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Wastewater-based surveillance of the COVID-19 pandemic holds great promise; however, a point-of-use detection method for SARS-CoV-2 in wastewater is lacking. Here, a portable paper device based on CRISPR/Cas12a and reverse-transcription loop-mediated isothermal amplification (RT-LAMP) with excellent sensitivity and specificity was developed for SARS-CoV-2 detection in wastewater. Three primer sets of RT-LAMP and guide RNAs (gRNAs) that could lead Cas12a to recognize target genes via base pairing were used to perform the high-fidelity RT-LAMP to detect the N, E, and S genes of SARS-CoV-2. Due to the trans-cleavage activity of CRISPR/Cas12a after high-fidelity amplicon recognition, carboxyfluorescein-ssDNA-Black Hole Quencher-1 and carboxyfluorescein-ssDNA-biotin probes were adopted to realize different visualization pathways via a fluorescence or lateral flow analysis, respectively. The reactions were integrated into a paper device for simultaneously detecting the N, E, and S genes with limits of detection (LODs) of 25, 310, and 10 copies/mL, respectively. The device achieved a semiquantitative analysis from 0 to 310 copies/mL due to the different LODs of the three genes. Blind experiments demonstrated that the device was suitable for wastewater analysis with 97.7% sensitivity and 82% semiquantitative accuracy. This is the first semiquantitative endpoint detection of SARS-CoV-2 in wastewater via different LODs, demonstrating a promising point-of-use method for wastewater-based surveillance.

Background: The 2019 novel coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 virus (SARS-CoV-2) is a current worldwide threat for which the immunological features after infection need to be investigated. The aim of this study was to establish a highly sensitive and quantitative detection method for SARS-CoV-2 IgG antibody and to compare the antibody reaction difference in patients with different disease severity. Results: Recombinant SARS-CoV-2 nucleocapsid protein was expressed in Escherichia coli and purified to establish an indirect IgG ELISA detection system. The sensitivity of the ELISA was 100% with a specificity of 96.8% and a 98.3% concordance when compared to a colloidal gold kit, in addition, the sensitivity of the ELISA was 100% with a specificity of 98.9% and a 99.4% concordance when compared to a SARS-CoV-2 spike S1 protein IgG antibody ELISA kit. The increased sensitivity resulted in a higher rate of IgG antibody detection for COVID-19 patients. Moreover, the quantitative detection can be conducted with a much higher serum dilution (1:400 vs 1:10, 1:400 vs 1:100). The antibody titers of 88 patients with differing COVID-19 severity at their early convalescence ranged from 800 to 102,400, and the geometric mean titer for severe and critical cases, moderate cases, asymptomatic and mild cases was 51,203, 20,912, and 9590 respectively. Conclusion: The development of a highly sensitive ELISA system for the detection of SARS-CoV-2 IgG antibodies is described herein. This system enabled a quantitative study of rSARS-CoV-2-N IgG antibody titers in COVID-19 patients, the occurrence of higher IgG antibody titers were found to be correlated with more severe cases. [ABSTRACT FROM AUTHOR]

Background: Previous studies have focused on the clinical characteristics of hospitalized patients with the novel 2019 coronavirus disease (COVID-19). Limited data are available for convalescent patients. This study aimed to evaluate the clinical characteristics of discharged COVID-19 patients.Methods: In this retrospective study, we extracted data for 134 convalescent patients with COVID-19 in Guizhou Provincial Staff Hospital from February 15 to March 31, 2020. Cases were analyzed on the basis of demographic, clinical, and laboratory data as well as radiological features.Results: Of 134 convalescent patients with COVID-19, 19 (14.2%) were severe cases, while 115 (85.8%) were non-severe cases. The median patient age was 33 years (IQR, 21.8 to 46.3), and the cohort included 69 men and 65 women. Compared with non-severe cases, severe patients were older and had more chronic comorbidities, especially hypertension, diabetes, and thyroid disease (P < 0.05). Leukopenia was present in 32.1% of the convalescent patients and lymphocytopenia was present in 6.7%, both of which were more common in severe patients. 48 (35.8%) of discharged patients had elevated levels of alanine aminotransferase, which was more common in adults than in children (40.2% vs 13.6%, P = 0.018). A normal chest CT was found in 61 (45.5%) patients during rehabilitation. Severe patients had more ground-glass opacity, bilateral patchy shadowing, and fibrosis. No significant differences were observed in the positive rate of IgG and/or IgM antibodies between severe and non-severe patients.Conclusion: Leukopenia, lymphopenia, ground-glass opacity, and fibrosis are common in discharged severe COVID-19 patients, and liver injury is common in discharged adult patients. We suggest physicians develop follow-up treatment plans based on the different clinical characteristics of convalescent patients. [ABSTRACT FROM AUTHOR]

Objective: Presentation of a case illustrating the benefits of traditional Chinese medicine (TCM) for treatment of Coronavirus disease 2019 (COVID-19) in critically ill patients.Clinical Features and Outcome: A 58-year-old woman presented with cough, fever, dizziness, chest tightness, polypnea and poor appetite. She was admitted to Guizhou Provincial People's hospital, and diagnosed with critically ill type of COVID-19 in February 2020. According to the patient's symptoms and signs, the TCM syndrome differentiation was qi deficiency, dampness-stasis and toxin accumulation. Then she received the combined therapy of a modified Chinese herbal formula and Western medicine. During a twelve-day period of treatment, her respiratory distress and appetite quickly improved. Abnormal laboratory indicators were resumed in time and lung lesions in CT scan largely absorbed. No side effects associated with this Chinese herbal formula were found. Before discharge, two consecutive nasopharyngeal swabs were shown to be negative for severe acute respiratory coronavirus 2 (SARS-CoV-2).Conclusions: Our case report suggests that collaborative treatments with traditional Chinese medicine prove beneficial in the management of COVID-19 in critically ill patients. In order to give optimal care for this COVID-19 crisis for the whole world, Chinese medicine practitioners and Western medical doctors should work together in frontline. [ABSTRACT FROM AUTHOR]

• Many severe COVID-19 patients require intensive care or even mechanical ventilation for those with respiratory failure. • Clinical course of a COVID-19 patient with persistent diarrhoea, acute respiratory failure and shock 1 day after admission. • The patient was undoubtedly classified into the severe type of COVID-19. • Patient recovered promptly after plasma exchange (PE) followed by IVIg, without mechanical ventilation or intensive care. • Timely initiation of PE followed by IVIg in severe COVID-19 patients may improve poor clinical outcomes of these patients. Here we report a case of a laboratory-confirmed 2019 novel coronavirus (2019-nCoV)-infected patient with COVID-19 (coronavirus disease 2019) who developed respiratory failure and shock accompanied by persistent diarrhoea despite conventional therapeutic interventions. The patient avoided mechanical ventilation and showed an immediate clinical and radiological improvement following treatment with intensive plasma exchange (PE) followed by intravenous immunoglobulin (IVIG). Successful therapeutic strategies in this case suggest that timely initiation of PE treatment followed by IVIG in critically ill patients with COVID-19 may prevent the disease from worsening and help to reduce the requirement for mechanical ventilation and intensive supportive care. Moreover, it may improve poor clinical outcomes of these patients. [ABSTRACT FROM AUTHOR]