iMAGING: a novel automated system for malaria diagnosis by using artificial intelligence tools and a universal low-cost robotized microscope.

Introduction: Malaria is one of the most prevalent infectious diseases in sub-Saharan Africa, with 247 million cases reported worldwide in 2021 according to the World Health Organization. Optical microscopy remains the gold standard technique for malaria diagnosis, however, it requires expertise, is time-consuming and difficult to reproduce. Therefore, new diagnostic techniques based on digital image analysis using artificial intelligence tools can improve diagnosis and help automate it. Methods: In this study, a dataset of 2571 labeled thick blood smear images were created. YOLOv5x, Faster R-CNN, SSD, and RetinaNet object detection neural networks were trained on the same dataset to evaluate their performance in Plasmodium parasite detection. Attention modules were applied and compared with YOLOv5x results. To automate the entire diagnostic process, a prototype of 3D-printed pieces was designed for the robotization of conventional optical microscopy, capable of auto-focusing the sample and tracking the entire slide. Results: Comparative analysis yielded a performance for YOLOv5x on a test set of 92.10% precision, 93.50% recall, 92.79% F-score, and 94.40% mAP0.5 for leukocyte, early and mature Plasmodium trophozoites overall detection. F-score values of each category were 99.0% for leukocytes, 88.6% for early trophozoites and 87.3% for mature trophozoites detection. Attention modules performance show non-significant statistical differences when compared to YOLOv5x original trained model. The predictive models were integrated into a smartphone-computer application for the purpose of image-based diagnostics in the laboratory. The system can perform a fully automated diagnosis by the auto-focus and X-Y movements of the robotized microscope, the CNN models trained for digital image analysis, and the smartphone device. The new prototype would determine whether a Giemsa-stained thick blood smear sample is positive/negative for Plasmodium infection and its parasite levels. The whole system was integrated into the iMAGING smartphone application. Conclusion: The coalescence of the fully-automated system via auto-focus and slide movements and the autonomous detection of Plasmodium parasites in digital images with a smartphone software and AI algorithms confers the prototype the optimal features to join the global effort against malaria, neglected tropical diseases and other infectious diseases.

Advances and challenges in automated malaria diagnosis using digital microscopy imaging with artificial intelligence tools: A review.

Malaria is an infectious disease caused by parasites of the genus Plasmodium spp. It is transmitted to humans by the bite of an infected female Anopheles mosquito. It is the most common disease in resource-poor settings, with 241 million malaria cases reported in 2020 according to the World Health Organization. Optical microscopy examination of blood smears is the gold standard technique for malaria diagnosis; however, it is a time-consuming method and a well-trained microscopist is needed to perform the microbiological diagnosis. New techniques based on digital imaging analysis by deep learning and artificial intelligence methods are a challenging alternative tool for the diagnosis of infectious diseases. In particular, systems based on Convolutional Neural Networks for image detection of the malaria parasites emulate the microscopy visualization of an expert. Microscope automation provides a fast and low-cost diagnosis, requiring less supervision. Smartphones are a suitable option for microscopic diagnosis, allowing image capture and software identification of parasites. In addition, image analysis techniques could be a fast and optimal solution for the diagnosis of malaria, tuberculosis, or Neglected Tropical Diseases in endemic areas with low resources. The implementation of automated diagnosis by using smartphone applications and new digital imaging technologies in low-income areas is a challenge to achieve. Moreover, automating the movement of the microscope slide and image autofocusing of the samples by hardware implementation would systemize the procedure. These new diagnostic tools would join the global effort to fight against pandemic malaria and other infectious and poverty-related diseases.

Soluble angiotensin-converting enzyme 2 as a prognostic biomarker for disease progression in patients infected with SARS-CoV-2

BackgroundThere is a need for better prediction of disease severity in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Soluble angiotensin-converting enzyme 2 (sACE2) arises from shedding of membrane ACE2 (mACE2) that is known to be a receptor for the spike protein of SARS-CoV-2; however, its value as a biomarker for disease severity is unknown. This study evaluated the predictive value of sACE2 in the context of other known biomarkers of inflammation and tissue damage (C-reactive protein [CRP], growth/differentiation factor-15 [GDF-15], interleukin-6 [IL-6], and soluble fms-like tyrosine kinase-1 [sFlt-1]) in patients with and without SARS-CoV-2 with different clinical outcomes. MethodsFor univariate analyses, median differences between biomarker levels were calculated for the following patient groups classified according to clinical outcome: reverse transcription polymerase chain reaction (RT-PCR)-confirmed SARS-CoV-2 positive (Groups 1-4); RT-PCR-confirmed SARS-CoV-2 negative following previous SARS-CoV-2 infection (Groups 5 and 6); and RT-PCR-confirmed SARS-CoV-2 negative controls (Group 7). ResultsMedian levels of CRP, GDF-15, IL-6, and sFlt-1 were significantly higher in patients with SARS-CoV-2 who were admitted to hospital compared with patients who were discharged (all p<0.001), whereas levels of sACE2 were significantly lower (p<0.001). Receiver operating characteristic curve analysis of sACE2 provided cut-offs for the prediction of hospital admission of [≤]0.05 ng/mL (positive predictive value: 89.1%) and [≥]0.42 ng/mL (negative predictive value: 84.0%). ConclusionThese findings support further investigation of sACE2, either as a single biomarker or as part of a panel, to predict hospitalisation risk and disease severity in patients infected with SARS-CoV-2. HIGHLIGHTSNoelia Diaz Troyano: Noy-Lee-ah Dee-az Tro-yah-no Better prediction of disease severity in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is needed. We measured soluble angiotensin-converting enzyme 2 (soluble ACE2) and other biomarkers of inflammation and tissue damage in patients recruited from Vall dHebron University Hospital, with and without SARS-CoV-2 and with different clinical outcomes. Levels of soluble ACE2 were significantly lower in patients with SARS-CoV-2 who had the most severe clinical outcome in all comparisons. These findings support a protective role for soluble ACE2 in SARS-CoV-2 infection and warrant further investigation of soluble ACE2 as a biomarker for disease severity in patients with SARS-CoV-2.

New susceptibility loci for severe COVID-19 by detailed GWAS analysis in European populations

Given the highly variable clinical phenotype of Coronavirus disease 2019 (COVID-19), a deeper analysis of the host genetic contribution to severe COVID-19 is important to improve our understanding of underlying disease mechanisms. Here, we describe an extended GWAS meta-analysis of a well-characterized cohort of 3,260 COVID-19 patients with respiratory failure and 12,483 population controls from Italy, Spain, Norway and Germany/Austria, including stratified analyses based on age, sex and disease severity, as well as targeted analyses of chromosome Y haplotypes, the human leukocyte antigen (HLA) region and the SARS-CoV-2 peptidome. By inversion imputation, we traced a reported association at 17q21.31 to a highly pleiotropic [~]0.9-Mb inversion polymorphism and characterized the potential effects of the inversion in detail. Our data, together with the 5th release of summary statistics from the COVID-19 Host Genetics Initiative, also identified a new locus at 19q13.33, including NAPSA, a gene which is expressed primarily in alveolar cells responsible for gas exchange in the lung.

T-cell responses as a correlate of COVID-19 vaccination. A pilot study in Health Care Workers.

BackgroundIt is crucial to assess the levels of protection generated by natural infection or SARS-CoV-2 vaccines, mainly in individuals professionally exposed and in vulnerable groups. Measuring T-cell responses may complement antibody tests currently in use as correlates of protection. Our aim was to assess the feasibility of a validated assay of T-cell responses. MethodsTwenty health-care-workers (HCW) were included. Antibody test to SARS-CoV-2 N and S-proteins in parallel with a commercially available whole-blood-interferon-gamma-release-assay (IGRA) to S-peptides and two detection methods, CLIA and ELISA were determined. ResultsIGRA test detected T-cell responses in naturally exposed and vaccinated HCW already after first vaccination dose. The correlation by the two detection methods was very high (R>0.8) and sensitivity and specificity ranged between 100 and 86% and 100-73% respectively. Even though there was a very high concordance between specific antibody levels and the IGRA assay in the ability to detect immune response to SARS-CoV-2, there was a relatively low quantitative correlation. In the small group primed by natural infection, one vaccine dose was sufficient to reach immune response plateau. IGRA was positive in one, with Ig(S) antibody negative vaccinated immunosuppressed HCW illustrating another advantage of the IGRA-test. ConclusionWhole-blood-IGRA-tests amenable to automation and constitutes a promising additional tool for measuring the state of the immune response to SARS-CoV-2; they are applicable to large number of samples and may become a valuable correlate of protection to COVID-19, particularly for vulnerable groups at risk of being re-exposed to infection, as are health-care-workers.

The ABO blood group locus and a chromosome 3 gene cluster associate with SARS-CoV-2 respiratory failure in an Italian-Spanish genome-wide association analysis

BackgroundRespiratory failure is a key feature of severe Covid-19 and a critical driver of mortality, but for reasons poorly defined affects less than 10% of SARS-CoV-2 infected patients. MethodsWe included 1,980 patients with Covid-19 respiratory failure at seven centers in the Italian and Spanish epicenters of the SARS-CoV-2 pandemic in Europe (Milan, Monza, Madrid, San Sebastian and Barcelona) for a genome-wide association analysis. After quality control and exclusion of population outliers, 835 patients and 1,255 population-derived controls from Italy, and 775 patients and 950 controls from Spain were included in the final analysis. In total we analyzed 8,582,968 single-nucleotide polymorphisms (SNPs) and conducted a meta-analysis of both case-control panels. ResultsWe detected cross-replicating associations with rs11385942 at chromosome 3p21.31 and rs657152 at 9q34, which were genome-wide significant (P<5x10-8) in the meta-analysis of both study panels, odds ratio [OR], 1.77; 95% confidence interval [CI], 1.48 to 2.11; P=1.14x10-10 and OR 1.32 (95% CI, 1.20 to 1.47; P=4.95x10-8), respectively. Among six genes at 3p21.31, SLC6A20 encodes a known interaction partner with angiotensin converting enzyme 2 (ACE2). The association signal at 9q34 was located at the ABO blood group locus and a blood-group-specific analysis showed higher risk for A-positive individuals (OR=1.45, 95% CI, 1.20 to 1.75, P=1.48x10-4) and a protective effect for blood group O (OR=0.65, 95% CI, 0.53 to 0.79, P=1.06x10-5). ConclusionsWe herein report the first robust genetic susceptibility loci for the development of respiratory failure in Covid-19. Identified variants may help guide targeted exploration of severe Covid-19 pathophysiology.

Naturally occurring SARS-CoV-2 gene deletions close to the spike S1/S2 cleavage site in the viral quasispecies of COVID19 patients

The SARS-CoV-2 spike (S) protein, the viral mediator for binding and entry into the host cell, has sparked great interest as a target for vaccine development and treatments with neutralizing antibodies. Initial data suggest that the virus has low mutation rates, but its large genome could facilitate recombination, insertions, and deletions, as has been described in other coronaviruses. Here, we deep-sequenced the complete SARS-CoV-2 S gene from 18 patients (10 with mild and 8 with severe COVID-19), and found that the virus accumulates deletions upstream and very close to the S1/S2 cleavage site, generating a frameshift with appearance of a stop codon. These deletions were found in a small percentage of the viral quasispecies (2.2%) in samples from all the mild and only half the severe COVID-19 patients. Our results suggest that the virus may generate free S1 protein released to the circulation. We propose that natural selection has favored a "Dont burn down the house" strategy, in which free S1 protein may compete with viral particles for the ACE2 receptor, thus reducing the severity of the infection and tissue damage without losing transmission capability.

First Enterovirus D68 (EV-D68) cases detected in hospitalised patients in a tertiary care university hospital in Spain, October 2014 / Primeras detecciones de Enterovirus D68 (EV-D68) en población hospitalizada en España, Octubre 2014

Several outbreaks of Enterovirus 68 (EV-D68) have recently been reported in the USA and Canada, causing substantial hospitalisation of children with severe respiratory disease. The acute flaccid paralysis detected in the USA and Canada among children with EV-D68 infection has raised concerns about the aetiological role of this EV serotype in severe neurological disease. The circulation of EV-D68 in the general European population seems to be low, but European Centre for Disease Prevention and Control (ECDC) recommends being vigilant to new cases, particularly in severely ill hospitalised patients. In October 2014, enteroviruses were detected in respiratory samples collected from five hospitalised patients, children and adults. Phylogenetic analysis of partial VP1 sequences confirmed that the detected enteroviruses belonged to the D68 serotype, which were also similar to strains reported in USA (2014). However, all five patients developed respiratory symptoms, but only one required ICU admission. None of the patients described had symptoms of neurological disease. Other considerations related to the detection methods used for the diagnosis of respiratory enteroviruses are also discussed. In conclusion, additional evidence has been provided that supports the role of EV-D68 in respiratory infections in hospitalised patients

En EEUU y Canadá, desde el pasado verano, se han descrito varios brotes causados por EV-D68 afectando a pacientes, principalmente niños, con enfermedad respiratoria grave. En algunos de estos casos la infección por EV-D68 se ha asociado a enfermedad neurológica grave. Aunque en población europea la circulación de este serotipo parece ser baja, el ECDC recuerda la necesidad de reforzar la vigilancia, especialmente en pacientes hospitalizados. En octubre de 2014, en las muestras respiratorias de 5 pacientes ingresados en el Hospital Universitario Vall d’Hebron de Barcelona, se pudieron detectar enterovirus. Estos fueron caracterizados como EV-D68 mediante análisis filogenético de las secuencias parciales codificantes para la proteína viral VP1. Estas secuencias eran además similares a las de las cepas aisladas en los últimos meses en EEUU. Estos 5 pacientes presentaron síntomas respiratorios, pero sólo uno requirió ingreso en la Unidad de Cuidados Intensivos. Sin embargo, ninguno de los pacientes presentó síntomas de enfermedad neurológica. En este trabajo se comentan también consideraciones relacionadas con los métodos de diagnóstico para enterovirus, especialmente para este serotipo. En conclusión, en este trabajo se confirma el posible papel etiológico del EV-D68 en la infección respiratoria del paciente ingresado

[Microbiological diagnosis of viral respiratory infections in the adult patient]. / Diagnóstico microbiológico de las infecciones virales respiratorias en el paciente adulto.

Conventional techniques for the diagnosis of respiratory viruses are still being used, although molecular methods are now considered as a gold standard in this field. Molecular techniques have a great number of advantages such as an excellent sensitivity, specificity, adaptability to emerging viruses, capability for multiplex and for automation. With all the available repertoire of techniques for microbiological diagnosis, the knowledge relative to respiratory viruses is growing up not only for new aetiological agents but also for its epidemiology. The advances in molecular and non-molecular fast diagnostic methods for one or more respiratory viruses allow quick decisions in the management of the patient. However, there are also disadvantages. The great sensitivity of molecular techniques has meant a significant increase in the rate of multiple detections of respiratory viruses, whose clinical involvement is difficult to interpret. Finally, it remains to show whether the use of new techniques, of high cost, in the microbiological routine diagnosis of acute respiratory viral infections in the hospitalized patient, is cost effective.

Antiviral activity of maca (Lepidium meyenii) against human influenza virus

OBJECTIVE@#To investigate antiviral activity of maca to reduce viral load in Madin-Darby canine kidney (MDCK) cells infected with influenza type A and B viruses (Flu-A and Flu-B, respectively).@*METHODS@#Maca were extracted with methanol (1:2, v/v). The cell viability and toxicity of the extracts were evaluated on MDCK cells using method MTT assay. Antiviral activity of compounds against Flu-A and Flu-B viruses was assayed using a test for determining the inhibition of the cytopathic effect on cell culture and multiplex RT-PCR.@*RESULTS@#The methanol extract of maca showed low cytotoxicity and inhibited influenza-induced cytopathic effect significantly, while viral load was reduced via inhibition of viral growth in MDCK infected cells. Maca contains potent inhibitors of Flu-A and Flu-B with a selectivity index [cytotoxic concentration 50%/IC50] of 157.4 and 110.5, respectively.@*CONCLUSIONS@#In vitro assays demonstrated that maca has antiviral activity not only against Flu-A (like most antiviral agents) but also Flu-B viruses, providing remarkable therapeutic benefits.

Antiviral activity of maca (Lepidium meyenii) against human influenza virus

Objective: To investigate antiviral activity of maca to reduce viral load in Madin-Darby canine kidney (MDCK) cells infected with influenza type A and B viruses (Flu-A and Flu-B, respectively). Methods: Maca were extracted with methanol (1:2, v/v). The cell viability and toxicity of the extracts were evaluated on MDCK cells using method MTT assay. Antiviral activity of compounds against Flu-A and Flu-B viruses was assayed using a test for determining the inhibition of the cytopathic effect on cell culture and multiplex RT-PCR. Results: The methanol extract of maca showed low cytotoxicity and inhibited influenza-induced cytopathic effect significantly, while viral load was reduced via inhibition of viral growth in MDCK infected cells. Maca contains potent inhibitors of Flu-A and Flu-B with a selectivity index [cytotoxic concentration 50%/IC