The prevalence of long COVID-19 syndrome in hospitalized patients with COVID-19 pneumonia.

Introduction: Long COVID affects millions of individuals worldwide with a wide range of persistent symptoms. Pathogenesis, prevalence and clinical approach of this syndrome remain not well characterized.The aim of the study is the estimation of prevalence of long-COVID and identification of possible risk factors. Patients and Methods: This is an observational prospective study including COVID-19 patients hospitalized at the Department of Infectious Diseases of the University General Hospital of Alexandroupolis (Greece). Eligible COVID-19 patients were interviewed and examined 6, 12 and 18 months after COVID-19 symptoms onset and hospital discharge in order to evaluate the prevalence and consequences of long-COVID symptoms. Results: A total number of 995 patients were included. The median age at discharge was 55 years and 53% of patients were retired. The majority was males (57%). Vaccination against SARS-CoV-2 was completed in 52% (n=517) COVID-19 patients. More than 40% of COVID-19 patients had at least one symptom at 18 months after hospitalization. Intravenous antiviral 0treatment with remdesivir and complete vaccination status were found to lead to lower rates of Long-COVID. Conclusions: More studies in larger patient cohorts are needed in order to identify the underlying biological mechanisms of long-COVID and create effective interventions for prevention and treatment.

Recurrent Cryptococcal Meningitis in a Late Presenter of HIV: A Rare Case Report and Review of Literature.

BACKGROUND The highly active antiretroviral treatment (HAART) and the primary prophylaxis in newly diagnosed people living with HIV (PLHIV) have reduced the incidence of opportunistic infections such as cryptococcal meningitis (CM). Relapse of CM is associated with increased morbidity and mortality. The aim of the present case presentation is to report the clinical progress relapse of CM in a man who was a late presenter PLHIV, 1 year after ART initiation with increased CD4 cell count, undetectable viral load, and excellent compliance after disruption of secondary antifungal prophylaxis. CASE REPORT One year after initial diagnosis of HIV and CM, the patient had no neurological or other symptoms, and viral suppression and increased CD4 cell count were achieved. After the completion of 12 months of secondary prophylaxis with fluconazole, an episode of partial seizure with secondary generalization occurred, followed by a short-term memory loss. Magnetic resonance imaging (MRI) indicated a focal lesion in right frontal-parietal brain region. Lumbar puncture was conducted and Cryptococcus neoformans non-resistant to fluconazole was isolated. He received antiepileptic treatment, induction antifungal treatment with liposomal amphotericin and fluconazole, consolidation treatment with fluconazole, and secondary prophylaxis with fluconazole, as in the first episode of CM. One year after the relapse, antiepileptic treatment and secondary prophylaxis with fluconazole continues and no new episode has been reported. The diagnosis of immune reconstitution inflammatory syndrome (IRIS)-related relapse of CM cannot be excluded. CONCLUSIONS Further studies are needed for the evaluation of parameters such as duration of secondary prophylaxis and treatment options for induction and consolidation therapy to reduce the relapse rate of CM.

Ιnterleukin-17A-Enriched Neutrophil Extracellular Traps Promote Immunofibrotic Aspects of Childhood Asthma Exacerbation.

Childhood asthma is a chronic inflammatory airway disorder that can drive tissue remodeling. Neutrophils are amongst the most prominent inflammatory cells contributing to disease manifestations and may exert a potent role in the progression of inflammation to fibrosis. However, their role in asthma exacerbation is still understudied. Here, we investigate the association between neutrophil extracellular traps (NETs) and lung fibroblasts in childhood asthma pathophysiology using serum samples from pediatric patients during asthma exacerbation. Cell-based assays and NETs/human fetal lung fibroblast co-cultures were deployed. Increased levels of NETs and interleukin (IL)-17A were detected in the sera of children during asthma exacerbation. The in vitro stimulation of control neutrophils using the sera from pediatric patients during asthma exacerbation resulted in IL-17A-enriched NET formation. The subsequent co-incubation of lung fibroblasts with in vitro-generated IL-17A-enriched NETs led fibroblasts to acquire a pre-fibrotic phenotype, as assessed via enhanced CCN2 expression, migratory/healing capacity, and collagen release. These data uncover the important pathogenic role of the NET/IL-17A axis in asthma exacerbation, linking lung inflammation to fibroblast dysfunction and fibrosis.

Coronary Artery Ectasia as an Autoimmune Disease Paradigm in a Cross-Sectional Case-Control Study.

Coronary artery ectasia (CAE) is defined as local or generalized aneurysmal dilatation of the coronary arteries. CAE likely represents an exaggerated form of excessive vascular wall remodeling in different clinical settings such as atherosclerosis, vasculitides, connective tissue disorders, hereditary collagen defects, bacterial infections, and congenital malformations. In the present case-control study, we investigated whether the incidental finding of CAE in patients who undergo coronary angiography is associated with presence of autoimmune reactivity. From 2019 to 2022, we identified all consecutive patients with CAE (n = 319) on elective or emergency coronary angiography (n = 7,458). We furthermore included 90 patients with nonectatic coronary arteries as a control group. Antinuclear antibody (ANA) titer was measured in both groups using the indirect immunofluorescence method from peripheral blood samples. The prevalence of CAE in our study cohort was 4.3%. Among patients with CAE (n = 319), presence of positive Antinuclear antibody (ANA) titer was identified in 128 patients (40%). Only 18 patients (20%) from the control group had positive ANA titer. There was a statistically significant greater percentage of patients with positive ANA titer among patients with CAE than among controls (chi-square = 12.39; p <0.001), with an odds ratio of 2.68. Among patients with CAE, there is an increased prevalence of positive ANA titer, suggesting an underlying autoimmune disease. Screening for autoimmune reactivity could be a reasonable diagnostic strategy in patients who undergo coronary angiography with an incidental finding of coronary ectasia because the number needed to screen for positive ANA titer in this subgroup of patients is only 5.

Decreased Levels of Soluble Developmental Endothelial Locus-1 Are Associated with Thrombotic Microangiopathy in Pregnancy.

HELLP (Hemolysis, Elevated Liver enzymes and Low Platelets) syndrome is a life-threatening complication of pregnancy, which is often secondary to preeclampsia. To date, there is no biomarker in clinical use for the early stratification of women with preeclampsia who are under increased risk of HELLP syndrome. Herein, we show that the levels of circulating developmental endothelial locus-1 (DEL-1), which is an extracellular immunomodulatory protein, are decreased in patients with HELLP syndrome compared to preeclampsia. DEL-1 levels are also negatively correlated with the circulating levels of kidney injury molecule-1 (KIM-1), which is a biomarker for disorders associated with kidney damage. Receiver-operating characteristic curve analysis for DEL-1 levels and the DEL-1 to KIM-1 ratio demonstrates that these values could be used as a potential biomarker that distinguishes patients with HELLP syndrome and preeclampsia. Finally, we show that placental endothelial cells are a source for DEL-1, and that the expression of this protein in placenta from patients with HELLP syndrome is minimal. Taken together, this study shows that DEL-1 is downregulated in HELLP syndrome both in the circulation and at the affected placental tissue, suggesting a potential role for this protein as a biomarker, which must be further evaluated.

The Impact of the COVID-19 Pandemic on Antimicrobial Resistance and Management of Bloodstream Infections.

INTRODUCTION: The pressure of the COVID-19 pandemic on healthcare systems led to limited roles of infectious diseases services, increased rates of irrational use of antimicrobials, and incidence of infections by multidrug-resistant microorganisms. The aim of the present study is to evaluate the incidence of antimicrobial resistance and the management of bloodstream infections before and during the COVID-19 pandemic at the University General Hospital of Alexandroupolis (Greece). MATERIALS AND METHODS: This is a retrospective study conducted from January 2018 to December 2022. Data were collected from the University Microbiology Laboratory per semester regarding the isolated strains of Gram-positive and -negative bacteria in blood cultures and respiratory samples in hospitalized patients in medical and surgical wards and in the intensive care unit (ICU). Additionally, bloodstream infections with requested infectious disease consultations were reported (n = 400), determining whether these were carried out via telephone contact or at the patient's bedside. Demographic data, comorbidities, focus of infection, antimicrobial regimen, duration of treatment, length of hospitalization, and clinical outcome were analyzed. RESULTS: A total of 4569 strains of Gram-positive and -negative bacteria were isolated. An increasing trend was reported compared to the pre-pandemic period in the incidence of resistant Gram-negative bacteria, particularly in ICUs. Prior antimicrobial use and the rate of hospital-acquired infections were increased significantly during the pandemic. In the pre-pandemic period 2018-2019, a total of 246 infectious disease consultations were carried out, while during the period 2020-2022, the number was 154, with the percentage of telephone consultations 15% and 76%, respectively. Detection of the source of infection and timely administration of appropriate antimicrobial agents were more frequently recorded before the pandemic, and 28-day mortality was significantly reduced in cases with bedside consultations. CONCLUSION: The empowering of infectious disease surveillance programs and committees, rational use of antimicrobials agents, and bedside infectious disease consultations are vital in order to reduce the impact of infections caused by multidrug-resistant strains.

Hepatitis E Virus (HEV) Infection in Hemodialysis Patients: A Multicenter Epidemiological Cohort Study in North-Eastern Greece.

Hepatitis E virus (HEV), a common cause of viral hepatitis in developing countries, is mainly transmitted via the fecal-oral route, but also may be a prevalent hospital-transmitted agent among patients on regular hemodialysis due to parenteral transmission. Previous epidemiological studies among hemodialysis patients in Greece, using different diagnostic techniques, gave conflicting results. Τhe present study aimed to measure the exposure rate of hemodialysis patients of north-eastern Greece to HEV by estimating the overall seroprevalence, and to identify potential risk factors. Serum samples from all patients attending the hemodialysis centers of north-eastern Greece (n = 6) were tested for the presence of anti-HEV IgG antibodies using a modern and sensitive ELISA (Enzyme-linked Immunosorbent Assay) technique (Wantai). In total, 42 out of 405 hemodialysis patients were positive for anti-HEV IgG (10.4%), while all samples were negative for HEV RNA when tested using nested RT-PCR. HEV seropositivity among hemodialysis patients was significantly associated with area of residence and contact with specific animals (pork, deer). No association was found with religion, gender distribution and hemodialysis duration. This study showed an increased seroprevalence of HEV among hemodialysis patients in Greece. Agricultural or livestock occupation and place of residence seem to be independent factors that increase the risk of HEV infection. In conclusion, HEV infection calls for the regular screening of hemodialysis patients regardless of the hemodialysis duration or clinical symptoms.

Genetic and phenotypic assessment of the antimicrobial activity of three potential probiotic lactobacilli against human enteropathogenic bacteria.

Introduction: Lactobacilli are avid producers of antimicrobial compounds responsible for their adaptation and survival in microbe-rich matrices. The bactericidal or bacteriostatic ability of lactic acid bacteria (LAB) can be exploited for the identification of novel antimicrobial compounds to be incorporated in functional foodstuffs or pharmaceutical supplements. In this study, the antimicrobial and antibiofilm properties of Lactiplantibacillus pentosus L33, Lactiplantibacillus plantarum L125 and Lacticaseibacillus paracasei SP5, previously isolated form fermented products, were examined, against clinical isolates of Staphylococcus aureus, Salmonella enterica subsp. enterica serovar Enteritidis and Escherichia coli. Methods: The ability of viable cells to inhibit pathogen colonization on HT-29 cell monolayers, as well as their co-aggregation capacity, were examined utilizing the competitive exclusion assay. The antimicrobial activity of cell-free culture supernatants (CFCS) was determined against planktonic cells and biofilms, using microbiological assays, confocal microscopy, and gene expression analysis of biofilm formation-related genes. Furthermore, in vitro analysis was supplemented with in silico prediction of bacteriocin clusters and of other loci involved in antimicrobial activity. Results: The three lactobacilli were able to limit the viability of planktonic cells of S. aureus and E. coli in suspension. Greater inhibition of biofilm formation was recorded after co-incubation of S. enterica with the CFCS of Lc. paracasei SP5. Predictions based on sequence revealed the ability of strains to produce single or two-peptide Class II bacteriocins, presenting sequence and structural conservation with functional bacteriocins. Discussion: The efficiency of the potentially probiotic bacteria to elicit antimicrobial effects presented a strain- and pathogen-specific pattern. Future studies, utilizing multi-omic approaches, will focus on the structural and functional characterization of molecules involved in the recorded phenotypes.

A gene expression map of host immune response in human brucellosis.

Brucellosis is a common zoonotic disease caused by intracellular pathogens of the genus Brucella. Brucella infects macrophages and evades clearance mechanisms, thus resulting in chronic parasitism. Herein, we studied the molecular changes that take place in human brucellosis both in vitro and ex vivo. RNA sequencing was performed in primary human macrophages (Mφ) and polymorphonuclear neutrophils (PMNs) infected with a clinical strain of Brucella spp. We observed a downregulation in the expression of genes involved in host response, such as TNF signaling, IL-1ß production, and phagosome formation in Mφ, and phosphatidylinositol signaling and TNF signaling in PMNs, being in line with the ability of the pathogen to survive within phagocytes. Further transcriptomic analysis of isolated peripheral blood mononuclear cells (PBMCs) and PMNs from patients with acute brucellosis before treatment initiation and after successful treatment revealed a positive correlation of the molecular signature of active disease with pathways associated with response to interferons (IFN). We identified 24 common genes that were significantly altered in both PMNs and PBMCs, including genes involved in IFN signaling that were downregulated after treatment in both cell populations, and IL1R1 that was upregulated. The concentration of several inflammatory mediators was measured in the serum of these patients, and levels of IFN-γ, IL-1ß and IL-6 were found significantly increased before the treatment of acute brucellosis. An independent cohort of patients with chronic brucellosis also revealed increased levels of IFN-γ during relapse compared to remissions. Taken together, this study provides for the first time an in-depth analysis of the transcriptomic alterations that take place in human phagocytes upon infection, and in peripheral blood immune populations during active disease.

A taxonomically representative strain collection to explore xenobiotic and secondary metabolism in bacteria.

Bacteria employ secondary metabolism to combat competitors, and xenobiotic metabolism to survive their chemical environment. This project has aimed to introduce a bacterial collection enabling comprehensive comparative investigations of those functions. The collection comprises 120 strains (Proteobacteria, Actinobacteria and Firmicutes), and was compiled on the basis of the broad taxonomic range of isolates and their postulated biosynthetic and/or xenobiotic detoxification capabilities. The utility of the collection was demonstrated in two ways: first, by performing 5144 co-cultures, recording inhibition between isolates and employing bioinformatics to predict biosynthetic gene clusters in sequenced genomes of species; second, by screening for xenobiotic sensitivity of isolates against 2-benzoxazolinone and 2-aminophenol. The co-culture medium of Bacillus siamensis D9 and Lysinibacillus sphaericus DSM 28T was further analysed for possible antimicrobial compounds, using liquid chromatography-mass spectrometry (LC-MS), and guided by computational predictions and the literature. Finally, LC-MS analysis demonstrated N-acetylation of 3,4-dichloroaniline (a toxic pesticide residue of concern) by the actinobacterium Tsukamurella paurometabola DSM 20162T which is highly tolerant of the xenobiotic. Microbial collections enable "pipeline" comparative screening of strains: on the one hand, bacterial co-culture is a promising approach for antibiotic discovery; on the other hand, bioremediation is effective in combating pollution, but requires knowledge of microbial xenobiotic metabolism. The presented outcomes are anticipated to pave the way for studies that may identify bacterial strains and/or metabolites of merit in biotechnological applications.

Association between vitamin D receptor gene polymorphisms and fibrosis susceptibility in Greek patients with HCV infection.

Introduction: Hepatitis C virus (HCV) infection is a prime cause of chronic hepatitis worldwide, that often silently progresses to fibrosis, cirrhosis and hepatocellular carcinoma (HCC). Notably, the majority of individuals infected with HCV develop symptoms at late stages, often associated with liver damage that cannot revert after virus clearance. Thus, current antiviral therapy alone is rather insufficient to eliminate the global burden of HCV in the near future.During the past few years, vitamin D deficiency as well as certain single nucleotide polymorphisms in the vitamin D receptor (VDR) gene have been associated with liver fibrosis. Therefore, the aim of the present study was to investigate the possible correlation between VDR polymorphisms ApaI (rs7975232) and TaqI (rs731236) and the fibrosis stage of patients with HCV infection from Thrace, Greece. Methods: Eighty-one patients with HCV infection underwent transient elastography for the assessment of their fibrosis stage, and PCR-restriction fragment length polymorphism (RFLP) genotyping for VDR ApaI and TaqI polymorphisms. VDR genotypes were then statistically associated with the patients' fibrosis stage using ordinal regression models. Results: Non-cirrhotic stages were positively correlated with TaqI TT genotype (p=0.003) and negatively correlated with TaqI TC genotype (p=0.007). In the presence of Hardy-Weinberg equilibrium and linkage disequilibrium between the two VDR polymorphisms, mild fibrosis stages (F0-2) were correlated with ApaI/TaqI GG/TT (p=0.002) and TG/TT (p=0.008) genotypes, while cirrhotic stage F4 was associated with ApaI/TaqI TG/TC genotype (p=0.038). Conclusions: TaqI TT and ApaI/TaqI GG/TT, TG/TT and TG/TC genotypes could be explored as prognostic genetic markers for fibrosis susceptibility in HCV patients.

Local Antibiotic Delivery Systems in the Surgical Treatment of Diabetic Foot Osteomyelitis: Again, No Benefit?

This retrospective study aimed to compare the outcomes and healing parameters of 3 groups of surgical treatment combined with and without local antibiotic administration in diabetic foot osteomyelitis (DFO). Overall, 25 patients with DFO who met the criteria were included in the study. Surgical debridement was used with systemic antibiotic administration alone (group A; n = 8) or combined with local application of antibiotic-loaded polymethylmethacrylate beads (group B; n = 9) or antibiotic-loaded hydroxyapatite and calcium sulfate beads (group C; n = 8). In total, 87.5% patients in group A, 100% in group B, and 87.5% in group C healed (P = .543). Median time to healing was 17 weeks in group A, 18 weeks in group B, and 19 weeks in group C (P = .094). One patient (12.5%) in group A was amputated. DFO recurrence rate was 12.5% in group A and 12.5% in group C (P = .543). Median hospitalization was 9 days in group A, 8 days in group B, and 9 days in group C (P = .081). In conclusion, adjunctive local antibiotic therapy was not shown to improve outcomes in surgically treated DFO.

Prevalence of anti-SARS-CoV-2 IgG antibodies in a group of patients, a control group, and healthcare workers of Thrace area in Greece, by the use of two distinct methods.

INTRODUCTION: The aim of this study was to assess the clinical performance of different automated immunoassays available in Europe to detect anti-SARS-CoV-2 antibodies; an ELISA assay and a CLIA. The second goal was to estimate the seroprevalence of SARS-CoV-2 antibodies among healthcare workers in Evros area during the first pandemic wave of COVID-19. METHODS: The study included serum samples from 101 patients with confirmed COVID-19 by RT-PCR and 208 negative patients. Furthermore, it included 1036 healthcare workers (HWs) of the Evros Region, Northern Greece. The measurement of anti-SARS-CoV-2 antibodies was performed using the Abbott SARS-CoV-2 IgG and anti-SARS-CoV-2 ELISA IgG assay (Epitope Diagnostics, USA). RESULTS: Of 101 confirmed COVID-19 patients, 82 were hospitalized and 19 were outpatients. Hospitalized patients had higher IgG levels in comparison to outpatients (6.46±2.2 vs. 3.52±1.52, p<0.001). Of 208 non-COVID-19 patients only 1 was positive in both ELISA and CLIA assay. SARS-CoV-2-IgG antibodies were detected in 6 HWs out of 1036 (0.58%) with mean S/CO-value of anti-SARS-CoV-2 IgG 3.12±1.3 (confidence interval 0.95), which was lower than in COVID-19 patients (3.12 vs. 5.9; p=0.016). The clinical evaluation of two immunoassays showed remarkably high true positivity rates in the confirmed COVID-19 patients. Sensitivities obtained with CLIA and ELISA methods were 99.02% vs. 97.09% and specificities 99.52% vs 99.05% respectively. CONCLUSIONS: We found an acceptable accordance between CLIA and ELISA assays in the confirmed COVID-19 patients. In all subjects included in this study in the past medical history, the information that was obtained included details about the presence of autoimmune diseases.

COVID-19 and Antimicrobial Resistance: Data from the Greek Electronic System for the Surveillance of Antimicrobial Resistance-WHONET-Greece (January 2018-March 2021).

Changes in hospitals' daily practice due to COVID-19 pandemic may have an impact on antimicrobial resistance (AMR). We aimed to assess this possible impact as captured by the Greek Electronic System for the Surveillance of Antimicrobial Resistance (WHONET-Greece). Routine susceptibility data of 17,837 Gram-negative and Gram-positive bacterial isolates from blood and respiratory specimens of hospitalized patients in nine COVID-19 tertiary hospitals were used in order to identify potential differences in AMR trends in the last three years, divided into two periods, January 2018-March 2020 and April 2020-March 2021. Interrupted time-series analysis was used to evaluate differences in the trends of non-susceptibility before and after the changes due to COVID-19. We found significant differences in the slope of non-susceptibility trends of Acinetobacter baumannii blood and respiratory isolates to amikacin, tigecycline and colistin; of Klebsiella pneumoniae blood and respiratory isolates to meropenem and tigecycline; and of Pseudomonas aeruginosa respiratory isolates to imipenem, meropenem and levofloxacin. Additionally, we found significant differences in the slope of non-susceptibility trends of Staphylococcus aureus isolates to oxacillin and of Enterococcus faecium isolates to glycopeptides. Assessing in this early stage, through surveillance of routine laboratory data, the way a new global threat like COVID-19 could affect an already ongoing pandemic like AMR provides useful information for prompt action.

Clinical validation of optimised RT-LAMP for the diagnosis of SARS-CoV-2 infection.

We have optimised a reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay for the detection of SARS-CoV-2 from extracted RNA for clinical application. We improved the stability and reliability of the RT-LAMP assay by the addition of a temperature-dependent switch oligonucleotide to reduce self- or off-target amplification. We then developed freeze-dried master mix for single step RT-LAMP reaction, simplifying the operation for end users and improving long-term storage and transportation. The assay can detect as low as 13 copies of SARS-CoV2 RNA per reaction (25-µL). Cross reactivity with other human coronaviruses was not observed. We have applied the new RT-LAMP assay for testing clinical extracted RNA samples extracted from swabs of 72 patients in the UK and 126 samples from Greece and demonstrated the overall sensitivity of 90.2% (95% CI 83.8-94.7%) and specificity of 92.4% (95% CI 83.2-97.5%). Among 115 positive samples which Ct values were less than 34, the RT-LAMP assay was able to detect 110 of them with 95.6% sensitivity. The specificity was 100% when RNA elution used RNase-free water. The outcome of RT-LAMP can be reported by both colorimetric detection and quantifiable fluorescent reading. Objective measures with a digitized reading data flow would allow for the sharing of results for local or national surveillance.

Levels of Produced Antibodies after Vaccination with mRNA Vaccine; Effect of Previous Infection with SARS-CoV-2.

The aim of this study was to estimate the immunogenic effect of mRNA vaccine against SARS-CoV-2. This study included 510 participants who received mRNA vaccine. The measurement of anti-COVID-19 antibodies was performed using the Abbott SARS-CoV-2 IgG quantitative assay (Abbott). Overall, mean titer of anti-Spike antibodies was 19,319.2 ± 1787.5 AU/mL. Vaccination induced a robust immunogenic response in those previously infected with SARS-CoV-2 compared with non-infected subjects. Additionally, individuals that were asymptomatic after vaccination produced lower levels of antibodies compared to feverish individuals. In conclusion, remarkably high levels of anti-Spike COVID-19 antibodies were observed after vaccination.

Smell and Taste Loss Recovery Time in COVID-19 Patients and Disease Severity.

A significant proportion of people infected with SARS-CoV-2 report a new onset of smell or taste loss. The duration of the chemosensory impairment and predictive factors of recovery are still unclear. We aimed to investigate the prevalence, temporal course and recovery predictors in patients who suffered from varying disease severity. Consecutive adult patients diagnosed to be infected with SARS-CoV-2 via reverse-transcription-polymerase chain reaction (RT-PCR) at two coronavirus disease-2019 (COVID-19) Reference Hospitals were contacted to complete a survey reporting chemosensory loss, severity, timing and duration, nasal symptoms, smoking, allergic rhinitis, chronic rhinosinusitis, comorbidities and COVID-19 severity. In a cross-sectional study, we contacted 182 patients and 150 responded. Excluding the critically ill patients, 38% reported gustatory and 41% olfactory impairment (74% severe/anosmia). Most of the patients (88%) recovered their sense of smell by two months (median: 11.5 days; IQR: 13.3). For 23%, the olfactory loss lasted longer than a month. There were no significant differences in the prevalence and duration of chemosensory loss between groups of varying COVID-19 severity, and sexes (all p > 0.05). Moderate hyposmia resolved quicker than more severe loss (p = 0.04). Smell and taste loss are highly prevalent in COVID-19. Most patients recover fast, but nearly one out of ten have not recovered in two months.

The prevalence of HCV RNA positivity in anti-HCV antibodies-negative hemodialysis patients in Thrace Region. Multicentral study.

INTRODUCTION: HCV infection in patients under hemodialysis for end stage chronic kidney disease (ESCKD) may exist despite the absence of anti-HCV antibodies. Molecular methods are widely accepted as "gold standard" techniques for the detection of viral RNA. However, the molecular methods are more expensive in comparison to conventional methods and their replacement is not cost-effective. The aim of this study was to estimate the prevalence of HCV RNA positivity in anti-HCV negative hemodialysis patients and evaluate new diagnostic methods for the detection and the monitoring of hepatitis C in ESCKD patients. METHODS: The study was performed in four hospitals of Thrace region of Greece and 233 patients with no history of hepatitis C were enrolled. Measurement of anti-HCV antibodies and HCV core antigen was performed by microparticle chemiluminescence immunoassay. Molecular detection of viral RNA was performed by the real-time RT PCR. RESULTS: The mean age of the patients was 64.9 ± 23.3 years. HCV-Ag was positive in 2/233 patients (0.86%). Nevertheless, viral RNA was negative in those patients. CONCLUSIONS: The results of the present study showed that the incidence of HCV-RNA in patients with negative anti-HCV Abs, in hemodialysis patients in Thrace region of Greece was negligible (0/233).

Estimation of low-density lipoprotein cholesterol by machine learning methods.

BACKGROUND: Accurate determination of low-density lipoprotein cholesterol (LDL) is important for coronary heart disease risk assessment and atherosclerosis. Apart from direct determination of LDL values, models (or equations) are used. A more recent approach is the use of machine learning (ML) algorithms. METHODS: ML algorithms were used for LDL determination (regression) from cholesterol, HDL and triglycerides. The methods used were multivariate Linear Regression (LR), Support Vector Machines (SVM), Extreme Gradient Boosting (XGB) and Deep Neural Networks (DNN), in both larger and smaller data sets. Also, LDL values were classified according to both NCEP III and European Society of Cardiology guidelines. RESULTS: The performance of regression was assessed by the Standard Error of the Estimate. ML methods performed better than established equations (Friedewald and Martin). The performance all ML methods was comparable for large data sets and was affected by the divergence of the train and test data sets, as measured by the Jensen-Shannon divergence. Classification accuracy was not satisfactory for any model. CONCLUSIONS: Direct determination of LDL is the most preferred route. When not available, ML methods can be a good substitute. Not only deep neural networks but other, less computationally expensive methods can work as well as deep learning.