Establishment of a nucleic acid dipstick test for detection of Schistosoma japonicum specific gene fragments based on the recombinase-aided isothermal amplification assay / 中国血吸虫病防治杂志

Objective To develop a rapid test for detection of Schistosoma japonicum specific gene fragments based on the recombinase-aided isothermal amplification assay (RAA) and nucleic acid dipstick test. Methods The S. japonicum SjG28 gene fragment was selected as the target gene fragment, and the primers and fluorescent probe were designed and synthesized. Then, a S. japonicum nucleic acid dipstick test was established. The sensitivity of this dipstick test was evaluated by detecting different copies of recombinant plasmids containing the S. japonicum SjG28 gene fragment and different concentrations of genomic DNA from adult worms of S. japonicum, and the specificity of the dipstick test was evaluated by detecting the genomic DNA from Clonorchis sinensis, S. mansoni, Ancylostoma duodenale, S. haematobium, Babesia and Paragonimus westermani. Results The S. japonicum nucleic acid dipstick test based on the S. japonicum SjG28 gene fragment showed the minimum detectable limit of 10 copies/μL of the recombinant plasmid containing the S. japonicum SjG28 gene fragment and the minimum detectable limit of 1 pg/μL of S. japonicum genomic DNA, and the dipstick assay tested negative for the genomic DNA from C. sinensis, S. mansoni, A. duodenale, S. haematobium, Babesia and P. westermani. Conclusion A rapid, simple, and visualized assay is established for detection of S. japonicum specific gene fragments based on RAA and nucleic acid dipstick test.

Dipstick urine analysis for detection of renal abnormalities among school children

Background: Urine analysis by dipstick is a useful tool to identify children with asymptomatic renal diseases.  Dipstick urinalysis screening was conducted in asymptomatic school children to detect prevalence of renal disease.Methods: A cross sectional study was carried out in 862 children of age 6 to 15 years studying in different schools of Birgunj, Nepal between January 2019 to June 2019. First morning mid-stream urine samples were obtained from students and tested by dipstick method. Children with abnormal findings were re-tested after fifteen days.Results: Ninety-six (11.13%) children had urinary abnormalities at the first screening; 8 children had specific urinary abnormalities after second screening. 4 children had urinary tract infection, followed by glomerulonephritis, type 1 diabetes, hydronephrosis and nephrotic syndrome. Urinary abnormalities were more common in females than in males.Conclusions: Asymptomatic urinary abnormalities are detected by urine screening program at school age. Further work-up reveals the specific diagnosis and effective interventions help reduce the renal disease in future.

Accuracy of automated urine dipstick test as a screening tool for proteinuria in hypertensive disorders of pregnancy

Background: Progressive proteinuria implies worsening of the condition in hypertensive disorders of pregnancy and hence its quantification guides clinician in making decision and planning treatment. The gold standard is 24 hour urine protein estimation. Urine sediment cytology, also known as ‘liquid renal biopsy’ identifies and analyses the extent of renal damage.Methods: Objectives of the study were to compare the efficacy of urine dipstick test to 24 hour urine protein estimation in detecting proteinuria in pre-eclampsic patients and to describe the findings in urine sediment examination in assessing proteinuria in above patients. Urine dipstick test and sediment cytology were performed on the urinary samples of 242 pregnant women with high BP recordings (BP>140/90 mm Hg) which were collected and tested in Department of Pathology, Government Medical College, Kottayam during the study period of 18 months. This was compared with 24 hour urine protein values (gold standard).Results: About 154 patients (63.63%) had significant proteinuria of more than 300mg/24hr. Dipstick method showed 78.57% sensitivity and 81.82% specificity for prediction of significant proteinuria. Positive predictive value and negative predictive value of urine dipstick test were 88.32% and 68.57% respectively. Urine sediment examination revealed the presence of casts only in 11.98% of study population. Conclusions: Diagnostic accuracy of automated urine dipstick test in assessing proteinuria was 79.75%. For grade 1 proteinuria, diagnostic accuracy was 79.81%, for Grade 2 it increased to 93.14% and for grade 3 & 4, accuracy was 98.68%. Urine sediment examination didn’t correlate with proteinuria and hence the extent of renal damage in pre-eclampsia.

Evaluation of Various Non Culture Methods for the Diagnosis of Spontaneous Bacterial Peritonitis

Introduction: Spontaneous Bacterial Peritonitis (SBP) iscommon and serious complication of patients with livercirrhosis and ascites, without an apparent surgically treatableintra abdominal source of infection. Its prevalence rangesfrom 10% to 30%. Mortality rate was earlier reported morethan 90%, but it has now reduced to 30% -50% as a resultof rapid diagnosis and prompt initiation of antibiotics. Thepresent study was done to evaluate the various non culturemethods for the diagnosis of SBP.Material and Methods: Ascitic fluid sample were collectedaseptically from 100 cirrhotic patients with ascites. PMN(polymorphonuclear leukocyte) count was determined byNeubauer’s manual counting chamber and Leishman’s stainfor differential PMN cell counts. Granulocyte esterase activitywas detected using LER (Leukocyte esterase reagent) dipstickstrips.Results: Out of 100 samples processed, PMN cell count >250 cells/mm3 was found in 91% samples by conventionallight microscopy. Scale of > 2+ by LER strip was found in61 samples. Reading of PMN cell count of > 250 cells/mm3matched in 60 samples and < 250 cells/mm3 matched in 8 cellsby both microscopy and LER strip test. Sensitivity, specificity,positive predictive value and negative predictive value ofLER strip test was 65.9%, 88.89%, 98.36% and 20.51%respectively.Conclusion: LER strips as a screening tool for SBP haveadvantage of speed, low cost, availability at odd hours, requiresno technical expertise and can be performed everywhere.Its high specificity and PPV may help in early institution ofempirical antibiotic therapy in patients.

Diagnostic efficacy of urine dipstick in detecting chronic kidney disease

Background: Proponents of routine urine dipstick screening to identify patients at risk for ESRD in the primary care setting have argued that urine dipsticks are inexpensive, low risk, acceptable to patients, and now, more accurate. Proponents believe that urine dipstick screening has the potential to improve outcomes for people with early disease and increase awareness of CKD. Most primary care physicians agree that populations who are at high risk for CKD should be tested and appropriately treated to decrease complications of ESRD. However, proponents of mass screening may not appreciate the challenges, limitations, and potential harms of screening. Urine dipstick testing does not meet all of the criteria for a good screening test. The aim of the study: To elucidate the diagnostic efficacy of the urine dipstick in detecting chronic kidney disease by assessing its validity as a screening test for detecting CKD. Materials and methods: A community-based cross-sectional study was conducted among 287 subjects aged 20 years and above residing in the P.K. Garden area of Chennai during November 2018 to January 2019. Subjects were interviewed with a questionnaire and blood samples were collected to estimate serum creatinine and a urine sample was collected to estimate the proteinuria using urine S. Thirumavalavan, Noormohamed, Balaji S.M., R Vijaya Kumar. Diagnostic efficacy of urine dipstick in detecting chronic kidney disease. IAIM, 2019; 6(3): 137-142. Page 138 dipstick. eGFR was calculated using CKD – EPI equation and CKD was diagnosed using KDOQI CKD guidelines. Results: The prevalence of Chronic Kidney Disease (<60 ml/min eGFR) in the study group was 10.45%. The Area under Curve (AUC) of the ROC curve for urine dipstick in detecting CKD was 0.948 (0.900 – 0.996) and the 2+ proteinuria was closest to the ideal test point. When proteinuria criteria set at dipstick 2+ or more, the sensitivity was 83.33% and specificity was 98.36%, positive predictive value was 83.33% and κ coefficient of agreement of proteinuria with CKD was 0.81. Conclusion: The urine dipstick test can be used as an effective screening tool in detecting CKD in primary care level. Non Communicable Diseases screening at primary health care level should include the screening of proteinuria using urine dipstick especially for people with risk factors like Diabetes and Hypertension.

Development of an Internally Controlled Reverse Transcription Recombinase-aided Amplification Assay for the Rapid and Visual Detection of West Nile Virus / 生物医学与环境科学（英文）

West Nile virus (WNV) causes West Nile fever and West Nile encephalitis. Because infection by WNV creates serious public health problems, its simple, rapid, and visual detection is very important in clinical practice, especially in resource-limited laboratories. We have developed a rapid, specific, and highly sensitive internally controlled reverse transcription recombinase-aided amplification (RTRAA) assay to detect WNV, using both real-time fluorescence and the lateral flow dipstick (LFD) at 39.0 °C for 30 min. The analytical sensitivity of the RT-RAA assay was 10 plasmid copies and 1.6 pfu per reaction with real-time fluorescence, and 1,000 plasmid copies per reaction with the LFD. No crossreaction with other control viruses was observed. Compared with the RT-qPCR assay, the RT-RAA assay demonstrated 100% sensitivity and 100% specificity for WNV.

Rapid visual detection of Mycobacterium avium subsp. paratuberculosis by recombinase polymerase amplification combined with a lateral flow dipstick

Paratuberculosis (Johne's disease) is a chronic debilitating disease of domestic and wild ruminants. However, widespread point-of-care testing is infrequent due to the lack of a robust method. The isothermal recombinase polymerase amplification (RPA) technique has applied for rapid diagnosis. Herein, RPA combined with a lateral flow dipstick (LFD) assay was developed to estimate DNA from Mycobacterium avium subsp. paratuberculosis. First, analytical specificity and sensitivity of the RPA-nfo primer and probe sets were assessed. The assay successfully detected M. paratuberculosis DNA in 30 min at 39℃ with a detection limit of up to eight copies per reaction, which was equivalent to that of the real-time quantitative polymerase chain reaction (qPCR) assay. The assay was specific, as it did not amplify genomes from five other Mycobacterium spp. or five pathogenic enteric bacteria. Six hundred-twelve clinical samples (320 fecal and 292 serum) were assessed by RPA-LFD, qPCR, and enzyme-linked immunosorbent assay, respectively. The RPA-LFD assay yielded 100% sensitivity, 97.63% specificity, and 98.44% concordance rate with the qPCR results. This is the first report utilizing an RPA-LFD assay to visualize and rapidly detect M. paratuberculosis. Our results show this assay should be a useful method for the diagnosis of paratuberculosis in resource-constrained settings.

Resultados de urocultivos en adultos realizados por el laboratorio de microbiología del Hospital de Clínicas - San Lorenzo de enero del 2015 a agosto de 2016 y métodos de estudio de las infecciones urinarias disponibles en la institución / Results of urine culture in adults carried out by the microbiology laboratory of the Clinics Hospital - San Lorenzo from january 2015 to august 2016 and methods of study of urinary infections available in the institution

Introducción: Los objetivos de este trabajo son: presentar los métodos de estudio de las infecciones urinarias actualmente disponibles en el Laboratorio de Microbiología del Hospital de Clínicas y mostrar los datos de los urocultivos evaluados en forma retrospectiva. Materiales y Métodos: Para estudiar los métodos de estudio de los urocultivos disponibles en el Laboratorio hemos recurrido al archivo del Laboratorio cuyos datos fueron consecutivamente cargados en una planilla de procesamiento de datos Excel de Microsoft Office ®. Los resultados de los urocultivos fueron evaluados de enero de 2015 a agosto de 2016, en forma retrospectiva, observacional, en corte transverso, de los adultos de ambos sexos. Las muestras para urocultivo son recibidas y procesadas en el laboratorio, siguiendo pasos preestablecidos. Resultados: El microorganismo preponderante de los urocultivos fue Escherichia coli (60% de las mujeres y 32% de los varones) seguido por Klebsiella pneumoniae (19% de los varones, 14% de las mujeres). Otros microorganismos aislados fueron Candida sp., Enterococcus faecalis, Enterobacter cloacae, Pseudomona aeruginosa, Proteus mirabilis, Staphylococcus aureus, Acinetobacter baumanii. La resistencia de Escherichia Coli a nitrofurantoína fue del 6% en los varones y 1% en las mujeres. La resistencia de E.Coli a meropenen fue también escasa. En cuanto a Klebsiella pneumoniae en las mujeres, la resistencia fue del 3%. En los hombres, los antibióticos testados para Klebsiella pneumoniae mostraron una resistencia superior al 30%, con excepción del meropenem. Uropatógenos productores de betalactamas de espectro extentido (BLEE) y de carbapenemasas fueron detectados en el presente estudio. Discusión: La toma de la orina para el urocultivo se efectúa siguiendo pautas claras, emanadas del laboratorio. Con la utilización de medios actualmente disponibles en el laboratorio, es posible tipificar el género y la especie tanto de bacterias Gram negativas y positivas como de hongos. Conclusión: La estructura del Laboratorio de Microbiología ha tenido avances que permiten la identificación precisa de los gérmenes de los urocultivos, así como la prevalencia y la resistencia que presentan a ciertos antibióticos. Estos aportes son particularmente útiles para los casos de Escherichia coli y Klebsiella pneumoniae debido a su alta prevalencia. También fue factible constatar la emergencia de gérmenes productores de betalactamasas de espectro extendido (BLEE) y carbapenemasas.

Introduction: The objectives of this work are: to present the methods of study of urinary infections currently available in the Laboratory of Microbiology of the Hospital de Clínicas and to show the data of the urine cultures evaluated retrospectively. Material and method: in order to study the available methods in urine cultures in the Laboratory, we have used the laboratory file whose data were consecutively loaded in an Excel data processing form of Microsoft Office ®. The results of the urine cultures were evaluated from January 2015 to August 2016, in a retrospective, observational, cross-sectional study of adults of both sexes. Samples for urine culture are received and processed in the laboratory, following pre-established steps. Results: The predominant microorganisms were Escherichia coli in 60% of women and 32%of men, Klebsiella pneumonia 19% of men and 14% of women. Other isolated organisms were Candida sp., Enterococcus faecalis, Enterobacter cloacae, Pseudomonas aeruginosa, Proteus mirabilis, Staphylococcus aureus, and Acinetobacter baumanii. Escherichia coli resistance to nitrofurantoin was seen in 6% of men and 1% of women and meropenem resistance to E. coli was also low. As for Klebsiella pneumoniae in women, resistance to meropenem was seen in 3% of cases. In men, the antibiotics tested for Klebsiella pneumoniae showed resistance greater than 30% except for meropenem. Uropathogens producing Extended-Spectrum -lactamase (ESBL ) and Carbapenemase were found. Discussion: Urine collection for urine culture is done following clear guidelines emanating from the laboratory. With the use of media currently available in the laboratory, it is possible to typify the genus and species of both Gram negative and positive bacteria as well as fungi. Conclusion: The structure of the Laboratory of Microbiology has had advances that allow the precise identification of the germs of the urine cultures, as well as the prevalence and resistance to certain antibiotics. These contributions are particularly useful for the cases of Escherichia coli and Klebsiella pneumoniae due to their high prevalence. It was also possible to verify the emergence of spread spectrum beta-lactamases (ESBL) and carbapenemases.

Rapid detection of human adenovirus by recombinase polymerase amplification assay and lateral flow dipstick / 中华实验和临床病毒学杂志

Objective@#To establish a rapid and sensitive isothermal amplification assay for the detection of human Adenovirus.@*Methods@#Primers and probe used for recombinase polymerase amplification(RPA)were designed based on the conserved region of the adenoviruses hexon gene. After optimizing the reaction temperature and times, the products of RPA were detected by capillary electrophoresis and lateral flow dipstick(LFD). Sensitivity and specicity of the assay were evaluated. The diagnostic value of the RPA-LFD assay was verified using clinical samples which were simultaneously tested by real time PCR assay.@*Results@#The analytical sensitivity of RPA-LFD assay was 2 copies DNA molecules per reaction and no cross reaction with other pathogens was observed. Compared with real-time PCR assay, the sensitivity, and specificity of the present assay were all 100%.@*Conclusions@#The RPA-LFD assay developed in this study has the characteristics of high specificity, sensitivity, rapid and no requirement of expensive equipment which provided a new tool for rapid detection of human adenovirus.

Recombinase polymerase amplification combined with a lateral flow dipstick for rapid and visual detection of adenovirus / 军事医学

Objective To develop a rapid, accurate, visual, and portable detection method for adenovirus types B (AdvB) and E ( AdvE).Methods Universal primers were targeted on type-specific conserved regions to allow the simultaneous detection of both human Adv (HAdV) species.A detection method based on the combination of recombinase polymerase amplification ( RPA) and lateral flow dipstick ( LFD) was established the sensitivity and specificity evaluated , and throat swab specimens of 19 patients infected with AdvB and AdvE as well as 10 healthy volunteers were detected with this method.Results The detection limit of the method was 10 copies/μl Adv DNA, which was close to that of qPCR , and there were no cross-reactions with other species of Adv and unrelated virus .The detection could be finished within 15 to 20 min within the temperature range of 25 to 45℃.When applied to clinical samples , this method showed 100% sensitivity and specificity.Conclusion This detection assay is a sensitive , specific, rapid and simple method that eliminates the need for expensive equipment , trained personnel or laboratories .The characteristics of this system render it suitable for use in grass-roots healthcare departments , and the system is especially effective for field testing and on-site testing.

Recombinase polymerase amplification combined with a lateral flow dipstick for rapid and visual detection of adenovirus / 军事医学

Objective To develop a rapid, accurate, visual, and portable detection method for adenovirus types B (AdvB) and E ( AdvE).Methods Universal primers were targeted on type-specific conserved regions to allow the simultaneous detection of both human Adv (HAdV) species.A detection method based on the combination of recombinase polymerase amplification ( RPA) and lateral flow dipstick ( LFD) was established the sensitivity and specificity evaluated , and throat swab specimens of 19 patients infected with AdvB and AdvE as well as 10 healthy volunteers were detected with this method.Results The detection limit of the method was 10 copies/μl Adv DNA, which was close to that of qPCR , and there were no cross-reactions with other species of Adv and unrelated virus .The detection could be finished within 15 to 20 min within the temperature range of 25 to 45℃.When applied to clinical samples , this method showed 100% sensitivity and specificity.Conclusion This detection assay is a sensitive , specific, rapid and simple method that eliminates the need for expensive equipment , trained personnel or laboratories .The characteristics of this system render it suitable for use in grass-roots healthcare departments , and the system is especially effective for field testing and on-site testing.

Impact of random urine proteinuria on maternal and fetal outcomes of pregnancy: a retrospective case-control study

BACKGROUND/AIMS: Proteinuria is associated with hypertension and preeclampsia in pregnancy. However, the impact of random urine proteinuria on fetal and maternal outcomes has not been established. We investigated the influence of random urine proteinuria on the clinical outcomes of pregnancy. METHODS: From January 2008 to December 2010, 2,822 patients were retrospectively studied. A total of 536 pregnant women with proteinuria in random urine and matched controls without proteinuria via propensity score matching were analyzed. Proteinuria was checked by the dipstick method. RESULTS: The patients’ mean age was 33.0 ± 4.7 years, and the mean gestational age was 235.6 ± 50.6 days on admission. The prevalence of hypertension and chronic kidney disease was 2.4% (n = 67) and 1.0% (n = 29), respectively. Women with random urine proteinuria showed higher blood urea nitrogen levels and a higher incidence of hematuria. These women also had a higher incidence of preeclampsia, preterm labor, premature rupture of membranes, and intrauterine growth restriction. Proteinuria was strongly correlated with preeclampsia in both propensity score matching (p < 0.001, r = 0.783) and unmatched whole samples (p < 0.001, r = 0.851). CONCLUSIONS: These findings suggest that random urine proteinuria is associated with preeclampsia, preterm labor, premature rupture of membrane, and intrauterine growth restriction.

Serological diagnosis methods of schistosomiasis japonica at different preva-lence:a meta-analysis / 中国血吸虫病防治杂志

Objective To comprehensively evaluate the effects of indirect hemagglutination test(IHA),enzyme?linked im?munosorbent assay(ELISA),and dipstick dye method(DDIA)in the diagnosis of schistosomiasis japonica at different preva?lence by using Meta?analysis. Methods Through the literature review according to the inclusion and exclusion criteria,a data?base was established,and by using Meta?disc and R software,the Meta?analysis was performed including the threshold test,het?erogeneity test,weighted by the quantitative effect of merger,SROC curve fitting,etc. Results A total of 60 papers were in?cluded in the final analysis. The sensitivities of IHA were 0.84,0.76 and 0.94 in heavy,medium and low endemic areas,and specificities were 0.73,0.64 and 0.73 respectively;the sensitivities of ELISA were 0.88,0.80 and 0.93 in heavy,medium and low endemic areas,and the specificities were 0.59,0.59 and 0.62 respectively;the sensitivities of DDIA were 0.93,0.81 and 0.93 in the heavy,medium and low endemic areas,and specificities were 0.66,0.69 and 0.59 respectively. The weighted sensi?tivities of IHA,ELISA and DDIA were 0.83,0.87 and 0.90 respectively;the weighted specificities were 0.69,0.60 and 0.62 re?spectively. The areas under the curve of SROC were 0.89,0.96 and 0.92 in IHA,ELISA and DDIA respectively. Conclusions In different prevalence,the effectiveness of different methods for serological diagnosis of schistosomiasis is different. The sensi?tivity and specificity of all diagnostic methods of schistosomiasis need to further improve.

Correlation of Nitrite, Leucocyte Esterase and Protein Detection to Diagnosis of Urinary Tract Infections.

Aim: To determine the relationship between detection of nitrite, Leucocyte esterase (LE) and protein in urine and significant bacteriuria. Study Design: Cross-sectional descriptive study. Place and Duration of Study: Department of Medical Microbiology and Parasitology, University of Port Harcourt Teaching Hospital, between March and September 2015. Methodology: 240 urine samples were analyzed. Dipstick analysis using Combi-UriScreen 10SL reagent strips (Axiom Medical limited, UK) and culture for significant bacteriuria were performed according to manufacturer’s instruction/ using standard protocols. Data was coded, entered into Microsoft Excel ® version 2010 and analysed using Epi-Info version 7.02. Categorical data were presented as frequencies and percentages using tables. Univariate analysis using logistic regression (Odds Ratio) was used to determine the association between the presence of nitrite, LE and protein and significant bacterial yield in urine. A P-value of ≤ 0.05 was considered statistically significant. Likelihood ratios were calculated. Results: 23 (23.2%) out of 99 samples with significant bacteriuria were nitrite positive, while 42 (42.4%) and 45 (45.5%) were positive for leucocyte esterase and protein respectively. Nitrite (P = 0.001, OR = 5.03, 95% CI = 2.02-12.93) and leucocyte esterase positivity (P = 0.001, OR = 3.59, 95% CI = 1.91-6.80) were significantly associated with significant bacteriuria while proteinuria was not (P = 0.989, OR = 1.03, 95% CI = 0.60-1.79). Nitrite positivity alone had the best positive likelihood ratio (4.09, 95% CI: 1.91, 8.78) followed by the combination of nitrite and LE positivity (3.65, 95% CI: 1.90, 7.03). Conclusion: The use of dipstick analysis of urine as a screening tool for samples to be cultured may be a very effective way of reducing laboratory costs and wastage of man hours, which both ultimately improve the effectiveness of clinical laboratories especially in resource-poor settings.

Comparison of Urinary Protein Creatinine Index (uPCI) and Dipsticks for the Prediction of Renal Dysfunction in Chronic Cigarette Smokers.

Background: Proteinuria is recognized as one of the earliest sign of renal function deterioration in chronic smokers. Proteinuria occurs due to alteration in glomerular permeability and later due to failure of reabsorption of filtered protein by the tubular cells. Normally, most healthy adults excrete 20 – 150 mg of protein in urine over 24 hours. However, it is difficult to collect 24 hrs urine samples. Objectives: To advocate the use of PCI (protein creatinine index) in assessment of proteinuria and to compare dipstick result with PCI in the assessment of proteinuria in chronic cigarette smokers. Material & Methods: A total of 30 cigarette smokers and 40 age and sex matched controls were included for the study. A random specimen of urine collected from each cigarette smoker and non- smoker was tested quantitatively by manual sulfosalicylic acid colorimetric method for the estimation of protein concentration. Creatinine concentration in each specimen was measured by modified Jaffe’s method and the urinary PCI was calculated. Results: Normal range of PCI which has been established in this study is 50 to 259. Significantly higher amounts of protein were found to be excreted in urine in chronic smokers (9.313 ± 4.003 mg/dl) as compared to healthy non smokers (7.738 ± 2.05 mg/dl). On comparison of PCI between healthy non smoker and chronic smoker subjects, PCI has been found to be significantly elevated in chronic smokers (healthy non smoker- 118.32 ± 56.86, chronic smoker- 180.1 ± 88.23) (p=0.001). Conclusion: PCI of random urine sample can provide a very useful, simple and convenient method for the quantitative assessment of proteinuria to confirm the advent of kidney damage, avoiding the drawbacks of 24 hrs urine collection.

Advances in recombinase polymerase amplification / 军事医学

Recombinase polymerase amplification (RPA) is a novel isothermal DNA amplification technology first re-ported in 2006 by Piepenburg et al.This technology has been shown to typically work at temperatures ranging from 25 to 43℃and can detect products within 5-20 min.RPA technology requires little instrumentation for the nucleic acid amplifi-cation reaction and can be performed not only in PCR tubes , but also in simple devices′such as paper .Combined with probe-based detection methods or lateral flow dipstick assay , it can perform quantitative or visual detection respectively . RPA is a technology that is potentially ideal for point-of-care diagnosis and disease prevention and control ,characterized by high sensitivity, high efficiency, high specificity and user-friendliness.This paper introduces the advantages and develop-ment of RPA technology in reaction conditions and product detection ,summarizes the current applications of this technolo-gy,and predicts the trend of application of RPA technology in point-of-care diagnosis and disease prevention and control .

Urinary Abnormalities in Asymptomatic Children of Ho Chi Minh City: A Population-Based Study.

Aims: To estimate the prevalence of urinary abnormalities in asymptomatic children aged 3 to 5 and to estimate the prevalence of urological anomalies detected by renal ultrasound among children with abnormal urine findings in an urban district of Ho Chi Minh City. Study Design: cross-sectional population-based study. Place and Duration of Study: Twelve kindergartens in Binh Thanh district, Ho Chi Minh City, Vietnam from March to June 2012. Methodology: There were 11,093 children aged 3 to 5 attending 25 public and 17 private kindergartens including 2,657 in wealthy wards and 8,436 in non-wealthy wards. A total sample size of 2,402 children was required. Using a probability proportional-tosize method, 8 kindergartens in public area and 4 kindergartens in private area were randomly selected. Overall, 2,433 children were enrolled including 1,244 boys. The children were screened by dipstick. Those with abnormal results were confirmed by a second dipstick. Children with two positive dipsticks were retested 3 months later and underwent renal ultrasound for urological anomalies. Results: Abnormalities were detected in 7.8% of the subjects. Prevalence of proteinuria, hematuria, nitrituria, leucocyturia, and combined nitrituria and leucocyturia were 0%, 0.3%, 0%, 5.6%, and 0.2%, respectively. Girls had more abnormal results than boys (14.1% vs 1.8%, p<0.001). After a three-month period, the number of children with persistent abnormalities was 37. The renal ultrasound detected 5 (13.5%) hydronephrosis cases. No significant difference was found when comparing public to private kindergartens and wealthy to non-wealthy region. Conclusion: In such a region with high population density, the high prevalence of nitrituria and/or leucocyturia in girls calls for a good education for parents and caregivers in order to prevent urinary tract infection, and the low prevalence of proteinuria and hematuria suggests that the appropriate age for urinary screening in Vietnam might be over 6 years.

The Clinical Use of Routine Urinalysis

Routine urinalysis is a simple, economical, and useful test that facilitates the detection of urinary system diseases and monitoring of renal disease progression. It consists of 4 parts of specimen evaluation, gross examination, a dipstick urinalysis, and a sediment microscopic urinalysis. Urine specimens should first be evaluated in terms of acceptability, and thereafter, the gross appearance is examined for color, turbidity, and odor. In particular, a dipstick urinalysis is an easy and rapid test that provides information on the multiple physicochemical properties of the urine sample. Moreover, although a sediment microscopic urinalysis is time-consuming, it provides information on the cells, microorganisms, casts, and crystals. In the present report, the clinical significance of the routine urinalysis and the problems concerning interpretation are summarized.

Urinalysis: The Usefulness and Limitations of Urine Dipstick Testing

The urinalysis is an essential part of the diagnostic work-up for kidney disease and other renal system disorders. The dipstick test allows rapid and simultaneous chemical analyses of urine, including factors such as pH, specific gravity, protein, glucose, ketones, occult blood, bilirubin, urobilinogen, nitrite, and leukocyteesterase. The chemical reactions on dipstick are complicated and can be affected by oxidizing, reducing, and discoloring substances in the urine. Therefore, false positive and false negative results are common in dipstick testing. To obtain reliable results with the dipstick, it is necessary to collect urine cleanly and examine the urine carefully. It is mandatory to clearly understand the principles of dipstick testing to evaluate abnormal findings. If the urine dipstick results suggest hematuria, proteinuria, or urinary tract infection, microscopy of the urine should be performed to confirm the findings.

Monoclonal Antibody-Based Dipstick Assay: A Reliable Field Applicable Technique for Diagnosis of Schistosoma mansoni Infection Using Human Serum and Urine Samples

A field applicable diagnostic technique, the dipstick assay, was evaluated for its sensitivity and specificity in diagnosing human Schistosoma mansoni infection. A monoclonal antibody (mAb) against S. mansoni adult worm tegumental antigen (AWTA) was employed in dipstick and sandwich ELISA for detection of circulating schistosome antigen (CSA) in both serum and urine samples. Based on clinical and parasitological examinations, 60 S. mansoni-infected patients, 30 patients infected with parasites other than schistosomiasis, and 30 uninfected healthy individuals were selected. The sensitivity and specificity of dipstick assay in urine samples were 86.7% and 90.0%, respectively, compared to 90.0% sensitivity and 91.7% specificity of sandwich ELISA. In serum samples, the sensitivity and specificity were 88.3% and 91.7% for dipstick assay vs. 91.7% and 95.0% for sandwich ELISA, respectively. The diagnostic efficacy of dipstick assay in urine and serum samples was 88.3% and 90.0%, while it was 90.8% and 93.3% for sandwich ELISA, respectively. The diagnostic indices of dipstick assay and ELISA either in serum or in urine were statistically comparable (P>0.05). In conclusion, the dipstick assay offers an alternative simple, rapid, non-invasive technique in detecting CSA or complement to stool examinations especially in field studies.