Rapid detection and genotyping of SARS-CoV-2 Omicron BA.4/5 variants using a RT-PCR and CRISPR-Cas12a-based assay / 南方医科大学学报

OBJECTIVE@#To establish a rapid detection and genotyping method for SARS-CoV-2 Omicron BA.4/5 variants using CRISPPR-Cas12a gene editing technology.@*METHODS@#We combined reverse transcription-polymerase chain reaction (RT-PCR) and CRISPR gene editing technology and designed a specific CRISPPR RNA (crRNA) with suboptimal protospacer adjacent motifs (PAM) for rapid detection and genotyping of SARS- CoV-2 Omicron BA.4/5 variants. The performance of this RT- PCR/ CRISPPR-Cas12a assay was evaluated using 43 clinical samples of patients infected by wild-type SARS-CoV-2 and the Alpha, Beta, Delta, Omicron BA. 1 and BA. 4/5 variants and 20 SARS- CoV- 2-negative clinical samples infected with 11 respiratory pathogens. With Sanger sequencing method as the gold standard, the specificity, sensitivity, concordance (Kappa) and area under the ROC curve (AUC) of RT-PCR/CRISPPR-Cas12a assay were calculated.@*RESULTS@#This assay was capable of rapid and specific detection of SARS- CoV-2 Omicron BA.4/5 variant within 30 min with the lowest detection limit of 10 copies/μL, and no cross-reaction was observed in SARS-CoV-2-negative clinical samples infected with 11 common respiratory pathogens. The two Omicron BA.4/5 specific crRNAs (crRNA-1 and crRNA-2) allowed the assay to accurately distinguish Omicron BA.4/5 from BA.1 sublineage and other major SARS-CoV-2 variants of concern. For detection of SARS-CoV-2 Omicron BA.4/5 variants, the sensitivity of the established assay using crRNA-1 and crRNA-2 was 97.83% and 100% with specificity of 100% and AUC of 0.998 and 1.000, respectively, and their concordance rate with Sanger sequencing method was 92.83% and 96.41%, respectively.@*CONCLUSION@#By combining RT-PCR and CRISPPR-Cas12a gene editing technology, we successfully developed a new method for rapid detection and identification of SARS-CoV-2 Omicron BA.4/5 variants with a high sensitivity, specificity and reproducibility, which allows rapid detection and genotyping of SARS- CoV-2 variants and monitoring of the emerging variants and their dissemination.

The impact of temperature and absolute humidity on the coronavirus disease 2019 (COVID-19) outbreak - evidence from China

OBJECTIVETo investigate the impact of temperature and absolute humidity on the coronavirus disease 2019 (COVID-19) outbreak. DESIGNEcological study. SETTING31 provincial-level regions in mainland China. MAIN OUTCOME MEASURESData on COVID-19 incidence and climate between Jan 20 and Feb 29, 2020. RESULTSThe number of new confirm COVID-19 cases in mainland China peaked on Feb 1, 2020. COVID-19 daily incidence were lowest at -10 {degrees}C and highest at 10 {degrees}C, while the maximum incidence was observed at the absolute humidity of approximately 7 g/m3. COVID-19 incidence changed with temperature as daily incidence decreased when the temperature rose. No significant association between COVID-19 incidence and absolute humidity was observed in distributed lag nonlinear models. Additionally, A modified susceptible-exposed-infectious-recovered (M-SEIR) model confirmed that transmission rate decreased with the increase of temperature, leading to further decrease of infection rate and outbreak scale. CONCLUSIONTemperature is an environmental driver of the COVID-19 outbreak in China. Lower and higher temperatures might be positive to decrease the COVID-19 incidence. M-SEIR models help to better evaluate environmental and social impacts on COVID-19. What is already known on this topicO_LIMany infectious diseases present an environmental pattern in their incidence. C_LIO_LIEnvironmental factors, such as climate and weather condition, could drive the space and time correlations of infectious diseases, including influenza. C_LIO_LISevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be transmitted through aerosols, large droplets, or direct contact with secretions (or fomites) as influenza virus can. C_LIO_LILittle is known about environmental pattern in COVID-19 incidence. C_LI What this study addsO_LIThe significant association between COVID-19 daily incidence and temperature was confirmed, using 3 methods, based on the data on COVID-19 and weather from 31 provincial-level regions in mainland China. C_LIO_LIEnvironmental factors were considered on the basis of SEIR model, and a modified susceptible-exposed-infectious-recovered (M-SEIR) model was developed. C_LIO_LISimulations of the COVID-19 outbreak in Wuhan presented similar effects of temperature on incidence as the incidence decrease with the increase of temperature. C_LI

Progress in serological detection of Zika virus infection / 中华微生物学和免疫学杂志

Zika virus ( ZIKV) infection may lead to some serious potential complications, such as neonatal microcephaly and Guillain-Barre syndrome. ZIKV epidemics have caused public panic and aroused global concern. World Health Organization ( WHO) has listed ZIKV infection as one of the public health emergencies of international concern. This paper focused on the progress in ZIKV detection methods, espe-cially in serological tests, and summarized the advantages and disadvantages of each method in practical ap-plication, aiming to provide technical reference for the prevention and control of Zika virus infection.

Nucleic acid testing for point-of-care using：advances in technologies and future perspectives / 中华检验医学杂志

Point-of-care testing ( POCT ) is expanding rapidly worldwide due to its simplicity and rapid testing.At present , POCT has mainly focused on detection of proteins ( antigen/antibody ) and small molecules based on immunological assay and dry chemical technology.In the past decade , rapid diagnostic assays for nucleic acid have quickly progressed.Some nucleic acid-based POCT products have been developed and approved by US FDA.Now this article discusses the advances in the field of rapid nucleic acid testing including some new technologies and their applications.As a new area of in vitro diagnostics , POCT for nucleic acid is worthy of our attention.

Establishment and performance evaluation of the quantitative detection for procalcitonin based on fluorescence immunochromatography / 中华检验医学杂志

Objective To develop a quick quantitative detecting method for point of care testing (POCT) of human serum procalcitonin (PCT) by fluorescence immunochromatographic technology.Methods Applying a double-antibody sandwich immunofluorescent assay (one antibody coated on the nitrocellulose membrane and the other antibody labeled with fluorescent micropaticles) to develop a PCT quantitative detecting kit by immunochromatography technology.The kit was used to test PCT in 472 serum samples from suspected bacterial infection patients of Guangzhou Red Cross Hospital,including 240 male and 232 female patients.The methodology and diagnostic performance were evaluated in the aspects of linearity,precision,accuracy,specificity,stability experiments and comparison with foreign PCT detecting kits.Results The report range of the PCT quantitative diagnostic kit was 0.1-125.0 μg/L The coefficient of variation (CV)values of repeat 20 tests for low,median,and high concentration control samples respectively were all less than 15％ and bias can be acceptable (P ＞ 0.05).Common interfering substances in human serum specimens such as bilirubin (2.0 g/L),triglyceride (30.0 g/L) and cholesterol (15.0 g/L) were found no significant affect on quantitative detection of PCT.The shelf time of the PCT diagnostic kit should be longer than 12 months as the relative deviation of detected concentrations of 0.5,1.0,22.0,65.0 μg/L PCTcontrol sample can be controlled less than 20％ within 14 months.Considering VIDAS BRAHMS PCT to be the standard quantitative test for PCT,472 serum samples were detected by both our kit and the control VIDAS BRAHMS PCT kit simultaneously,which showed high correlation (YVIDAS =0.180 + 1.006Xwondfo,R2 =0.988,P ＜ 0.01) and low deviation (Z =-1.6,P ＞ 0.05) without statistic significance between two methods.And the results of these two diagnostic kits showed good consistency as the area under curve of the receiver operating characteristic (ROC) of Wondfo-PCT at the three cut-off values (0.5,2.0,10.0 μg/L)were 0.997,0.994,0.998 respectively,P ＜ 0.01,using diagnostic result of the control product as standard.Kappa values were 0.899,0.905,0.973 respectively.Conclusions The method of quantitative detection of PCT by fluorescence immunochromatography for POCT was established in this study.All the observed indicators reached the clinical diagnostic requirements and can be applied for the quick detection of clinical human serum PCT.

Comprehensive Evaluation of Medical Quality with Factor Analysis and Weighted TOPSIS Method / 中国卫生统计

Objective A comprehensive evaluation of the quality of medical service from January to December in 2007 was conducted in order to provide scientific policies for far-flung work and create bigger benefit in a certain hospital. Methods Apply factor analysis ascertains the weight,and we carry through a comprehensive evaluation of the quality of medical service combine with weighted TOPSIS to the hospital. Results The quality of medical service of hospital in 2007. The months of April,July , November better; February,May, October worse. The results accord with reality. Conclusion Research shows comprehensive evaluation of hospital medical quality needs a scientific target system. Using factor analysis and combining weighted TOPSIS in comprehensive evaluation is more objective and more scientific and authentic as take full advantage of the original source.