BACKGROUND Rapid molecular testing has revolutionized the management of suspected viral meningitis and encephalitis by providing an etiological diagnosis in<90 min with potential to improve outcomes and shorten inp...BACKGROUND Rapid molecular testing has revolutionized the management of suspected viral meningitis and encephalitis by providing an etiological diagnosis in<90 min with potential to improve outcomes and shorten inpatient stays.However,use of molecular assays can vary widely.AIM To evaluate current practice for molecular testing of pediatric cerebrospinal fluid(CSF)samples across the United Kingdom using a structured questionnaire.METHODS A structured telephone questionnaire survey was conducted between July and August 2020.Data was collected on the availability of viral CSF nucleic acid amplification testing(NAAT),criteria used for testing and turnaround times including the impact of the coronavirus disease 2019 pandemic.RESULTS Of 196/212(92%)microbiology laboratories responded;63/196(32%)were excluded from final analysis as they had no on-site microbiology laboratory and outsourced their samples.Of 133 Laboratories included in the study,47/133(35%)had onsite facilities for viral CSF NAAT.Hospitals currently undertaking onsite NAAT(n=47)had much faster turnaround times with 39 centers(83%)providing results in≤24 h as compared to those referring samples to neighboring laboratories(5/86;6%).CONCLUSION Onsite/near-patient rapid NAAT(including polymerase chain reaction)is recommended wherever possible to optimize patient management in the acute setting.展开更多
Hepatitis C virus(HCV)infection represents a significant health problem and represents a heavy load on some countries like Egypt in which about 20%of the total population are infected.Initial infection is usually asym...Hepatitis C virus(HCV)infection represents a significant health problem and represents a heavy load on some countries like Egypt in which about 20%of the total population are infected.Initial infection is usually asymptomatic and result in chronic hepatitis that give rise to complications including cirrhosis and hepatocellular carcinoma.The management of HCV infection should not only be focus on therapy,but also to screen carrier individuals in order to prevent transmission.In the present,molecular detection and quantification of HCV genome by real time polymerase chain reaction(PCR)represent the gold standard in HCV diagnosis and plays a crucial role in the management of therapeutic regimens.However,real time PCR is a complicated approach and of limited distribution.On the other hand,isothermal DNA amplification techniques have been developed and offer molecular diagnosis of infectious dieses at point-of-care.In this review we discuss recombinase polymerase amplification technique and illustrate its diagnostic value over both PCR and other isothermal amplification techniques.展开更多
Enterocytozoon hepatopenaei(EHP)infection has seriously affected prawn culture globally.The symptoms of the infection are not apparent,and traditional detection methods are time consuming and low in accuracy.We develo...Enterocytozoon hepatopenaei(EHP)infection has seriously affected prawn culture globally.The symptoms of the infection are not apparent,and traditional detection methods are time consuming and low in accuracy.We developed a new onsite rapid testing device(size 18.8×16.7×6.6 cm^(3))for EHP based on magnesium pyrophosphate precipitation and facilitated by loop mediated isothermal amplification(LAMP).The design and fabrication of the device enables efficient light absorbance.The device has a highly sensitive detector,high-precision thermal controller,and humanized touch screen.The temperature control precision of the device is 0.2-0.3℃ at 60℃,63℃,and 65℃.The coefficients of variation values(CVV)of the luminous power in one channel at light on and off were found to be 0.0097 and 0.0014,respectively,within 1 h.The CVV of the background,luminous power,and values of eight PCR tubes filled with pure water were all less than 5%.In the EHP experiment,eight samples(including seven positive and one negative)confirmed the effectiveness of the device,and four positive and four negative samples verified whether cross-contamination exists.Among them,the rise time of the curve was about 15 min.These results assert that the developed device exhibits enhanced stability and uniformity and has excellent performance with high sensitivity,good specificity,and low testing time.Moreover,the optimal and minimum absorbance range was 555-655 nm for monitoring the production of LAMP.展开更多
Background:Tuberculosis(TB)remains a major threat to human health,and TB diagnostic methods remain unsatisfactory.Nucleic acid amplification tests(NAATs)show higher sensitivity compared with culture for the diagnosis ...Background:Tuberculosis(TB)remains a major threat to human health,and TB diagnostic methods remain unsatisfactory.Nucleic acid amplification tests(NAATs)show higher sensitivity compared with culture for the diagnosis of pulmonary TB(PTB).However,NAATs are expensive and cannot be easily implemented outside major medical centers.To improve the sensitivity of NAATs for PTB diagnosis,we investigated the predictive factors that might optimize NAAT utilization.Methods:A total of 1263 patients with suspected PTB were enrolled for evaluation.The sensitivity,specificity,and accuracy of methods including smear-microbiology,culture of Mtb and NAAT for Mycobacterium tuberculosis(Mtb)detection in sputum and bronchoalveolar lavage fluid samples were compared.Odds ratios and 95%confidence intervals were used to assess variables that might be associated with positive NAAT results for sputum and bronchoalveolar lavage fluid from patients with suspected PTB.Results:NAAT showed higher sensitivity for Mtb detection(61.1%)when compared with smear(9.0%)and Mtb culture(47.8%).We found that an elevated erythrocyte sedimentation rate,the presence of cavities,and positive interferon-𝛾release assay(IGRA)results were indicative of positive Mtb detection by NAAT.Moreover,individuals who had all three of these characteristics showed an 86%diagnostic positivity for PTB from Mtb detection by NAAT.Conclusions:Our study suggests that an elevated erythrocyte sedimentation rate,a positive IGRA result,and the presence of pulmonary cavities are helpful factors for predicting positive Mtb detection by NAAT.Patients with the three positive clinical markers should undergo NAAT for Mtb detection because they are the most likely individuals to be bacteriologically confirmed as having TB.展开更多
文摘BACKGROUND Rapid molecular testing has revolutionized the management of suspected viral meningitis and encephalitis by providing an etiological diagnosis in<90 min with potential to improve outcomes and shorten inpatient stays.However,use of molecular assays can vary widely.AIM To evaluate current practice for molecular testing of pediatric cerebrospinal fluid(CSF)samples across the United Kingdom using a structured questionnaire.METHODS A structured telephone questionnaire survey was conducted between July and August 2020.Data was collected on the availability of viral CSF nucleic acid amplification testing(NAAT),criteria used for testing and turnaround times including the impact of the coronavirus disease 2019 pandemic.RESULTS Of 196/212(92%)microbiology laboratories responded;63/196(32%)were excluded from final analysis as they had no on-site microbiology laboratory and outsourced their samples.Of 133 Laboratories included in the study,47/133(35%)had onsite facilities for viral CSF NAAT.Hospitals currently undertaking onsite NAAT(n=47)had much faster turnaround times with 39 centers(83%)providing results in≤24 h as compared to those referring samples to neighboring laboratories(5/86;6%).CONCLUSION Onsite/near-patient rapid NAAT(including polymerase chain reaction)is recommended wherever possible to optimize patient management in the acute setting.
文摘Hepatitis C virus(HCV)infection represents a significant health problem and represents a heavy load on some countries like Egypt in which about 20%of the total population are infected.Initial infection is usually asymptomatic and result in chronic hepatitis that give rise to complications including cirrhosis and hepatocellular carcinoma.The management of HCV infection should not only be focus on therapy,but also to screen carrier individuals in order to prevent transmission.In the present,molecular detection and quantification of HCV genome by real time polymerase chain reaction(PCR)represent the gold standard in HCV diagnosis and plays a crucial role in the management of therapeutic regimens.However,real time PCR is a complicated approach and of limited distribution.On the other hand,isothermal DNA amplification techniques have been developed and offer molecular diagnosis of infectious dieses at point-of-care.In this review we discuss recombinase polymerase amplification technique and illustrate its diagnostic value over both PCR and other isothermal amplification techniques.
基金supported by the grant from the National Natural Science Foundation of China(Nos.61901168,61971187,61871180,82002405)Hunan Key Research and Development Program(No.2021SK2003)+1 种基金Zhuzhou Innovative City Construction Project(No.2020-020)China Postdoctoral Science Foundation(No.2018M630498)。
文摘Enterocytozoon hepatopenaei(EHP)infection has seriously affected prawn culture globally.The symptoms of the infection are not apparent,and traditional detection methods are time consuming and low in accuracy.We developed a new onsite rapid testing device(size 18.8×16.7×6.6 cm^(3))for EHP based on magnesium pyrophosphate precipitation and facilitated by loop mediated isothermal amplification(LAMP).The design and fabrication of the device enables efficient light absorbance.The device has a highly sensitive detector,high-precision thermal controller,and humanized touch screen.The temperature control precision of the device is 0.2-0.3℃ at 60℃,63℃,and 65℃.The coefficients of variation values(CVV)of the luminous power in one channel at light on and off were found to be 0.0097 and 0.0014,respectively,within 1 h.The CVV of the background,luminous power,and values of eight PCR tubes filled with pure water were all less than 5%.In the EHP experiment,eight samples(including seven positive and one negative)confirmed the effectiveness of the device,and four positive and four negative samples verified whether cross-contamination exists.Among them,the rise time of the curve was about 15 min.These results assert that the developed device exhibits enhanced stability and uniformity and has excellent performance with high sensitivity,good specificity,and low testing time.Moreover,the optimal and minimum absorbance range was 555-655 nm for monitoring the production of LAMP.
基金This work was supported by the Natural Science Foundation of China(No.81,873,958,81,802,058)the National Key Research and Development Plan(No.2019YFC0840602,2020YFA0907201)+2 种基金the Guang-dong Scientific and Technological Foundation(No.2019B1515120041,2020B1111170014)the Shen-zhen Scientific and Technological Foundation(No.JCYJ20180228162336873,JCYJ20180228162321234,KCXFZ202002011007083)the China Postdoctoral Science Foundation(No.2020M670085ZX).
文摘Background:Tuberculosis(TB)remains a major threat to human health,and TB diagnostic methods remain unsatisfactory.Nucleic acid amplification tests(NAATs)show higher sensitivity compared with culture for the diagnosis of pulmonary TB(PTB).However,NAATs are expensive and cannot be easily implemented outside major medical centers.To improve the sensitivity of NAATs for PTB diagnosis,we investigated the predictive factors that might optimize NAAT utilization.Methods:A total of 1263 patients with suspected PTB were enrolled for evaluation.The sensitivity,specificity,and accuracy of methods including smear-microbiology,culture of Mtb and NAAT for Mycobacterium tuberculosis(Mtb)detection in sputum and bronchoalveolar lavage fluid samples were compared.Odds ratios and 95%confidence intervals were used to assess variables that might be associated with positive NAAT results for sputum and bronchoalveolar lavage fluid from patients with suspected PTB.Results:NAAT showed higher sensitivity for Mtb detection(61.1%)when compared with smear(9.0%)and Mtb culture(47.8%).We found that an elevated erythrocyte sedimentation rate,the presence of cavities,and positive interferon-𝛾release assay(IGRA)results were indicative of positive Mtb detection by NAAT.Moreover,individuals who had all three of these characteristics showed an 86%diagnostic positivity for PTB from Mtb detection by NAAT.Conclusions:Our study suggests that an elevated erythrocyte sedimentation rate,a positive IGRA result,and the presence of pulmonary cavities are helpful factors for predicting positive Mtb detection by NAAT.Patients with the three positive clinical markers should undergo NAAT for Mtb detection because they are the most likely individuals to be bacteriologically confirmed as having TB.
