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1.
J Virol Methods ; 308: 114587, 2022 Oct.
Article in English | MEDLINE | ID: covidwho-1936900

ABSTRACT

PURPOSE: To evaluate filter paper as a means to transport oro/nasopharyngeal samples from laboratories with few resources for SARS-CoV-2 detection by RT-qPCR in a central laboratory that usually performs this technique as routine. METHODS: A total of 40 specimens were evaluated in parallel by RT-qPCR carried out after RNA extraction using two different protocols: direct RNA extraction (Protocol A - reference method) and RNA extraction after impregnation in filter paper (Protocol B). RESULTS: The RT-qPCR for SARS-CoV-2 using Protocol B presented 97.22% (35/36) of agreement for SARS-CoV-2-positive samples when compared to the reference method (Protocol A), even for specimens with low viral load (increased Ct values). Noteworthy, three clinical specimens which were categorized as inconclusive by Protocol A presented amplification of both N1 and N2 targets using Protocol B, presenting positive results for SARS-CoV-2. CONCLUSION: The use of filter paper to transport oro/nasopharyngeal clinical samples presented very satisfactory results to detect SARS-CoV-2 by RT-qPCR. In addition, it proved to be a feasible and sensitive approach, being able to generate the detection of SARS-CoV-2 even at low concentrations, without presenting false-negative results.

2.
EBioMedicine ; 70: 103502, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1330765

ABSTRACT

BACKGROUND: Since 2020 SARS-CoV-2 spreads pandemically, infecting more than 119 million people, causing >2·6 million fatalities. Symptoms of SARS-CoV-2 infection vary greatly, ranging from asymptomatic to fatal. Different populations react differently to the disease, making it very hard to track the spread of the infection in a population. Measuring specific anti-SARS-CoV-2 antibodies is an important tool to assess the spread of the infection or successful vaccinations. To achieve sufficient sample numbers, alternatives to venous blood sampling are needed not requiring medical personnel or cold-chains. Dried-blood-spots (DBS) on filter-cards have been used for different studies, but not routinely for serology. METHODS: We developed a semi-automated protocol using self-sampled DBS for SARS-CoV-2 serology. It was validated in a cohort of matched DBS and venous-blood samples (n = 1710). Feasibility is demonstrated with two large serosurveys with 10247 company employees and a population cohort of 4465 participants. FINDINGS: Sensitivity and specificity reached 99·20% and 98·65%, respectively. Providing written instructions and video tutorials, 99·87% (4465/4471) of the unsupervised home sampling DBS cards could be analysed. INTERPRETATION: DBS-sampling is a valid and highly reliable tool for large scale serosurveys. We demonstrate feasibility and accuracy with a large validation cohort including unsupervised home sampling. This protocol might be of big importance for surveillance in resource-limited settings, providing low-cost highly accurate serology data. FUNDING: Provided by Bavarian State Ministry of Science and the Arts, LMU University-Hospital; Helmholtz-Centre-Munich, German Ministry for Education and Research (project01KI20271); University of Bonn; University of Bielefeld; the Medical Biodefense Research Program of Bundeswehr-Medical-Service; Euroimmun, RocheDiagnostics provided discounted kits and machines.


Subject(s)
Antibodies, Viral/immunology , Biological Assay/methods , COVID-19 Serological Testing/methods , COVID-19/blood , COVID-19/immunology , Dried Blood Spot Testing/methods , SARS-CoV-2/immunology , Asymptomatic Infections , Cohort Studies , Humans , Longitudinal Studies , Sensitivity and Specificity , Specimen Handling/methods , Vaccination/methods
3.
Multidiscip Respir Med ; 15(1): 664, 2020 Jan 28.
Article in English | MEDLINE | ID: covidwho-1088995

ABSTRACT

BACKGROUND: Medical face masks are integral personal protective equipment against infectious airborne disease and become scarce during epidemic outbreaks such as COVID-19. A novel, sustainably manufactured face mask with antimicrobial and anti-inflammatory properties from oil of Folium Plectranthii amboinicii can be an effective alternative to internationally sold masks. METHODS: This prospective, randomized study assigned subjects (n=67) to either conventional surgical face mask or Lamdong Medical College (LMC) face mask for three hours. Fractional concentration of nitric oxide in exhaled breath (FENO) and peak expiratory flow (PEF) was measured before and after mask use. Subjective reporting on respiratory symptoms was also analyzed. Masks were then incubated and analyzed for microorganism growth. RESULTS: Subjects assigned the LMC mask had a lowered FENO (p<0.05) compared to conventional face masks after mask wearing. Subjects with LMC mask use reported higher comfortability (p<0.05), breathability (p<0.05), and lower allergy symptoms (p<0.05). The LMC mask has visually less microorganism growth in the cultured medium, measured by sterile ring radius. CONCLUSIONS: The LMC face mask is a renewably manufactured personal protective tool with antibacterial capacity that can serve as an effective alternative to internationally sold surgical face mask during shortage of mask due to COVID-19.

4.
Bioanalysis ; 13(1): 13-28, 2021 Jan.
Article in English | MEDLINE | ID: covidwho-977787

ABSTRACT

Aim: Coronavirus disease 2019 antibody testing often relies on venous blood collection, which is labor-intensive, inconvenient and expensive compared with finger-stick capillary dried blood spot (DBS) collection. The purpose of our work was to determine if two commercially available anti-severe acute respiratory syndrome coronavirus 2 enzyme-linked immunosorbent assays for IgG antibodies against spike S1 subunit and nucleocapsid proteins could be validated for use with DBS. Materials & methods: Kit supplied reagents were used to extract DBS, and in-house DBS calibrators were included on every run. Results: Positive/negative concordance between DBS and serum was 100/99.3% for the spike S1 subunit assay and 100/98% for the nucleocapsid assay. Conclusion: Validation of the DBS Coronavirus disease 2019 IgG antibody assays demonstrated that serum and DBS can produce equivalent results with minimal kit modifications.


Subject(s)
COVID-19 Testing/standards , COVID-19/diagnosis , Dried Blood Spot Testing/standards , Enzyme-Linked Immunosorbent Assay/standards , SARS-CoV-2/immunology , Antibodies, Viral/chemistry , Antigens, Viral/blood , Antigens, Viral/immunology , COVID-19/blood , COVID-19/immunology , COVID-19/virology , Coronavirus Nucleocapsid Proteins/blood , Coronavirus Nucleocapsid Proteins/immunology , Female , Humans , Immunoglobulin G/chemistry , Male , Middle Aged , Phosphoproteins/blood , Phosphoproteins/immunology , Reagent Kits, Diagnostic/standards , Reproducibility of Results , Sensitivity and Specificity , Spike Glycoprotein, Coronavirus/blood , Spike Glycoprotein, Coronavirus/immunology
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