BACKGROUND: Testing of pooled samples is an effective strategy for increasing testing capacity while saving resources and time. This study aimed to validate pooled testing and gather real-life data on its use for Covid-19 surveillance with a gargle lavage (GL) self-sampling strategy. METHODS: Two-stage pooled testing with pools of 6 and 12 samples was used for preventive testing of an asymptomatic population and Covid-19 surveillance in Czech schools. Both GL and nasopharyngeal swabs were used for sampling. RESULTS: In total, 61,111 samples were tested. The use of pooled testing for large-scale Covid-19 surveillance reduced consumable costs by almost 75% and increased testing capacity up to 3.8-fold compared to standard methods. RT-PCR experiments revealed a minimal loss of sensitivity (0-2.2%) when using pooled samples, enabling the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genes with Ct values >35. The minor loss of sensitivity was counterbalanced by a significantly increased throughput and the ability to substantially increase testing frequencies. CONCLUSIONS: Pooled testing is considerably more cost-effective and less time-consuming than standard testing for large-scale Covid-19 surveillance even when the prevalence of SARS-CoV-2 is fluctuating. Gargle lavage self-sampling is a non-invasive technique suitable for sample collection without a healthcare worker's assistance.

• Klíčová slova
• Covid-19 surveillance, Pooled testing, RT-PCR, gargle lavage, self-sampling,
• MeSH
• COVID-19 * diagnóza   epidemiologie   MeSH
• lidé MeSH
• nazofarynx * virologie   MeSH
• odběr biologického vzorku * metody   MeSH
• SARS-CoV-2 * genetika   izolace a purifikace   MeSH
• senzitivita a specificita MeSH
• testování na COVID-19 průkazem nukleové kyseliny metody   MeSH
• testování na COVID-19 metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH

BACKGROUND: Although people with HIV might be at risk of severe outcomes from infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; coronavirus 2019 [COVID-19]), regional and temporal differences in SARS-CoV-2 testing in people with HIV across Europe have not been previously described. METHODS: We described the proportions of testing, positive test results, and hospitalizations due to COVID-19 between 1 January 2020 and 31 December 2021 in the EuroSIDA cohort and the factors associated with being tested for SARS-CoV-2 and with ever testing positive. RESULTS: Of 9012 participants, 2270 (25.2%, 95% confidence interval [CI] 24.3-26.1) had a SARS-CoV-2 polymerase chain reaction test during the study period (range: 38.3% in Northern to 14.6% in Central-Eastern Europe). People from Northern Europe, women, those aged <40 years, those with CD4 cell count <350 cells/mm3, and those with previous cardiovascular disease or malignancy were significantly more likely to have been tested, as were people with HIV in 2021 compared with those in 2020. Overall, 390 people with HIV (4.3%, 95% CI 3.9-4.8) tested positive (range: 2.6% in Northern to 7.1% in Southern Europe), and the odds of testing positive were higher in all regions than in Northern Europe and in 2021 than in 2020. In total, 64 people with HIV (0.7%, 95% CI 0.6-0.9) were hospitalized, of whom 12 died. Compared with 2020, the odds of positive testing decreased in all regions in 2021, and the associations with cardiovascular disease, malignancy, and use of tenofovir disoproxil fumarate disappeared in 2021. Among study participants, 58.9% received a COVID-19 vaccine (range: 72.0% in Southern to 14.8% in Eastern Europe). CONCLUSIONS: We observed large heterogeneity in SARS-CoV-2 testing and positivity and a low proportion of hospital admissions and deaths across the regions of Europe.

• Klíčová slova
• COVID‐19, Europe, HIV, SARS‐CoV‐2 testing,
• MeSH
• COVID-19 * epidemiologie   diagnóza   MeSH
• dospělí MeSH
• HIV infekce * farmakoterapie   epidemiologie   MeSH
• hospitalizace * statistika a číselné údaje   MeSH
• kohortové studie MeSH
• lidé středního věku MeSH
• lidé MeSH
• počet CD4 lymfocytů MeSH
• rizikové faktory MeSH
• SARS-CoV-2 * MeSH
• senioři MeSH
• testování na COVID-19 statistika a číselné údaje   metody   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Evropa epidemiologie   MeSH

Recent experience with the COVID-19 pandemic should be a lesson learnt with respect to the effort we have to invest in the development of new strategies for the treatment of viral diseases, along with their cheap, easy, sensitive, and selective detection. Since we live in a globalized world where just hours can play a crucial role in the spread of a virus, its detection must be as quick as possible. Thanks to their chemical stability, photostability, and superior biocompatibility, carbon dots are a kind of nanomaterial showing great potential in both the detection of various virus strains and a broad-spectrum antiviral therapy. The biosensing and antiviral properties of carbon dots can be tuned by the selection of synthesis precursors as well as by easy post-synthetic functionalization. In this review, we will first summarize current options of virus detection utilizing carbon dots by either electrochemical or optical biosensing approaches. Secondly, we will cover and share the up-to-date knowledge of carbon dots' antiviral properties, which showed promising activity against various types of viruses including SARS-CoV-2. The mechanisms of their antiviral actions will be further adressed as well. Finally, we will discuss the advantages and distadvantages of the use of carbon dots in the tangled battle against viral infections in order to provide valuable informations for further research and development of new virus biosensors and antiviral therapeutics.

• Klíčová slova
• Antiviral, Biosensors, COVID-19, Carbon dots, Coronavirus, Functionalization of carbon dots, Virus detection,
• MeSH
• antivirové látky farmakologie   MeSH
• biokompatibilní materiály MeSH
• biosenzitivní techniky MeSH
• cílená molekulární terapie MeSH
• COVID-19 diagnóza   terapie   MeSH
• elektrochemie MeSH
• farmakoterapie COVID-19 * MeSH
• fototerapie MeSH
• kvantové tečky * MeSH
• lidé MeSH
• nanostruktury MeSH
• polymery MeSH
• SARS-CoV-2 MeSH
• testování na COVID-19 metody   MeSH
• uhlík chemie   MeSH
• virové nemoci MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• antivirové látky MeSH
• biokompatibilní materiály MeSH
• polymery MeSH
• uhlík MeSH

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.

• Klíčová slova
• COVID-19, Health care–associated infection, Hematologic malignancy, Mortality, SARS-CoV-2,
• MeSH
• COVID-19 * komplikace   diagnóza   epidemiologie   terapie   MeSH
• dospělí MeSH
• hematologické nádory komplikace   diagnóza   epidemiologie   terapie   MeSH
• hospitalizace statistika a číselné údaje   MeSH
• krevní nemoci * komplikace   diagnóza   epidemiologie   terapie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mortalita MeSH
• prevalence MeSH
• progrese nemoci MeSH
• SARS-CoV-2 fyziologie   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• syndromy selhání kostní dřeně komplikace   diagnóza   epidemiologie   terapie   MeSH
• testování na COVID-19 metody   statistika a číselné údaje   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH

The specificity of a diagnostic assay depends upon the purity of the biomolecules used as a probe. To get specific and accurate information of a disease, the use of synthetic peptides in diagnostics have increased in the last few decades, because of their high purity profile and ability to get modified chemically. The discovered peptide probes are used either in imaging diagnostics or in non-imaging diagnostics. In non-imaging diagnostics, techniques such as Enzyme-Linked Immunosorbent Assay (ELISA), lateral flow devices (i.e., point-of-care testing), or microarray or LC-MS/MS are used for direct analysis of biofluids. Among all, peptide-based ELISA is considered to be the most preferred technology platform. Similarly, peptides can also be used as probes for imaging techniques, such as single-photon emission computed tomography (SPECT) and positron emission tomography (PET). The role of radiolabeled peptides, such as somatostatin receptors, interleukin 2 receptor, prostate specific membrane antigen, αβ3 integrin receptor, gastrin-releasing peptide, chemokine receptor 4, and urokinase-type plasminogen receptor, are well established tools for targeted molecular imaging ortumor receptor imaging. Low molecular weight peptides allow a rapid clearance from the blood and result in favorable target-to-non-target ratios. It also displays a good tissue penetration and non-immunogenicity. The only drawback of using peptides is their potential low metabolic stability. In this review article, we have discussed and evaluated the role of peptides in imaging and non-imaging diagnostics. The most popular non-imaging and imaging diagnostic platforms are discussed, categorized, and ranked, as per their scientific contribution on PUBMED. Moreover, the applicability of peptide-based diagnostics in deadly diseases, mainly COVID-19 and cancer, is also discussed in detail.

• Klíčová slova
• ELISA, PET, SPECT, diagnostic, imaging diagnostic, microarray, non-imaging diagnostic, peptides,
• MeSH
• COVID-19 diagnóza   virologie   MeSH
• databáze faktografické MeSH
• ELISA metody   MeSH
• jednofotonová emisní výpočetní tomografie metody   MeSH
• lidé MeSH
• peptidy analýza   MeSH
• pozitronová emisní tomografie metody   MeSH
• receptory somatostatinu MeSH
• SARS-CoV-2 izolace a purifikace   MeSH
• tandemová hmotnostní spektrometrie metody   MeSH
• testování na COVID-19 metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• peptidy MeSH
• receptory somatostatinu MeSH

The early identification of asymptomatic yet infectious cases is vital to curb the 2019 coronavirus (COVID-19) pandemic and to control the disease in the post-pandemic era. In this paper, we propose a fast, inexpensive and high-throughput approach using painless nasal-swab self-collection followed by direct RT-qPCR for the sensitive PCR detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This approach was validated in a large prospective cohort study of 1038 subjects, analysed simultaneously using (1) nasopharyngeal swabs obtained with the assistance of healthcare personnel and analysed by classic two-step RT-qPCR on RNA isolates and (2) nasal swabs obtained by self-collection and analysed with direct RT-qPCR. Of these subjects, 28.6% tested positive for SARS-CoV-2 using nasopharyngeal swab sampling. Our direct RT-qPCR approach for self-collected nasal swabs performed well with results similar to those of the two-step RT-qPCR on RNA isolates, achieving 0.99 positive and 0.98 negative predictive values (cycle threshold [Ct] < 37). Our research also reports on grey-zone viraemia, including samples with near-cut-off Ct values (Ct ≥ 37). In all investigated subjects (n = 20) with grey-zone viraemia, the ultra-small viral load disappeared within hours or days with no symptoms. Overall, this study underscores the importance of painless nasal-swab self-collection and direct RT-qPCR for mass testing during the SARS-CoV-2 pandemic and in the post-pandemic era.

• Klíčová slova
• COVID-19, Mass molecular testing, Nasal mid-turbinate swab, PCR diagnostics, Post-pandemic era, Self-collection,
• MeSH
• COVID-19 diagnóza   prevence a kontrola   MeSH
• diagnostické testy rutinní metody   MeSH
• klinické laboratorní techniky metody   MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• lidé MeSH
• odběr biologického vzorku metody   MeSH
• plošný screening metody   MeSH
• průzkumy a dotazníky MeSH
• samovyšetření metody   MeSH
• SARS-CoV-2 genetika   MeSH
• senzitivita a specificita MeSH
• testování na COVID-19 metody   MeSH
• virová nálož metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• validační studie MeSH

Antigen testing for SARS-CoV-2 (AGT) is generally considered inferior to RT-PCR testing in terms of sensitivity. However, little is known about the infectiousness of RT-PCR positive patients who pass undetected by AGT. In a screening setting for mildly symptomatic or asymptomatic patients with high COVID-19 prevalence (30-40%), 1141 patients were tested using one of five AGTs and RT-PCR. Where the results differed, virus viability in the samples was tested on cell culture (CV-1 cells). The test battery included AGTs by JOYSBIO, Assure Tech, SD Biosensor, VivaChek Biotech and NDFOS. Sensitivities of the ATGs compared to RT-PCR ranged from 42% to 76%. The best test yielded a 76% sensitivity, 97% specificity, 92% positive, and 89% negative predictive values, respectively. However, in the best performing ATG tests, almost 90% of samples with "false negative" AGT results contained no viable virus. Corrected on the virus viability, sensitivities grew to 81-97% and, with one exception, the tests yielded high specificities >96%. Performance characteristics of the best test after adjustment were 96% sensitivity, 97% specificity, 92% positive, and 99% negative predictive values (high prevalence population). We, therefore, believe that virus viability should be considered when assessing the AGT performance. Also, our results indicate that a well-performing antigen test could in a high-prevalence setting serve as an excellent tool for identifying patients shedding viable virus. We also propose that the high proportion of RT-PCR-positive samples containing no viable virus in the group of "false negatives" of the antigen test should be further investigated with the aim of possibly preventing needless isolation of such patients.

• Klíčová slova
• COVID-19, RT-PCR, SARS-CoV-2, antigen testing, infectiousness, viability,
• MeSH
• antigeny virové analýza   MeSH
• COVID-19 diagnóza   imunologie   MeSH
• dospělí MeSH
• falešně negativní reakce MeSH
• lidé středního věku MeSH
• lidé MeSH
• mikrobiální viabilita * MeSH
• plošný screening MeSH
• SARS-CoV-2 imunologie   MeSH
• senzitivita a specificita MeSH
• sérologické testy metody   MeSH
• testování na COVID-19 průkazem nukleové kyseliny MeSH
• testování na COVID-19 metody   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antigeny virové MeSH

Plasma specimens from coronavirus disease 2019 patients were double-tested for anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies by two different batches of MAGLUMI 2019-nCov immunoglobulin M/immunoglobulin G (IgM/IgG) assays to evaluate IgM/IgG levels, qualitative interpretation, antibody kinetics, and linearity of diluted specimen. Here we show that (i) high-level IgM specimens need to be diluted with negative human plasma but not kit diluents and (ii) measured anti-SARS-CoV-2 IgM/IgG concentrations are substantially higher with later marketed immunoassay batch leading to (iii) the change of qualitative interpretation (positive vs. negative) in 12.3% of specimens measured for IgM, (iv) the informative time-course pattern of antibody production only when data from different immunoassay batches are not combined.

• Klíčová slova
• CLIA, anti-SARS-CoV-2 IgG, anti-SARS-CoV-2 IgM, inter-assay batch variation, interpretative inconsistency,
• MeSH
• COVID-19 krev   imunologie   MeSH
• imunoanalýza metody   MeSH
• imunoglobulin G krev   imunologie   MeSH
• imunoglobulin M krev   imunologie   MeSH
• lidé MeSH
• luminiscence MeSH
• luminiscenční měření metody   MeSH
• protilátky virové imunologie   MeSH
• SARS-CoV-2 imunologie   MeSH
• senzitivita a specificita MeSH
• testování na COVID-19 metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• imunoglobulin G MeSH
• imunoglobulin M MeSH
• protilátky virové MeSH