ABSTRACT
A novel multiplex loop-mediated isothermal amplification (LAMP) method combined with DNA chromatography was developed for the simultaneous detection of three important respiratory disease-causing viruses: severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus, and influenza B virus. Amplification was performed at a constant temperature, and a positive result was confirmed by a visible colored band. An in-house drying protocol with trehalose was used to prepare the dried format multiplex LAMP test. Using this dried multiplex LAMP test, the analytical sensitivity was determined to be 100 copies for each viral target and 100-1000 copies for the simultaneous detection of mixed targets. The multiplex LAMP system was validated using clinical COVID-19 specimens and compared with the real-time qRT-PCR method as a reference test. The determined sensitivity of the multiplex LAMP system for SARS-CoV-2 was 71% (95% CI: 0.62-0.79) for cycle threshold (Ct) ≤ 35 samples and 61% (95% CI: 0.53-0.69) for Ct ≤40 samples. The specificity was 99% (95%CI: 0.92-1.00) for Ct ≤35 samples and 100% (95%CI: 0.92-1.00) for the Ct ≤40 samples. The developed simple, rapid, low-cost, and laboratory-free multiplex LAMP system for the two major important respiratory viral diseases, COVID-19 and influenza, is a promising field-deployable diagnosis tool for the possible future 'twindemic, ' especially in resource-limited settings.
Subject(s)
COVID-19 , Orthomyxoviridae , Humans , SARS-CoV-2/genetics , COVID-19/diagnosis , Sensitivity and Specificity , Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods , DNA , RNA, Viral/analysisABSTRACT
Emerging evidences have shown the utility of saliva for the detection of SARS-CoV-2 by PCR as alternative to nasopharyngeal swab (NPS). However, conflicting results have been reported regarding viral loads between NPS and saliva. We conducted a study to compare the viral loads between NPS and saliva in 42 COVID-19 patients. Viral loads were estimated by the cycle threshold (Ct) values. SARS-CoV-2 was detected in 34 (81%) using NPS with median Ct value of 27.4, and 38 (90%) using saliva with median Ct value of 28.9 (P = 0.79). Kendall's W was 0.82, showing a high degree of agreement, indicating equivalent viral loads in NPS and saliva. After symptom onset, the Ct values of both NPS and saliva continued to increase over time, with no substantial difference. Self-collected saliva has a detection sensitivity comparable to that of NPS and is a useful diagnostic tool with mitigating uncomfortable process and the risk of aerosol transmission to healthcare workers.
Subject(s)
COVID-19/virology , SARS-CoV-2/genetics , Adult , COVID-19/diagnosis , COVID-19 Testing/methods , Diagnostic Tests, Routine/methods , Female , Humans , Male , Middle Aged , Nasopharynx/virology , Polymerase Chain Reaction/methods , RNA, Viral/genetics , SARS-CoV-2/isolation & purification , Saliva/virology , Specimen Handling/methods , Viral Load/methodsABSTRACT
The coronavirus disease 2019 (COVID-19) pandemic has become an urgent global health issue. An older age and underlying conditions, such as diabetes, have been reported as risk factors, but whether or not autoimmune diseases increase the risk remains unknown. An 85-year-old man with Sjögren's syndrome developed a severe COVID-19 infection that required oxygen supplementation. After discussing the goals of care with him and his wife, off-label tocilizumab was given concomitantly, resulting in a rapid improvement in his symptoms and respiratory failure. This patient represents a supplementary case confirming the efficacy and safety of tocilizumab for COVID-19 in elderly patients with autoimmune diseases.
Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , COVID-19/complications , Off-Label Use , Respiratory Distress Syndrome/drug therapy , Sjogren's Syndrome/complications , Adrenal Cortex Hormones/therapeutic use , Aged, 80 and over , Anti-Inflammatory Agents/therapeutic use , COVID-19/immunology , Cytokine Release Syndrome , Drug Therapy, Combination , Dyspnea/etiology , Humans , Male , Pandemics , Respiratory Distress Syndrome/etiology , Respiratory Insufficiency/drug therapy , SARS-CoV-2ABSTRACT
The ongoing spread of coronavirus disease (COVID-19) is a worldwide crisis. Hokkaido Prefecture in Japan promptly declared a state of emergency following the rapid increase of COVID-19 cases, and the policy became an example to mitigate the spread of COVID-19. We herein report 15 cases of COVID-19 including 3 cases requiring mechanical ventilation. Based on review of our cases, among patients over 50 years of age with underlying diseases such as hypertension and diabetes mellitus, and those who required oxygen administration tended to deteriorate. These cases highlight the importance of understanding the background and clinical course of severe cases to predict prognosis.