the tertiary facilities.

Radiografía de tórax pediátrica en la era COVID / Pediatric chest X-rays during the COVID-19 pandemic

INTRODUCCIÓN: A mediados de diciembre de 2019 se describió en China una enfermedad infecciosa causada por un nuevo tipo de coronavirus que provocaba infección respiratoria aguda y pronto se extendió por el país y por el resto del mundo. A pesar de que la radiografía de tórax es la prueba de elección inicial ante infecciones respiratorias bajas con o sin disnea, hay pocos artículos que describan los hallazgos radiológicos del niño con COVID-19. OBJETIVO: Describir las características clínicas, analíticas y los hallazgos en la radiografía de tórax de la población pediátrica atendida con clínica de infección respiratoria en nuestro hospital durante el mes de marzo. Analizar la frecuencia de COVID-19 frente a otras infecciones respiratorias y sus manifestaciones radiológicas. MATERIAL Y MÉTODOS: Estudio observacional transversal desde el 1 de marzo al 31 de marzo del 2020 de todos los niños con clínica de infección respiratoria (fiebre, rinorrea, tos y/o disnea) que han precisado radiografía de tórax en nuestro hospital. RESULTADOS: 231 niños precisaron radiografía de tórax por clínica de infección respiratoria, 90 (38,9%) niñas y 141 (61%) niños; rango de edad 1 mes-16 años, con una mediana de 4 años. La mayoría de los niños presentaron síntomas leves (88,4%). Un 29,9% de los niños presentaba ambiente epidémico familiar positivo con clínica respiratoria similar a la que presentaba el paciente. Se realizó test PCR SARS-CoV-2 a 47 de los niños que acudieron a la urgencia (20,3%), que fue positivo en 3 (6,3% de los testados). Se realizaron determinaciones microbiológicas al 36,8% (85/231), demostraron otros agentes infecciosos diferentes al SARS-CoV-2 en el 35,3% de los pacientes (30/85). Únicamente uno de los pacientes PCR positivo para SARS-CoV-2 presentó infección de orina por Escherichia coli y hemocultivo positivo para Streptococcus viridans. El 73,2% de los pacientes presentó algún tipo de alteración en la radiografía de tórax. Los engrosamientos peribronquiales fueron el hallazgo más común en el 57%. El 38,5% presentó consolidación parenquimatosa, que en un 29,2% fue bilateral y en un 3,3% asoció derrame pleural. Se demostró aumento de la trama intersticial en el 7,3%. El 7,3% se manifestó con opacidades en vidrio deslustrado. CONCLUSIÓN: Durante el mes de marzo coexistieron infecciones respiratorias sintomáticas COVID-19 y no COVID-19. El patrón radiológico de las infecciones respiratorias, incluida la COVID-19, no es específico y la radiografía en ningún caso fue suficiente para establecer el diagnóstico. Los niños con clínica respiratoria compatible con COVID-19, con o sin PCR confirmatoria, presentaron síntomas leves y en su mayoría no requirieron ingreso ni ventilación invasiva. En un entorno de transmisión comunitaria, la ausencia de antecedente epidemiológico conocido no debería ser una contraindicación para realizar estudio de PCR para SARS-CoV-2

BACKGROUND: An infectious disease caused by a new type of coronavirus that can manifest as an acute respiratory infection was discovered in China in mid-December 2019 and soon spread throughout the country and to the rest of the world. Although chest X-rays are the initial imaging technique of choice for low respiratory infections with or without dyspnea, few articles have reported the radiologic findings in children with COVID-19. OBJECTIVE: To describe the clinical, laboratory, and chest X-ray findings in pediatric patients with signs and symptoms of respiratory infection attended at our hospital in March 2020. To analyze the frequency of COVID-19 compared to other respiratory infections, and to describe the radiologic manifestations of COVID-19 in pediatric patients. MATERIAL AND METHODS: This cross-sectional observational study included all children with clinical manifestations of respiratory infection (fever, rhinorrhea, cough, and/or dyspnea) that required chest X-rays in our hospital between March 1 and March 31. RESULTS: A total of 231 pediatric patients (90 (39%) girls and 141 (61%) boys; mean age, 4 y, range 1 month - 16 years) underwent chest X-rays for suspected respiratory infections. Most (88.4%) had mild symptoms; 29.9% had a family member positive for COVID-19 with symptoms similar to those of the patient. Nasal and/or throat swabs were analyzed for SARS-CoV-2 with PCR in the 47 (20.3%) children who presented at the emergency department; 3 (6.3%) of these were positive. Microbiological analyses were done in 85 (36.8%) of all patients, finding infections due to pathogens other than SARS-CoV-2 in 30 (35.3%). One of the patients with a PCR positive for SARS-CoV-2 had urine infection due to E. coli and blood culture positive for S. viridans. Abnormalities were observed on X-rays in 73.2% of the patients. Peribronchial thickening was the most common abnormal finding, observed in 57% of patients. Parenchymal consolidations were observed in 38.5%, being bilateral in 29.2% and associated with pleural effusion in 3.3%. The interstitial lines were thickened in 7.3%, and 7.3% had ground-glass opacities. CONCLUSION: During March 2020, COVID-19 and other symptomatic respiratory infections were observed. The radiologic pattern of these infections is nonspecific, and chest X-rays alone are insufficient for the diagnosis. Children with clinical manifestations compatible with COVID-19 (with or without PCR confirmation of infection by SARS-CoV-2) had mild symptoms and most did not require admission or invasive mechanical ventilation. In a context of community transmission, the absence of a known epidemiological antecedent should not be a contraindication for PCR to detect SARS-CoV-2