Breakthrough COVID-19 in Vaccinated Patients with Haematologic Malignancies-The First Single-Centre Experience from the Czech Republic.

Vaccination is an important tool in the fight against the COVID-19 pandemic in patients with haematologic malignancies. The paper provides an analysis of the course of breakthrough SARS-CoV-2 infection in a group of vaccinated patients with haematological malignancy and a comparison with a historical cohort of 96 non-vaccinated patients with haematologic malignancies and bone marrow failure syndromes (two patients) in the treatment of COVID-19. A severe or critical course of COVID-19 was significantly less frequent in the group of vaccinated patients (10.2% vs. 31.4%, p = 0.003). The need for hospitalisation due to COVID-19 was significantly lower in vaccinated patients (27.1% vs. 72.6%, p < 0.0001) and the duration of hospitalisation was significantly shorter (10 vs. 14 days, p = 0.045). Vaccinated patients were insignificantly less likely to require oxygen therapy during infection. COVID-19 mortality was significantly higher in non-vaccinated patients (15.6% vs. 5.1%, p = 0.047). The paper demonstrated a significant positive effect of vaccination against COVID-19 on a less severe clinical course of infection, lower need for hospitalisation and mortality. However, the results need to be evaluated even in the context of new antivirals and monoclonal antibodies against SARS-CoV-2 or virus mutations with different biological behaviour.

Bacterial Resistance to Antibiotics and Clonal Spread in COVID-19-Positive Patients on a Tertiary Hospital Intensive Care Unit, Czech Republic.

This observational retrospective study aimed to analyze whether/how the spectrum of bacterial pathogens and their resistance to antibiotics changed during the worst part of the COVID-19 pandemic (1 November 2020 to 30 April 2021) among intensive care patients in University Hospital Olomouc, Czech Republic, as compared with the pre-pandemic period (1 November 2018 to 30 April 2019). A total of 789 clinically important bacterial isolates from 189 patients were cultured during the pre-COVID-19 period. The most frequent etiologic agents causing nosocomial infections were strains of Klebsiella pneumoniae (17%), Pseudomonas aeruginosa (11%), Escherichia coli (10%), coagulase-negative staphylococci (9%), Burkholderia multivorans (8%), Enterococcus faecium (6%), Enterococcus faecalis (5%), Proteus mirabilis (5%) and Staphylococcus aureus (5%). Over the comparable COVID-19 period, a total of 1500 bacterial isolates from 372 SARS-CoV-2-positive patients were assessed. While the percentage of etiological agents causing nosocomial infections increased in Enterococcus faecium (from 6% to 19%, p < 0.0001), Klebsiella variicola (from 1% to 6%, p = 0.0004) and Serratia marcescens (from 1% to 8%, p < 0.0001), there were significant decreases in Escherichia coli (from 10% to 3%, p < 0.0001), Proteus mirabilis (from 5% to 2%, p = 0.004) and Staphylococcus aureus (from 5% to 2%, p = 0.004). The study demonstrated that the changes in bacterial resistance to antibiotics are ambiguous. An increase in the frequency of ESBL-positive strains of some species (Serratia marcescens and Enterobacter cloacae) was confirmed; on the other hand, resistance decreased (Escherichia coli, Acinetobacter baumannii) or the proportion of resistant strains remained unchanged over both periods (Klebsiella pneumoniae, Enterococcus faecium). Changes in pathogen distribution and resistance were caused partly due to antibiotic selection pressure (cefotaxime consumption increased significantly in the COVID-19 period), but mainly due to clonal spread of identical bacterial isolates from patient to patient, which was confirmed by the pulse field gel electrophoresis methodology. In addition to the above shown results, the importance of infection prevention and control in healthcare facilities is discussed, not only for dealing with SARS-CoV-2 but also for limiting the spread of bacteria.

Antibiotic treatment issues in patients with COVID-19.

The COVID-19 pandemic may increase the current threat of antimicrobial resistance and exacerbate another, rather silent, pandemic posed by the increasing frequency of multidrug-resistant bacterial pathogens and the associated potential for loss of effective antibiotics. Antibiotic treatment has often been used in patients hospitalized for COVID-19 due to concerns about possible bacterial co-infection, as confirmed by previous experience with viral respiratory infections such as H1N1 influenza, SARS and MERS. Concerns or unknowns related to the COVID-19 pandemic have also affected physicians behavior, including the use of antibiotics. However, the high rate of antibiotic use in patients, especially those with mild to moderate COVID-19 disease, is inconsistent with the actual incidence of bacterial co-infections and/or secondary respiratory infections. Thus, it is clear that a careful assessment of the role of antibiotic treatment in patients hospitalized for COVID-19 is required. According to the current WHO recommendation, the application of antibiotics is especially suitable for patients with severe/critical degree of respiratory insufficiency requiring intensive oxygen therapy, artificial lung ventilation or support by extracorporeal membrane oxygenation.

Seroprevalence of Measles Antibodies in the Population of the Olomouc Region, Czech Republic-Comparison of the Results of Four Laboratories.

OBJECTIVES: Although the incidence of measles has decreased globally since the introduction of regular vaccination, its frequency has increased again in recent years. The study is focused on data from the Olomouc Region in the Czech Republic analyzed in four laboratories. The obtained results were compared with already published data. METHODS: The data were provided by individual laboratories in an anonymized form-age at the time of the examination, sex, and result of test. Samples were collected between June 2018 and September 2019 and evaluated on the scale positive-borderline-negative. RESULTS: A total of 7962 sera samples were evaluated using three different methods-two types of ELISA tests and CLIA. Positive result was issued in a total of 62.6 percent of samples, but the results of individual laboratories varied widely from 55.5 to 70.8 percent. However, the same trend with the highest levels of antibodies in people born before beginning of vaccination was observed. CONCLUSIONS: Data show significantly different results depending on the individual laboratories and the detection kits used. The underestimation of the proportion of positive results can cause problems in selecting individuals for revaccination with a live vaccine, which may fail in weakly positive individuals.

Pulmonary Complications after COVID-19.

Coronavirus disease 2019 (COVID-19) is a threat to patients not only because of its acute course, but also because of various complications occurring in the following period, that is, more than 28 days after the onset of acute infection. The present study identified a total of 121 patients hospitalized 29 or more days after the first positive result of a PCR test for SARS-CoV-2, of whom 98 patients were included in the study. Patients were divided into two groups by the time interval between the positive COVID-19 test result and hospitalization date. The time intervals were week 5-11 in an ongoing-COVID group (57.1% of patients) and 12 or more weeks in a post-COVID-group (42.9%). The most frequent reason for hospitalization was respiratory tract infection (58.2%). Pneumonia accounted for 77.2% of these cases. Other reasons for hospitalization were interstitial lung disease (22.4%), pulmonary embolism (8.2%), and sarcoidosis (6.1%). The study group was further divided according to the causes of hospitalization into subgroups with infections and other causes. In the group with infectious diseases, there was a shorter time period between PCR positivity and hospitalization and there were significantly more frequent non-respiratory complications. In the entire sample, the in-hospital mortality was 5.1%.

Routine SARS-CoV-2 RT-PCR testing before digestive endoscopy during the peak of the pandemic - a single tertiary center experience.

BACKGROUND AND AIMS: COVID-19 pandemic has impacted on all endoscopy centers in the Czech Republic, that belongs to the most affected countries in the world. The aim of our study was to analyze all procedures following routine RT-PCR testing in our tertiary center during the peak of the pandemic. METHODS: We retrospectively analyzed all procedures performed from October 2020 to January 2021 after a new RT-PCR center had been set up. Main outcomes were type of scheduled procedure, indication, rate of therapeutic interventions and rate of new relevant and malignant findings. Comparison to the same period before the pandemic and SARS-CoV-2 infection in endoscopy staff are also reported. RESULTS: A total of 1,953 procedures were performed. 624 patients were referred with a negative RT-PCR test and the remaining 1,346 patients were tested in the new center. 1,293 negative tests led to 1,329 procedures. A new relevant finding was reported in 589 (44.3%), including new malignancy in 56 (4.2%). 53 patients tested positive (3.9%). There was a reduction by 9% in the number of all procedures compared to the same period before the pandemic and an increase in the number of screening colonoscopies and ERCP procedures. In the study period, 9 of 54 staff members contracted SARS-CoV-2 infection. CONCLUSIONS: Routine RT-PCR testing of patients scheduled for elective endoscopy during the peak of COVID-19 pandemic enabled us to essentially maintain our unit productivity, including activities such as screening colonoscopy, endoscopic resection and pancreatobiliary endoscopy.

Clostridioides difficile and Vancomycin-Resistant Enterococci in COVID-19 Patients with Severe Pneumonia.

Broad-spectrum antibiotics administered to patients with severe COVID-19 pneumonia pose a risk of infection caused by Clostridioides difficile. This risk is reduced mainly by strict hygiene measures and early de-escalation of antibiotic therapy. Recently, oral vancomycin prophylaxis (OVP) has also been discussed. This retrospective study aimed to assess the prevalence of C. difficile in critical COVID-19 patients staying in an intensive care unit of a tertiary hospital department of anesthesiology, resuscitation, and intensive care from November 2020 to May 2021 and the rates of vancomycin-resistant enterococci (VRE) after the introduction of OVP and to compare the data with those from controls in the pre-pandemic period (November 2018 to May 2019). During the COVID-19 pandemic, there was a significant increase in toxigenic C. difficile rates to 12.4% of patients, as compared with 1.6% in controls. The peak rates were noted in February 2021 (25% of patients), immediately followed by initiation of OVP, changes to hygiene precautions, and more rapid de-escalation of antibiotic therapy. Subsequently, toxigenic C. difficile detection rates started to fall. There was a nonsignificant increase in VRE detected in non-gastrointestinal tract samples to 8.9% in the COVID-19 group, as compared to 5.3% in the control group. Molecular analysis confirmed mainly clonal spread of VRE.

COVID-19 in 96 Patients With Hematologic Disease: The First Single-center Experience From the Czech Republic.

BACKGROUND: Coronavirus disease 2019 (COVID-19) represents an important infectious complication associated with high mortality rates in patients with hematologic diseases. There have not been published any epidemiologic studies from Czech Republic so far. PATIENTS AND METHODS: This study is the first analysis of patients with hematologic malignancies and bone marrow failure syndromes treated at single hematology center in the Czech Republic between March 1 and December 31, 2020, in whom COVID-19 infection was confirmed. RESULTS: The sample comprised 96 patients aged 26 to 84 years (median, 66.0 years). At the time of their COVID-19 diagnosis, 75 patients (78.1%) were treated for hematologic diseases. Twenty-seven patients (28.1%) in the sample had complete remission (CR) of their hematologic disease. They were nonsignificantly more likely to have asymptomatic to moderate COVID-19 infection than those who failed to achieve CR (74.1% vs. 56.5%; P = .06). A more severe course of the infection was significantly correlated with older age (P = .047). Lung involvement was also statistically significantly associated with older age (P = .045). Over the study period, a total of 15 patients died. Age greater than 60 years was significantly associated with deaths from COVID-19 (P = .036), with failure to achieve CR having a statistically nonsignificant impact on mortality (P = .22). CONCLUSION: These results confirm the prognostic significance of age for achieving treatment response of hematologic disease as well as the severity and mortality of COVID-19 in hematology patients.

Human virus detection with graphene-based materials.

Our recent experience of the COVID-19 pandemic has highlighted the importance of easy-to-use, quick, cheap, sensitive and selective detection of virus pathogens for the efficient monitoring and treatment of virus diseases. Early detection of viruses provides essential information about possible efficient and targeted treatments, prolongs the therapeutic window and hence reduces morbidity. Graphene is a lightweight, chemically stable and conductive material that can be successfully utilized for the detection of various virus strains. The sensitivity and selectivity of graphene can be enhanced by its functionalization or combination with other materials. Introducing suitable functional groups and/or counterparts in the hybrid structure enables tuning of the optical and electrical properties, which is particularly attractive for rapid and easy-to-use virus detection. In this review, we cover all the different types of graphene-based sensors available for virus detection, including, e.g., photoluminescence and colorimetric sensors, and surface plasmon resonance biosensors. Various strategies of electrochemical detection of viruses based on, e.g., DNA hybridization or antigen-antibody interactions, are also discussed. We summarize the current state-of-the-art applications of graphene-based systems for sensing a variety of viruses, e.g., SARS-CoV-2, influenza, dengue fever, hepatitis C virus, HIV, rotavirus and Zika virus. General principles, mechanisms of action, advantages and drawbacks are presented to provide useful information for the further development and construction of advanced virus biosensors. We highlight that the unique and tunable physicochemical properties of graphene-based nanomaterials make them ideal candidates for engineering and miniaturization of biosensors.