BACKGROUND Helicobacter pylori(H.pylori)infection has been well-established as a significant risk factor for several gastrointestinal disorders.The urea breath test(UBT)has emerged as a leading non-invasive method for...BACKGROUND Helicobacter pylori(H.pylori)infection has been well-established as a significant risk factor for several gastrointestinal disorders.The urea breath test(UBT)has emerged as a leading non-invasive method for detecting H.pylori.Despite numerous studies confirming its substantial accuracy,the reliability of UBT results is often compromised by inherent limitations.These findings underscore the need for a rigorous statistical synthesis to clarify and reconcile the diagnostic accuracy of the UBT for the diagnosis of H.pylori infection.AIM To determine and compare the diagnostic accuracy of 13C-UBT and 14C-UBT for H.pylori infection in adult patients with dyspepsia.METHODS We conducted an independent search of the PubMed/MEDLINE,EMBASE,and Cochrane Central databases until April 2022.Our search included diagnostic accuracy studies that evaluated at least one of the index tests(^(13)C-UBT or ^(14)C-UBT)against a reference standard.We used the QUADAS-2 tool to assess the methodo-logical quality of the studies.We utilized the bivariate random-effects model to calculate sensitivity,specificity,positive and negative test likelihood ratios(LR+and LR-),as well as the diagnostic odds ratio(DOR),and their 95%confidence intervals.We conducted subgroup analyses based on urea dosing,time after urea administration,and assessment technique.To investigate a possible threshold effect,we conducted Spearman correlation analysis,and we generated summary receiver operating characteristic(SROC)curves to assess heterogeneity.Finally,we visually inspected a funnel plot and used Egger’s test to evaluate publication bias.endorsing both as reliable diagnostic tools in clinical practice.CONCLUSION In summary,our study has demonstrated that ^(13)C-UBT has been found to outperform the ^(14)C-UBT,making it the preferred diagnostic approach.Additionally,our results emphasize the significance of carefully considering urea dosage,assessment timing,and measurement techniques for both tests to enhance diagnostic precision.Nevertheless,it is crucial for researchers and clinicians to evaluate the strengths and limitations of our findings before implementing them in practice.展开更多
BACKGROUND A reliable test is essential for diagnosing Helicobacter pylori(H.pylori)infection,and crucial for managing H.pylori-related diseases.Serving as an excellent method for detecting H.pylori infection,histolog...BACKGROUND A reliable test is essential for diagnosing Helicobacter pylori(H.pylori)infection,and crucial for managing H.pylori-related diseases.Serving as an excellent method for detecting H.pylori infection,histologic examination is a test that clinicians heavily rely on,especially when complemented with immunohistochemistry(IHC).Additionally,other diagnostic tests for H.pylori,such as the rapid urease test(CLO test)and stool antigen test(SA),are also highly sensitive and specific.Typically,the results of histology and other tests align with each other.However,on rare occasions,discrepancy between histopathology and other H.pylori diagnostic tests occurs.AIM To investigate the discordance between histology and other H.pylori tests,the underlying causes,and the impact on clinical management.METHODS Pathology reports of gastric biopsies were retrieved spanning August 2013 and July 2018.Reports were included in the study only if there were other H.pylori tests within seven days of the biopsy.These additional tests include CLO test,SA,and H.pylori culture.Concordance between histopathology and other tests was determined based on the consistency of results.In instances where histology results were negative while other tests were positive,the slides were retrieved for re-assessment,and the clinical chart was reviewed.RESULTS Of 1396 pathology reports were identified,each accompanied by one additional H.pylori test.The concordance rates in detecting H.pylori infection between biopsy and other tests did not exhibit significant differences based on the number of biopsy fragments.117 discrepant cases were identified.Only 20 cases(9 with CLO test and 11 with SA)had negative biopsy but positive results in other tests.Four cases initially stained with Warthin-Starry turned out to be positive for H.pylori with subsequent IHC staining.Among the remaining 16 true discrepant cases,10 patients were on proton pump inhibitors before the biopsy and/or other tests.Most patients underwent treatment,except for two who were untreated,and two patients who were lost to follow-up.CONCLUSION There are rare discrepant cases with negative biopsy but positive in SA or CLO test.Various factors may contribute to this inconsistency.Most patients in such cases had undergone treatment.展开更多
Background: The persistence of the rapid spread of the COVID-19 pandemic is linked to the appearance of several variants of SARS-CoV2 with an impact on biological diagnosis, treatment and vaccination. The United State...Background: The persistence of the rapid spread of the COVID-19 pandemic is linked to the appearance of several variants of SARS-CoV2 with an impact on biological diagnosis, treatment and vaccination. The United States Food and Drug Administration (FDA) has granted several SARS-CoV-2 detection tests Emergency Use Authorization (EUA) for diagnosis and better epidemiological surveillance. Thus, multiple RT-PCR tests have been developed and brought to market in order to meet the urgent need for the diagnosis of COVID-19. However, comparative data between these tests in clinical laboratories are scarcely available to assess their performance. Objective: To compare two molecular methods for detecting SARS-CoV-2: the RT-PCR, Allplex™2019-nCoV tests on CFX96 Bio-Rad and the Abbott m2000sp/rt RealTime SARS-CoV-2. Materials and Methods: Nasopharyngeal and oropharyngeal swabs were taken from patients to diagnose SARS-CoV-2 infection. For each sample, we searched for the virus with two different RT-PCR tests: 1) first on Abbott m2000 SARS-CoV-2 targeting the N and RdRp genes, 2) then on Allplex™2019-nCoV Assay looking for the E, N and RdRp genes. Results: Percentages of the agreement were calculated. A total of 100 samples that tested negative and 90 positives on Abbott m2000 SARS-CoV-2 were retested on Allplex™2019-nCoV. Overall agreement was 74.74% on all samples. The specific agreement was 84% and 64.4% respectively for negative and positive samples with the RealTime SARS-CoV-2 test. A positive correlation (r<sup>2</sup> = 0.63;p Conclusion: Our results showed good overall agreement between RT-PCR, Allplex™2019-nCoV and Abbott RealTime SARS-CoV-2 tests in the diagnosis of COVID-19. As the concordance is low for small viremias, the RT-PCR Allplex™2019-nCoV Assay would be better indicated during the acute and symptomatic phase of the disease.展开更多
Hepatitis C is a liver disease that is transmitted through contact with the blood of an infected person. An estimated 150 million individuals worldwide have been chronically infected with the hepatitis C virus(HCV). H...Hepatitis C is a liver disease that is transmitted through contact with the blood of an infected person. An estimated 150 million individuals worldwide have been chronically infected with the hepatitis C virus(HCV). Hepatitis C shows significant genetic variation in the global population, due to the high rate of viral RNA mutation. There are six variants of the virus(HCV genotypes 1, 2, 3, 4, 5, and 6), with 15 recorded subtypes that vary in prevalence across different regions of the world. A variety of devices are used to diagnose hepatitis C, including HCV antibody test, HCV viral load test, HCV genotype test and liver biopsy. Rapid, inexpensive, sensitive, and robust analytical devices are therefore essential for effective diagnosis and monitoring of disease treatment. This review provides an overview of current electrochemical immunosensor and genosensortechnologies employed in HCV detection.There are a limited number of publications showing electrochemical biosensors being used for the detection of HCV.Due to their simplicity,specificity,and reliability,electrochemical biosensor devices have potential clinical applications in several viral infections.展开更多
Despite the widespread use of malaria rapid diagnostic test(RDT)in clinical practice,there are a lot of challenges.We conducted a secondary analysis of 129 malaria RDT data from rounds 5–8 of the World Health Organiz...Despite the widespread use of malaria rapid diagnostic test(RDT)in clinical practice,there are a lot of challenges.We conducted a secondary analysis of 129 malaria RDT data from rounds 5–8 of the World Health Organization(WHO)product testing summary and discuss the causes of false-negative(FN)results with a focus on low parasite density,improper RDT storage,operation and interpretation,and Plasmodium falciparum with a pfhrp2/3 gene deletion.The results demonstrated that the malaria RDTs currently commercially available might cause FN results in practice.展开更多
The discovery of <em>Plasmodium</em> parasites and its incrimination as the principal cause of malaria in humans has continued to excite researchers towards inventing possible easier methods of diagnosing ...The discovery of <em>Plasmodium</em> parasites and its incrimination as the principal cause of malaria in humans has continued to excite researchers towards inventing possible easier methods of diagnosing and identifying these pathological agents in order to mitigate, control and eliminate its continuous scourge to humanity. Currently, three diagnostic methods have been proposed, but agreements as to whether the level of parasitaemia in an individual could connote likely confirmations in the three methods <em>i.e.</em> gold standard, RDTs’ and PCR/NESTED PCR, have continued to be a subject of debate. To lay to rest the debate as reported in many studies, we collected blood samples from 100 symptomatic patients who reported to the Jos-Nigeria hospital and using the gold standard methods, we were able to confirm that 30 (30%) samples out of the 100 blood samples collected were positive to P.<em> falciparum</em>, chiefly recorded among duffy-negative Africans. Excited with our findings, we prepared the thick blood films for each sample and used it to estimate the levels of parasitaemia (parasites density) per μl of blood (<em>i.e.</em> 1+;2+;3+ and 4+) per 100 high power fields (|HPF). We then subjected the individually confirmed parasite density samples to the other two methods <em>i.e.</em> Rapid Diagnostic Test (one-step RTD and optimal-IT<span style="white-space:nowrap;">®</span> RDT) and to molecular assay (PCR and the nested PCR). Interestingly, of the 30 positive samples, 18 (60%) were confirmed positive to the one-step and optimal-IT<span style="white-space:nowrap;">®</span> RDTS, while 3 (30%) out of the 10 (100%) samples of various parasite density subjected to molecular assay (PCR and the nested PCR) were positive to only P. <em>falciparum</em>. Statistical analysis of variance based on single factor computed using SPSS indicates a no significant difference (P > 0.05) in the parasitaemia levels of the four groups/categories of patients;<em>i.e.</em> variance ratio of 0.011976 calculated was less than F-critical (2.816466) at 5% (0.05). Whereas gold standard could be considered as the optimal method, for the PCR/NESTED PCR, the sensitivity is dependent on high level of parasitaemia.展开更多
<span style="font-family:Verdana;"><strong>Background:</strong></span><span><span><span style="font-family:""><span style="font-family:Verdana...<span style="font-family:Verdana;"><strong>Background:</strong></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> The rapid diagnostic tests play a pivotal role in the screening of viral markers in blood qualification for transfusion in limited resource setting. Therefore, it is important to assess their analytical performances to ensure their proper functioning. </span><b><span style="font-family:Verdana;">Material</span></b> <b><span style="font-family:Verdana;">and</span></b> <b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> We performed a cross-</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">sectional study by successive recruitment to assess the diagnostic value of rapid diagnostic tests algorithms using ELISA as a reference test. A total of 661 blood from donors were enrolled for this study. Rapid Diagnostic Tests (RDTs) and ELISA tests were performed for each sample by a couple of double-blinded biotechnologists. Data were collected on case report form and captured in Microsoft Excel then the file was imported and analyzed using R software version 4.0.3. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> The diagnostic accuracy for the algorithms are summarized in </span><b><span style="font-family:Verdana;">Table 1</span></b><span style="font-family:Verdana;">. For HIV-algorithm</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> the internal validity parameters were as follow: sensitivity (sens) 99.0% (95% CI = 97.8, 99.5);specificity (spec) 98.3% (95% CI = 90.9, 99.7);positive likelihood ratio (PLR) 57.4 (95% CI = 8.2, 401.0);negative likelihood ratio (NLR) 0.01 (95% CI = 0.0005, 0.02);diagnostic odd ratio (DOR) 4710. HBV-Ag/Ab RDTs achieve the following diagnostic accuracy: sens 99.7% (95% CI = 98.3, 99.9);spec 98.8% (95% CI = 96.9, 95.5);PLR 81.8 (95% CI = 30.9, 217.0);NLR 0.003 (95% CI = 0.0004, 0.02);DOR</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">14</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">110. The analytical performances of HCV-Ab RDTs were as follow: sens 98.7% (95% CI = 97.5, 99.4);spec 93.1% (95% CI = 78.0, 98.1);PLR 14.3 (95% CI = 3.8, 54.5);NLR 1.5 (95% CI = 0.8, 2.8);DOR 962.6. The parameters evaluating the external validity of RDTs screening for the three viral markers when the theorical prevalence was <</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">5% are summarized in </span><b><span style="font-family:Verdana;">Figure </span></b></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><b><span style="font-family:Verdana;">3</span></b></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">. At the prevalence < 5%, the NPV of the three RDTs were 99.96%</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> 99.99% and 99.94%. At the same prevalence</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> we found the following Positive Predictive Values (PPV) 70.82%, 77.59% and 37.35% for HIV-Ag/Ab RDTs, HBV-Ag RDTs and HCV-Ab RDTs algorithms, respectively. The overall areas under the received operating characteristic (ROC) curves were 98.6%</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> 99.2% and 99.2%;95.9% for HIV-Ag/Ab RDTs, HBV-Ag RDTs and HCV-Ab RDTs algorithms, respectively. </span><b><span style="font-family:Verdana;">Conclusion:</span></b><span style="font-family:Verdana;"> RDTs algorithms can play a pivotal role in the screening of HIV-Ab/Ag, HBs-Ag in the setting of resources limited-countries where financial and technical expertise shortages are a standard fare. However, their use for diagnostic purposes must be done with great caution and the result must necessarily be confirmed with an ELISA or molecular technique particularly for HCV-RDTs algorithm which achieved a</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">n</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> NLR value > 0.1.</span></span></span>展开更多
Hypertrophic cardiomyopathy(HCM) is the most common cause of sudden cardiac death(SCD) in the young, particularly among athletes. Identifying high risk individuals is very important for SCD prevention. The purpose of ...Hypertrophic cardiomyopathy(HCM) is the most common cause of sudden cardiac death(SCD) in the young, particularly among athletes. Identifying high risk individuals is very important for SCD prevention. The purpose of this review is to stress that noninvasive diagnostic testing is important for risk assessment. Extreme left ventricular hypertrophy and documented ventricular tachycardia and fibrillation increase the risk of SCD. Fragmented QRS and T wave inversion in multiple leads are more common in high risk patients. Cardiac magnetic resonance imaging provides complete visualization of the left ventricular chamber, allowing precise localization of the distribution of hypertrophy and measurement of wall thickness and cardiac mass. Moreover, with late gadolinium enhancement, patchy myocardial fibrosis within the area of hypertrophy can be detected, which is also helpful in risk stratification. Genetic testing is encouraged in all cases, especially in those with a family history of HCM and SCD.展开更多
Objective:To evaluate the detection of IgM and IgG antibodies to Orientia tsutsugamushi(O. tsutsugamushi) by rapid diagnostic test(RDT) and microimmunofluorescence assay(ml FA). Methods:RDT using a mixture of recombin...Objective:To evaluate the detection of IgM and IgG antibodies to Orientia tsutsugamushi(O. tsutsugamushi) by rapid diagnostic test(RDT) and microimmunofluorescence assay(ml FA). Methods:RDT using a mixture of recombinant 56-kDa proteins of O.tsutsugamushi and mIFA assay were performed on 20 patients from Fujian and 13 patients from Yunnan Province,and 82 sera samples from healthy farmers in Anhui Province and Beijing City in 2009.Comparison of the RDT and mIFA assay was performed by using X test and the P level of 【0.05 was considered to be significance.Results:Among these 82 normal sera samples,the specificity of RDT was 100%for both IgM and IgG tests.In 33 samples from patients with scrub typhus,5 cases were positively detected earlier by RDT than by mIFA in IgM test,and 2 cases were positive in IgG test.Sensitivities of RDT were 93.9%and 90.9%for IgM and IgG,respectively.The sensitivity of combination lest of IgM and IgG was 100%.Geometric mean titer diluted sera from confirmed cases by IFA and RDT assay were 1:37 vs.1:113(P【0.001) in IgM test and 1:99 vs.1:279 (P【0.05) in IgG test.Conclusions:RDT is more sensitivite than mIFA in the early diagnosis of scrub typhus and it is particularly applicable in rural areas.展开更多
Objective:To compare the two methods of rapid diagnostic tests(RDTs)and microscopy in the diagnosis of malaria.Methods:RDTs and microscopy were carried out to diagnose malaria. Percentage malaria parasitaemia was calc...Objective:To compare the two methods of rapid diagnostic tests(RDTs)and microscopy in the diagnosis of malaria.Methods:RDTs and microscopy were carried out to diagnose malaria. Percentage malaria parasitaemia was calculated on thin films and all non-acute cases of plasmodiasis with less than 0.001%malaria parasitaemia were regarded as negative.Results were simply presented as percentage positive of the total number of patients under study.The results of RDTs were compared to those of microscopy while those of RDTs based on antigen were compared to those of RDTs based on antibody.Patients' follow-up was made for all cases.Results: All the 200 patients under present study tested positive to RDTs based on malaria antibodies(serum)method(100%).128 out of 200 tested positive to RDTs based on malaria antigen(whole blood)method(64%),while 118 out of 200 patients under present study tested positive to visual microscopy of Lieshman and diluted Giemsa(59%).All patients that tested positive to microscopy also tested positive to RDTs based on antigen.All patients on the second day of follow-up were non-febrile and had antimalaria drugs.Conclusions;We conclude based on the present study that the RDTs based on malaria antigen(whole blood)method is as specific as the traditional microscopy and even appears more sensitive than microscopy.The RDTs based on antibody(serum)method is unspecific thus it should not be encouraged.It is most likely that Africa being an endemic region,formation of certain levels of malaria antibody may not be uncommon.The present study also supports the opinion that a good number of febrile cases is not due to malaria. We support WHO's report on cost effectiveness of RDTs but,recommend that only the antigen based method should possibly,be adopted in Africa and other malaria endemic regions of the world.展开更多
Logit regression analysis is widely applied in scientific studies and laboratory experiments, where skewed observations on a data set are often encountered. A number of problems with this method, for example, outliers...Logit regression analysis is widely applied in scientific studies and laboratory experiments, where skewed observations on a data set are often encountered. A number of problems with this method, for example, outliers and influential observations, can cause overdispersion when a model is fitted. In this study a systematic statistical approach, including the plotting of several indices is used to diagnose the lack-of-fit of a logistic regression model. The outliers and influential observations on data from laboratory experiments are then detected. Specifically we take account of the interaction of an internal solitary wave (ISW) with an obstacle, i.e., an underwater ridge, and also analyze the effects of the ridge height, the lower layer water depth, and the potential energy on the amplitude-based transmission rate of the ISW. As concluded, the goodness-of-fit of the revised logit regression model is better than that of the model without this approach.展开更多
This paper discusses how the positive and negative predictive values vary withcontrary variations of sensitivity and specificity at a certain disease prevalence.Let thesensitiviy be Se and the specificity be Sp at the...This paper discusses how the positive and negative predictive values vary withcontrary variations of sensitivity and specificity at a certain disease prevalence.Let thesensitiviy be Se and the specificity be Sp at the initial cutoff point,correspondingly Se’and Sp’ at a new cutoff point:A=Se’/Se:B-(1-Sp’)/(1-Sp):C=Sp’/Sp;D=(I-Se’)/(I-Se).Moving the cutoff point from the initial point to the new point,if the contrary variationsof the sensitivity and specificity satisfy the inequality A】B,then the positive predictivevalue increases,otherwise it decreases or remains unchanged.If the variations satisfy theinequality C】D,then the negative prcdictive value increases,otherwise it decreasses or re-mains unchanged.展开更多
Background: Due to the difficulty in implementing microscopy-based definitive diagnosis of malaria especially in resource-poor areas, rapid diagnostic test (RDT) kits as alternatives have been developed by different c...Background: Due to the difficulty in implementing microscopy-based definitive diagnosis of malaria especially in resource-poor areas, rapid diagnostic test (RDT) kits as alternatives have been developed by different companies. Kits from different companies may differ in sensitivity and specificity. It is therefore imperative to conduct field evaluation of kits from different manufacturers before they are recommended for widespread use in diagnosis of malaria. The present study sought to evaluate the performance of malaria RDT kits from two manufacturers against microscopy in detection of Plasmodium spp. infections among primary school children in Baringo County, Kenya. Methods: Two cross-sectional comparative surveys to assess three RDT kits (CareStart HRP-2, SD Bioline Ag-Pf and SD Bioline Ag-Pf/Pan) were conducted on 561 pupils from three primary schools within the Kerio Valley of Baringo County, Kenya. Results: A total of 561 blood samples were tested for Plasmodium spp. within a period of four months. SD Bioline Ag-Pf/ Pan RDT kit had a higher sensitivity (90%) compared to that of CareStart HRP-2 (70%) but this was not statistically significant (McNemar’s χ2 = 0.5, df = 1, p = 0.4795). The sensitivity of SD Bioline Ag-Pf was the same as that of Care Start HRP-2 (82.4%). The number of positive samples by microscopy was relatively lower than those detected by RDT kits. Two cases of non-P. falciparum infections were detected by RDT kits during the second survey. Conclusion: The results of the present study suggest that the performance of the three kits in the diagnosis of P. falciparum infections was better than microscopy. The sensitivity of SD Bioline Ag-Pf/Pan was slightly greater than that of Care Start HRP-2, although not statistically different.展开更多
Background: Failure to demonstrate the presence of malaria parasites prior to treatment with anti-malarial drugs remains a challenge in Uganda, often resulting into over-prescription of anti-malarial drugs to febrile ...Background: Failure to demonstrate the presence of malaria parasites prior to treatment with anti-malarial drugs remains a challenge in Uganda, often resulting into over-prescription of anti-malarial drugs to febrile patients suspected of malaria. The aim of this study was to describe the role of utilization of malaria diagnostic tests and associated factors in the receipt of anti-malarial drugs among febrile patients suspected of malaria. Methods: In a cross-sectional study design, client-exit interviews with febrile patients and key-informant interviews with purposively selected health workers were conducted at outpatient clinics of health centre IV facilities in Mukono district. Data entry and analysis were done using EpiData 3.2 and STATA 10 respectively. Data were described using frequency distributions and proportions. Chi square was used in two by two tables, odds ratios as the measure of association and an alpha level of 0.05 was used in all significance tests. Results: Out of 408 respondents, the majority were female (252, 61.8%) and a third of the samples were aged five years and below. The mean age in years was 3.3 with a standard deviation of 2.1. More than half of the respondents (359, 88%) utilized malaria diagnostic tests and about half (241, 59%) received anti-malarial drugs. There were no statistically significant differences between utilizers and non-utilizers in most characteristics except age, history of indoor residual spraying and perceived satisfaction with services at outpatient clinics. Utilizers were 75% less likely to receive anti-malarial drugs than non-utilizers after controlling for age, sex and residence (OR: 0.25, 95%CI: 0.09, 0.66). Frequent power cut-offs as well as limited knowledge on malaria treatment guidelines amongst laboratory personnel were some of the major limitations to microscopic diagnosis of malaria. Conclusion: Utilizers were 75% less likely to receive anti-malarial drugs as opposed to non-utilizers. This implies that increasing utilization of malaria diagnostic tests can reduce the problem of over-prescription of anti-malarial drugs by 75% among those tested for malaria, since anti-malarial drugs would be received by only those with a parasi- tologically-confirmed diagnosis of malaria. Policy implications: To overcome the problem of over-prescription of anti-malarial drugs, there must be a policy that ensures a consistent power supply in all public health laboratories. Training of health workers should encompass all cadres and work-shifts for laboratory personnel should be established to enhance utilization of malaria diagnostic tests especially at night.展开更多
According to the guidelines by the Japanese government, optical colonoscopy is the most strongly recommended diagnostic test after screening with the immunochemical fecal occult blood test (iFOBT), followed by double-...According to the guidelines by the Japanese government, optical colonoscopy is the most strongly recommended diagnostic test after screening with the immunochemical fecal occult blood test (iFOBT), followed by double-contrast barium enema (BE) or sigmoidoscopy. Our study was to assess patterns and trends of colorectal cancer (CRC) diagnostic testing within 2 years after iFOBT. We analyzed both iFOBT results and claims data provided by employee health insurance societies in Japan from 2005 to 2010. 25,596 enrollees underwent iFOBT screening. The positive rate was 5.1%. 32.3% of those positive underwent diagnostic tests and 1.0% (12 patients) were confirmed as having cancer. The most common test was optical colonoscopy (77.2% of total tests), followed by BE (16.2%). From 2006 to 2009, the rate of optical colonoscopy for females increased from 55% to 82% and that of BE declined from 36% to 12%, while no significant changes were seen for males. Only one-third of those who tested positive underwent diagnostic test in the 2 years following screening iFOBT. As official guidelines for diagnostic testing of CRC recommend, optical colonoscopy is now the most commonly used diagnostic test after positive iFOBT result for enrollees in employee health insurance societies in Japan.展开更多
Purpose: This article reports the results of a blinded fibre diffraction study of skin samples taken from TRAMP mice and age-matched controls to determine whether changes noted in fibre diffraction studies of human sk...Purpose: This article reports the results of a blinded fibre diffraction study of skin samples taken from TRAMP mice and age-matched controls to determine whether changes noted in fibre diffraction studies of human skin were present in these TRAMP mice studies. These mice are bred to progress to Gleeson Type 3 to Type 5 prostate cancer. Methods: Small strips, 1 mm × 5 mm, cut from the mouse skin samples were loaded into cells in the same way as human samples and slightly stretched to remove the crimp. They remained fully hydrated throughout exposure to the synchrotron beam. Results: The added change that was reported for prostate cancer in 2009 was obtained for all TRAMP mice samples, indicating that this change can be read as High Grade Cancer in human diagnostic tests. Discussion: These changes were evident for all 3 and 7 week old TRAMP mice samples but not for any of the control samples. This indicates that the changes in the fibre diffraction patterns appear much earlier than in any other available prostate cancer diagnostic test, as none of these can verify the presence of prostate cancer in the TRAMP mice before 10 weeks of age. The fibre diffraction test is therefore the most accurate and earliest test for high grade prostate cancer.展开更多
Malaria infection is the most common diagnosis made in Africa. Efficient diagnosis of malaria parasite is very vital for treatment of malaria infection. The efficacy of rapid diagnostic tests (RDTs) in comparison to m...Malaria infection is the most common diagnosis made in Africa. Efficient diagnosis of malaria parasite is very vital for treatment of malaria infection. The efficacy of rapid diagnostic tests (RDTs) in comparison to microscopy, the gold standard, in the diagnosis of malaria in Nigeria has not been fully ascertained. This study compared the sensitivity, specificity and predictive values of RDTs available in Nigeria market with microscopy. Two RDT kits were used and their results were compared with the gold standard, microscopy using thick and thin blood films (TBF and tBF). TBF had sensitivity of 85%, specificity of 30%, positive predictive value (PPV) of 55.2%, and negative predictive value (NPV) of 66.6%;tBF had sensitivity of 80%, specificity of 35%, positive predictive value (PPV) of 55.2%, and negative predictive value (NPV) of 63.6%. Among the RDTs, Care Start HRP2 kit had sensitivity of 65%, specificity of 50%, positive predictive value (PPV) of 56.5%, and negative predictive value (NPV) of 59% while SD Bioline kit had sensitivity of 55%, specificity of 65%, PPV of 61%, and NPV of 59%. It can thus be inferred that rapid diagnostic test kits are not as sensitive as microscopy in diagnosis of malaria parasite, but they are more accurate and are thus suitable alternatives to microscopy.展开更多
The two most common techniques available for diagnosis of malaria in Nigeria are microscopy and rapid diagnostic tests (RDTs). However, in diagnosing asymptomatic Plasmodium parasitaemia among donors, the preferred te...The two most common techniques available for diagnosis of malaria in Nigeria are microscopy and rapid diagnostic tests (RDTs). However, in diagnosing asymptomatic Plasmodium parasitaemia among donors, the preferred technique should not only be timely but must not compromise diagnosis. It should be more sensitive with minimal chances of false negative results. This study was carried out to compare microscopy and RDTs as effective tools for diagnosis of Plasmodium parasitaemia among blood donors in Port Harcourt. There were 200 donors involved in the study among which 135 (67.5%) tested positive and 65 (32.5%) tested negative on microscopy whereas 30 (15.0%) tested positive and 170 (85.0%) tested negative to RDT with a statistically significant difference between both techniques. Data were analysed using the statistical package epi-info version 7.02. We therefore recommend that microscopy using giemsa-stained blood films remain the method of choice for diagnosis of Plasmodium parasitaemia among blood donors to prevent the spread of transfusion malaria.展开更多
Malaria is the most common single diagnosis made in many countries in Africa. Microscopy is the gold standard for laboratory diagnosis of malaria parasite, but it requires adequate training and the time to get results...Malaria is the most common single diagnosis made in many countries in Africa. Microscopy is the gold standard for laboratory diagnosis of malaria parasite, but it requires adequate training and the time to get results is longer than that for Rapid Diagnostic Tests (RDTs). Use of RDTs is an alternative diagnostic method. This method is quick and easy to carry out. This study examined 412 blood samples of patients who met the study inclusion criteria from the health centres. All of the samples obtained were tested by SD Bioline malaria Ag P.f test commonly available in Nigeria and parasite count was done from thick film prepared. The results obtained were presented as a proportion positive in comparison to the total number of participants enrolled. Of the 412 enrollees, 284 were tested positive with malaria using the RDT, 400 were tested positive with microscopy and 12 were negative using microscopy and RDT. This study confirms the superior sensitivity of microscopy to RDTs in diagnosis of malaria. Although RDTs are very useful for quick diagnosis of malaria, particularly in areas where access to the use of microscopy is not available, the possibility of a low performance by RDTs in malaria diagnosis should be emphasized on health practitioners and microcopy should be encouraged as much as possible.展开更多
COVID 19 has caused capitulation from healthcare entities all over the world. First described in Hubei, China, the virus has spread to 185 countries, showing little signs of eradication or eradication. There does not ...COVID 19 has caused capitulation from healthcare entities all over the world. First described in Hubei, China, the virus has spread to 185 countries, showing little signs of eradication or eradication. There does not exist a medical treatment regimen or a vaccine to address COVID 19 definitively. The best response, to date, has been early diagnosis and immediate isolation or quarantine of the patient, with supportive care. As medical institutions all around the world struggle to keep up with this pandemic, there is not a consensus amongst medical professionals in the rapid diagnosis of this disease entity. Purpose: The purpose of our study was to review the literature and establish a test, or tests, that would aid the clinician in attaining a swift, yet accurate diagnosis. Methods: We searched PubMed and Google scholar and reviewed 32 articles. Keyword searches consisted of COVID 19, pandemic, diagnoses, diagnostic testing, pandemic amongst others. We compared the data obtained from these studies in an effort to find the best diagnostic test. Results: There were a total of 12,270 patients that were in our study [1]-[32]. This is the largest study to date in the literature addressing diagnosis of COVID 19. Fever, cough and fatigue, in that respective order were the most common clinical symptoms. Laboratory findings consisted of leukopenia, elevated erythrocyte sedimentation (ESR) and elevated C-reactive protein, CRP. The gold standard test described in multiple studies was the RT-PCR. Serum assays of IgM and IgG were also drawn and found to be accurate in 93% of the time. CT Chest was both sensitive and specific, 90% and 86%. This diagnostic imaging was even more successful when coupled with clinical symptoms and approaching days 7 - 12 since the onset of clinical symptoms. Discussion: This is the largest study compiled to address diagnostic testing in COVID 19 patients. The patient population is spread vastly around the world, with access to many reported tests limited in certain countries. Given the significant sensitivity and specificity of diagnostic imaging, in the setting of clinical symptoms, we recommend patient undergo CT Chest in the face of COVID 19 exposure and clinical symptoms. While RT-PCR, IgM-IgG assays are beneficial, isolation, treatment, and possible quarantine of presumptive positive COVID 19 patients (based upon clinical symptoms and imaging) should not be delayed, for fear of increased infectivity and further risk to society at large.展开更多
基金Supported by Scientific Initiation Scholarship Programme(PIBIC)of the Bahia State Research Support Foundationthe Doctorate Scholarship Program of the Coordination of Improvement of Higher Education Personnel+1 种基金the Scientific Initiation Scholarship Programme(PIBIC)of the National Council for Scientific and Technological Developmentand the CNPq Research Productivity Fellowship.
文摘BACKGROUND Helicobacter pylori(H.pylori)infection has been well-established as a significant risk factor for several gastrointestinal disorders.The urea breath test(UBT)has emerged as a leading non-invasive method for detecting H.pylori.Despite numerous studies confirming its substantial accuracy,the reliability of UBT results is often compromised by inherent limitations.These findings underscore the need for a rigorous statistical synthesis to clarify and reconcile the diagnostic accuracy of the UBT for the diagnosis of H.pylori infection.AIM To determine and compare the diagnostic accuracy of 13C-UBT and 14C-UBT for H.pylori infection in adult patients with dyspepsia.METHODS We conducted an independent search of the PubMed/MEDLINE,EMBASE,and Cochrane Central databases until April 2022.Our search included diagnostic accuracy studies that evaluated at least one of the index tests(^(13)C-UBT or ^(14)C-UBT)against a reference standard.We used the QUADAS-2 tool to assess the methodo-logical quality of the studies.We utilized the bivariate random-effects model to calculate sensitivity,specificity,positive and negative test likelihood ratios(LR+and LR-),as well as the diagnostic odds ratio(DOR),and their 95%confidence intervals.We conducted subgroup analyses based on urea dosing,time after urea administration,and assessment technique.To investigate a possible threshold effect,we conducted Spearman correlation analysis,and we generated summary receiver operating characteristic(SROC)curves to assess heterogeneity.Finally,we visually inspected a funnel plot and used Egger’s test to evaluate publication bias.endorsing both as reliable diagnostic tools in clinical practice.CONCLUSION In summary,our study has demonstrated that ^(13)C-UBT has been found to outperform the ^(14)C-UBT,making it the preferred diagnostic approach.Additionally,our results emphasize the significance of carefully considering urea dosage,assessment timing,and measurement techniques for both tests to enhance diagnostic precision.Nevertheless,it is crucial for researchers and clinicians to evaluate the strengths and limitations of our findings before implementing them in practice.
文摘BACKGROUND A reliable test is essential for diagnosing Helicobacter pylori(H.pylori)infection,and crucial for managing H.pylori-related diseases.Serving as an excellent method for detecting H.pylori infection,histologic examination is a test that clinicians heavily rely on,especially when complemented with immunohistochemistry(IHC).Additionally,other diagnostic tests for H.pylori,such as the rapid urease test(CLO test)and stool antigen test(SA),are also highly sensitive and specific.Typically,the results of histology and other tests align with each other.However,on rare occasions,discrepancy between histopathology and other H.pylori diagnostic tests occurs.AIM To investigate the discordance between histology and other H.pylori tests,the underlying causes,and the impact on clinical management.METHODS Pathology reports of gastric biopsies were retrieved spanning August 2013 and July 2018.Reports were included in the study only if there were other H.pylori tests within seven days of the biopsy.These additional tests include CLO test,SA,and H.pylori culture.Concordance between histopathology and other tests was determined based on the consistency of results.In instances where histology results were negative while other tests were positive,the slides were retrieved for re-assessment,and the clinical chart was reviewed.RESULTS Of 1396 pathology reports were identified,each accompanied by one additional H.pylori test.The concordance rates in detecting H.pylori infection between biopsy and other tests did not exhibit significant differences based on the number of biopsy fragments.117 discrepant cases were identified.Only 20 cases(9 with CLO test and 11 with SA)had negative biopsy but positive results in other tests.Four cases initially stained with Warthin-Starry turned out to be positive for H.pylori with subsequent IHC staining.Among the remaining 16 true discrepant cases,10 patients were on proton pump inhibitors before the biopsy and/or other tests.Most patients underwent treatment,except for two who were untreated,and two patients who were lost to follow-up.CONCLUSION There are rare discrepant cases with negative biopsy but positive in SA or CLO test.Various factors may contribute to this inconsistency.Most patients in such cases had undergone treatment.
文摘Background: The persistence of the rapid spread of the COVID-19 pandemic is linked to the appearance of several variants of SARS-CoV2 with an impact on biological diagnosis, treatment and vaccination. The United States Food and Drug Administration (FDA) has granted several SARS-CoV-2 detection tests Emergency Use Authorization (EUA) for diagnosis and better epidemiological surveillance. Thus, multiple RT-PCR tests have been developed and brought to market in order to meet the urgent need for the diagnosis of COVID-19. However, comparative data between these tests in clinical laboratories are scarcely available to assess their performance. Objective: To compare two molecular methods for detecting SARS-CoV-2: the RT-PCR, Allplex™2019-nCoV tests on CFX96 Bio-Rad and the Abbott m2000sp/rt RealTime SARS-CoV-2. Materials and Methods: Nasopharyngeal and oropharyngeal swabs were taken from patients to diagnose SARS-CoV-2 infection. For each sample, we searched for the virus with two different RT-PCR tests: 1) first on Abbott m2000 SARS-CoV-2 targeting the N and RdRp genes, 2) then on Allplex™2019-nCoV Assay looking for the E, N and RdRp genes. Results: Percentages of the agreement were calculated. A total of 100 samples that tested negative and 90 positives on Abbott m2000 SARS-CoV-2 were retested on Allplex™2019-nCoV. Overall agreement was 74.74% on all samples. The specific agreement was 84% and 64.4% respectively for negative and positive samples with the RealTime SARS-CoV-2 test. A positive correlation (r<sup>2</sup> = 0.63;p Conclusion: Our results showed good overall agreement between RT-PCR, Allplex™2019-nCoV and Abbott RealTime SARS-CoV-2 tests in the diagnosis of COVID-19. As the concordance is low for small viremias, the RT-PCR Allplex™2019-nCoV Assay would be better indicated during the acute and symptomatic phase of the disease.
基金Supported by Brazilian funding agencies(Sao Paulo Research Foundation-FAPESP and National Council for Scientific and Technological Development-CNPq)
文摘Hepatitis C is a liver disease that is transmitted through contact with the blood of an infected person. An estimated 150 million individuals worldwide have been chronically infected with the hepatitis C virus(HCV). Hepatitis C shows significant genetic variation in the global population, due to the high rate of viral RNA mutation. There are six variants of the virus(HCV genotypes 1, 2, 3, 4, 5, and 6), with 15 recorded subtypes that vary in prevalence across different regions of the world. A variety of devices are used to diagnose hepatitis C, including HCV antibody test, HCV viral load test, HCV genotype test and liver biopsy. Rapid, inexpensive, sensitive, and robust analytical devices are therefore essential for effective diagnosis and monitoring of disease treatment. This review provides an overview of current electrochemical immunosensor and genosensortechnologies employed in HCV detection.There are a limited number of publications showing electrochemical biosensors being used for the detection of HCV.Due to their simplicity,specificity,and reliability,electrochemical biosensor devices have potential clinical applications in several viral infections.
基金supported by the National Grand Program on Key Infectious Disease(2018ZX10103002-001-007)the Biosafety Special Program(19SWAQ 13)。
文摘Despite the widespread use of malaria rapid diagnostic test(RDT)in clinical practice,there are a lot of challenges.We conducted a secondary analysis of 129 malaria RDT data from rounds 5–8 of the World Health Organization(WHO)product testing summary and discuss the causes of false-negative(FN)results with a focus on low parasite density,improper RDT storage,operation and interpretation,and Plasmodium falciparum with a pfhrp2/3 gene deletion.The results demonstrated that the malaria RDTs currently commercially available might cause FN results in practice.
文摘The discovery of <em>Plasmodium</em> parasites and its incrimination as the principal cause of malaria in humans has continued to excite researchers towards inventing possible easier methods of diagnosing and identifying these pathological agents in order to mitigate, control and eliminate its continuous scourge to humanity. Currently, three diagnostic methods have been proposed, but agreements as to whether the level of parasitaemia in an individual could connote likely confirmations in the three methods <em>i.e.</em> gold standard, RDTs’ and PCR/NESTED PCR, have continued to be a subject of debate. To lay to rest the debate as reported in many studies, we collected blood samples from 100 symptomatic patients who reported to the Jos-Nigeria hospital and using the gold standard methods, we were able to confirm that 30 (30%) samples out of the 100 blood samples collected were positive to P.<em> falciparum</em>, chiefly recorded among duffy-negative Africans. Excited with our findings, we prepared the thick blood films for each sample and used it to estimate the levels of parasitaemia (parasites density) per μl of blood (<em>i.e.</em> 1+;2+;3+ and 4+) per 100 high power fields (|HPF). We then subjected the individually confirmed parasite density samples to the other two methods <em>i.e.</em> Rapid Diagnostic Test (one-step RTD and optimal-IT<span style="white-space:nowrap;">®</span> RDT) and to molecular assay (PCR and the nested PCR). Interestingly, of the 30 positive samples, 18 (60%) were confirmed positive to the one-step and optimal-IT<span style="white-space:nowrap;">®</span> RDTS, while 3 (30%) out of the 10 (100%) samples of various parasite density subjected to molecular assay (PCR and the nested PCR) were positive to only P. <em>falciparum</em>. Statistical analysis of variance based on single factor computed using SPSS indicates a no significant difference (P > 0.05) in the parasitaemia levels of the four groups/categories of patients;<em>i.e.</em> variance ratio of 0.011976 calculated was less than F-critical (2.816466) at 5% (0.05). Whereas gold standard could be considered as the optimal method, for the PCR/NESTED PCR, the sensitivity is dependent on high level of parasitaemia.
文摘<span style="font-family:Verdana;"><strong>Background:</strong></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> The rapid diagnostic tests play a pivotal role in the screening of viral markers in blood qualification for transfusion in limited resource setting. Therefore, it is important to assess their analytical performances to ensure their proper functioning. </span><b><span style="font-family:Verdana;">Material</span></b> <b><span style="font-family:Verdana;">and</span></b> <b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> We performed a cross-</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">sectional study by successive recruitment to assess the diagnostic value of rapid diagnostic tests algorithms using ELISA as a reference test. A total of 661 blood from donors were enrolled for this study. Rapid Diagnostic Tests (RDTs) and ELISA tests were performed for each sample by a couple of double-blinded biotechnologists. Data were collected on case report form and captured in Microsoft Excel then the file was imported and analyzed using R software version 4.0.3. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> The diagnostic accuracy for the algorithms are summarized in </span><b><span style="font-family:Verdana;">Table 1</span></b><span style="font-family:Verdana;">. For HIV-algorithm</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> the internal validity parameters were as follow: sensitivity (sens) 99.0% (95% CI = 97.8, 99.5);specificity (spec) 98.3% (95% CI = 90.9, 99.7);positive likelihood ratio (PLR) 57.4 (95% CI = 8.2, 401.0);negative likelihood ratio (NLR) 0.01 (95% CI = 0.0005, 0.02);diagnostic odd ratio (DOR) 4710. HBV-Ag/Ab RDTs achieve the following diagnostic accuracy: sens 99.7% (95% CI = 98.3, 99.9);spec 98.8% (95% CI = 96.9, 95.5);PLR 81.8 (95% CI = 30.9, 217.0);NLR 0.003 (95% CI = 0.0004, 0.02);DOR</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">14</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">110. The analytical performances of HCV-Ab RDTs were as follow: sens 98.7% (95% CI = 97.5, 99.4);spec 93.1% (95% CI = 78.0, 98.1);PLR 14.3 (95% CI = 3.8, 54.5);NLR 1.5 (95% CI = 0.8, 2.8);DOR 962.6. The parameters evaluating the external validity of RDTs screening for the three viral markers when the theorical prevalence was <</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">5% are summarized in </span><b><span style="font-family:Verdana;">Figure </span></b></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><b><span style="font-family:Verdana;">3</span></b></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">. At the prevalence < 5%, the NPV of the three RDTs were 99.96%</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> 99.99% and 99.94%. At the same prevalence</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> we found the following Positive Predictive Values (PPV) 70.82%, 77.59% and 37.35% for HIV-Ag/Ab RDTs, HBV-Ag RDTs and HCV-Ab RDTs algorithms, respectively. The overall areas under the received operating characteristic (ROC) curves were 98.6%</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> 99.2% and 99.2%;95.9% for HIV-Ag/Ab RDTs, HBV-Ag RDTs and HCV-Ab RDTs algorithms, respectively. </span><b><span style="font-family:Verdana;">Conclusion:</span></b><span style="font-family:Verdana;"> RDTs algorithms can play a pivotal role in the screening of HIV-Ab/Ag, HBs-Ag in the setting of resources limited-countries where financial and technical expertise shortages are a standard fare. However, their use for diagnostic purposes must be done with great caution and the result must necessarily be confirmed with an ELISA or molecular technique particularly for HCV-RDTs algorithm which achieved a</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">n</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> NLR value > 0.1.</span></span></span>
文摘Hypertrophic cardiomyopathy(HCM) is the most common cause of sudden cardiac death(SCD) in the young, particularly among athletes. Identifying high risk individuals is very important for SCD prevention. The purpose of this review is to stress that noninvasive diagnostic testing is important for risk assessment. Extreme left ventricular hypertrophy and documented ventricular tachycardia and fibrillation increase the risk of SCD. Fragmented QRS and T wave inversion in multiple leads are more common in high risk patients. Cardiac magnetic resonance imaging provides complete visualization of the left ventricular chamber, allowing precise localization of the distribution of hypertrophy and measurement of wall thickness and cardiac mass. Moreover, with late gadolinium enhancement, patchy myocardial fibrosis within the area of hypertrophy can be detected, which is also helpful in risk stratification. Genetic testing is encouraged in all cases, especially in those with a family history of HCM and SCD.
基金supported by the National Basil Research Program of China(973 Program) 2010CBS30200(2010CB530206)the grants from the National Key Science and Technolog Projects of China,No.2009ZX10004-203 and 2008ZX10004-008)
文摘Objective:To evaluate the detection of IgM and IgG antibodies to Orientia tsutsugamushi(O. tsutsugamushi) by rapid diagnostic test(RDT) and microimmunofluorescence assay(ml FA). Methods:RDT using a mixture of recombinant 56-kDa proteins of O.tsutsugamushi and mIFA assay were performed on 20 patients from Fujian and 13 patients from Yunnan Province,and 82 sera samples from healthy farmers in Anhui Province and Beijing City in 2009.Comparison of the RDT and mIFA assay was performed by using X test and the P level of 【0.05 was considered to be significance.Results:Among these 82 normal sera samples,the specificity of RDT was 100%for both IgM and IgG tests.In 33 samples from patients with scrub typhus,5 cases were positively detected earlier by RDT than by mIFA in IgM test,and 2 cases were positive in IgG test.Sensitivities of RDT were 93.9%and 90.9%for IgM and IgG,respectively.The sensitivity of combination lest of IgM and IgG was 100%.Geometric mean titer diluted sera from confirmed cases by IFA and RDT assay were 1:37 vs.1:113(P【0.001) in IgM test and 1:99 vs.1:279 (P【0.05) in IgG test.Conclusions:RDT is more sensitivite than mIFA in the early diagnosis of scrub typhus and it is particularly applicable in rural areas.
文摘Objective:To compare the two methods of rapid diagnostic tests(RDTs)and microscopy in the diagnosis of malaria.Methods:RDTs and microscopy were carried out to diagnose malaria. Percentage malaria parasitaemia was calculated on thin films and all non-acute cases of plasmodiasis with less than 0.001%malaria parasitaemia were regarded as negative.Results were simply presented as percentage positive of the total number of patients under study.The results of RDTs were compared to those of microscopy while those of RDTs based on antigen were compared to those of RDTs based on antibody.Patients' follow-up was made for all cases.Results: All the 200 patients under present study tested positive to RDTs based on malaria antibodies(serum)method(100%).128 out of 200 tested positive to RDTs based on malaria antigen(whole blood)method(64%),while 118 out of 200 patients under present study tested positive to visual microscopy of Lieshman and diluted Giemsa(59%).All patients that tested positive to microscopy also tested positive to RDTs based on antigen.All patients on the second day of follow-up were non-febrile and had antimalaria drugs.Conclusions;We conclude based on the present study that the RDTs based on malaria antigen(whole blood)method is as specific as the traditional microscopy and even appears more sensitive than microscopy.The RDTs based on antibody(serum)method is unspecific thus it should not be encouraged.It is most likely that Africa being an endemic region,formation of certain levels of malaria antibody may not be uncommon.The present study also supports the opinion that a good number of febrile cases is not due to malaria. We support WHO's report on cost effectiveness of RDTs but,recommend that only the antigen based method should possibly,be adopted in Africa and other malaria endemic regions of the world.
基金Science Council of Taiwan Province under Grant Nos.NSC 96-2628-E-366-004-MY2 and 96-2628-E-132-001-MY2
文摘Logit regression analysis is widely applied in scientific studies and laboratory experiments, where skewed observations on a data set are often encountered. A number of problems with this method, for example, outliers and influential observations, can cause overdispersion when a model is fitted. In this study a systematic statistical approach, including the plotting of several indices is used to diagnose the lack-of-fit of a logistic regression model. The outliers and influential observations on data from laboratory experiments are then detected. Specifically we take account of the interaction of an internal solitary wave (ISW) with an obstacle, i.e., an underwater ridge, and also analyze the effects of the ridge height, the lower layer water depth, and the potential energy on the amplitude-based transmission rate of the ISW. As concluded, the goodness-of-fit of the revised logit regression model is better than that of the model without this approach.
文摘This paper discusses how the positive and negative predictive values vary withcontrary variations of sensitivity and specificity at a certain disease prevalence.Let thesensitiviy be Se and the specificity be Sp at the initial cutoff point,correspondingly Se’and Sp’ at a new cutoff point:A=Se’/Se:B-(1-Sp’)/(1-Sp):C=Sp’/Sp;D=(I-Se’)/(I-Se).Moving the cutoff point from the initial point to the new point,if the contrary variationsof the sensitivity and specificity satisfy the inequality A】B,then the positive predictivevalue increases,otherwise it decreases or remains unchanged.If the variations satisfy theinequality C】D,then the negative prcdictive value increases,otherwise it decreasses or re-mains unchanged.
文摘Background: Due to the difficulty in implementing microscopy-based definitive diagnosis of malaria especially in resource-poor areas, rapid diagnostic test (RDT) kits as alternatives have been developed by different companies. Kits from different companies may differ in sensitivity and specificity. It is therefore imperative to conduct field evaluation of kits from different manufacturers before they are recommended for widespread use in diagnosis of malaria. The present study sought to evaluate the performance of malaria RDT kits from two manufacturers against microscopy in detection of Plasmodium spp. infections among primary school children in Baringo County, Kenya. Methods: Two cross-sectional comparative surveys to assess three RDT kits (CareStart HRP-2, SD Bioline Ag-Pf and SD Bioline Ag-Pf/Pan) were conducted on 561 pupils from three primary schools within the Kerio Valley of Baringo County, Kenya. Results: A total of 561 blood samples were tested for Plasmodium spp. within a period of four months. SD Bioline Ag-Pf/ Pan RDT kit had a higher sensitivity (90%) compared to that of CareStart HRP-2 (70%) but this was not statistically significant (McNemar’s χ2 = 0.5, df = 1, p = 0.4795). The sensitivity of SD Bioline Ag-Pf was the same as that of Care Start HRP-2 (82.4%). The number of positive samples by microscopy was relatively lower than those detected by RDT kits. Two cases of non-P. falciparum infections were detected by RDT kits during the second survey. Conclusion: The results of the present study suggest that the performance of the three kits in the diagnosis of P. falciparum infections was better than microscopy. The sensitivity of SD Bioline Ag-Pf/Pan was slightly greater than that of Care Start HRP-2, although not statistically different.
文摘Background: Failure to demonstrate the presence of malaria parasites prior to treatment with anti-malarial drugs remains a challenge in Uganda, often resulting into over-prescription of anti-malarial drugs to febrile patients suspected of malaria. The aim of this study was to describe the role of utilization of malaria diagnostic tests and associated factors in the receipt of anti-malarial drugs among febrile patients suspected of malaria. Methods: In a cross-sectional study design, client-exit interviews with febrile patients and key-informant interviews with purposively selected health workers were conducted at outpatient clinics of health centre IV facilities in Mukono district. Data entry and analysis were done using EpiData 3.2 and STATA 10 respectively. Data were described using frequency distributions and proportions. Chi square was used in two by two tables, odds ratios as the measure of association and an alpha level of 0.05 was used in all significance tests. Results: Out of 408 respondents, the majority were female (252, 61.8%) and a third of the samples were aged five years and below. The mean age in years was 3.3 with a standard deviation of 2.1. More than half of the respondents (359, 88%) utilized malaria diagnostic tests and about half (241, 59%) received anti-malarial drugs. There were no statistically significant differences between utilizers and non-utilizers in most characteristics except age, history of indoor residual spraying and perceived satisfaction with services at outpatient clinics. Utilizers were 75% less likely to receive anti-malarial drugs than non-utilizers after controlling for age, sex and residence (OR: 0.25, 95%CI: 0.09, 0.66). Frequent power cut-offs as well as limited knowledge on malaria treatment guidelines amongst laboratory personnel were some of the major limitations to microscopic diagnosis of malaria. Conclusion: Utilizers were 75% less likely to receive anti-malarial drugs as opposed to non-utilizers. This implies that increasing utilization of malaria diagnostic tests can reduce the problem of over-prescription of anti-malarial drugs by 75% among those tested for malaria, since anti-malarial drugs would be received by only those with a parasi- tologically-confirmed diagnosis of malaria. Policy implications: To overcome the problem of over-prescription of anti-malarial drugs, there must be a policy that ensures a consistent power supply in all public health laboratories. Training of health workers should encompass all cadres and work-shifts for laboratory personnel should be established to enhance utilization of malaria diagnostic tests especially at night.
文摘According to the guidelines by the Japanese government, optical colonoscopy is the most strongly recommended diagnostic test after screening with the immunochemical fecal occult blood test (iFOBT), followed by double-contrast barium enema (BE) or sigmoidoscopy. Our study was to assess patterns and trends of colorectal cancer (CRC) diagnostic testing within 2 years after iFOBT. We analyzed both iFOBT results and claims data provided by employee health insurance societies in Japan from 2005 to 2010. 25,596 enrollees underwent iFOBT screening. The positive rate was 5.1%. 32.3% of those positive underwent diagnostic tests and 1.0% (12 patients) were confirmed as having cancer. The most common test was optical colonoscopy (77.2% of total tests), followed by BE (16.2%). From 2006 to 2009, the rate of optical colonoscopy for females increased from 55% to 82% and that of BE declined from 36% to 12%, while no significant changes were seen for males. Only one-third of those who tested positive underwent diagnostic test in the 2 years following screening iFOBT. As official guidelines for diagnostic testing of CRC recommend, optical colonoscopy is now the most commonly used diagnostic test after positive iFOBT result for enrollees in employee health insurance societies in Japan.
文摘Purpose: This article reports the results of a blinded fibre diffraction study of skin samples taken from TRAMP mice and age-matched controls to determine whether changes noted in fibre diffraction studies of human skin were present in these TRAMP mice studies. These mice are bred to progress to Gleeson Type 3 to Type 5 prostate cancer. Methods: Small strips, 1 mm × 5 mm, cut from the mouse skin samples were loaded into cells in the same way as human samples and slightly stretched to remove the crimp. They remained fully hydrated throughout exposure to the synchrotron beam. Results: The added change that was reported for prostate cancer in 2009 was obtained for all TRAMP mice samples, indicating that this change can be read as High Grade Cancer in human diagnostic tests. Discussion: These changes were evident for all 3 and 7 week old TRAMP mice samples but not for any of the control samples. This indicates that the changes in the fibre diffraction patterns appear much earlier than in any other available prostate cancer diagnostic test, as none of these can verify the presence of prostate cancer in the TRAMP mice before 10 weeks of age. The fibre diffraction test is therefore the most accurate and earliest test for high grade prostate cancer.
文摘Malaria infection is the most common diagnosis made in Africa. Efficient diagnosis of malaria parasite is very vital for treatment of malaria infection. The efficacy of rapid diagnostic tests (RDTs) in comparison to microscopy, the gold standard, in the diagnosis of malaria in Nigeria has not been fully ascertained. This study compared the sensitivity, specificity and predictive values of RDTs available in Nigeria market with microscopy. Two RDT kits were used and their results were compared with the gold standard, microscopy using thick and thin blood films (TBF and tBF). TBF had sensitivity of 85%, specificity of 30%, positive predictive value (PPV) of 55.2%, and negative predictive value (NPV) of 66.6%;tBF had sensitivity of 80%, specificity of 35%, positive predictive value (PPV) of 55.2%, and negative predictive value (NPV) of 63.6%. Among the RDTs, Care Start HRP2 kit had sensitivity of 65%, specificity of 50%, positive predictive value (PPV) of 56.5%, and negative predictive value (NPV) of 59% while SD Bioline kit had sensitivity of 55%, specificity of 65%, PPV of 61%, and NPV of 59%. It can thus be inferred that rapid diagnostic test kits are not as sensitive as microscopy in diagnosis of malaria parasite, but they are more accurate and are thus suitable alternatives to microscopy.
文摘The two most common techniques available for diagnosis of malaria in Nigeria are microscopy and rapid diagnostic tests (RDTs). However, in diagnosing asymptomatic Plasmodium parasitaemia among donors, the preferred technique should not only be timely but must not compromise diagnosis. It should be more sensitive with minimal chances of false negative results. This study was carried out to compare microscopy and RDTs as effective tools for diagnosis of Plasmodium parasitaemia among blood donors in Port Harcourt. There were 200 donors involved in the study among which 135 (67.5%) tested positive and 65 (32.5%) tested negative on microscopy whereas 30 (15.0%) tested positive and 170 (85.0%) tested negative to RDT with a statistically significant difference between both techniques. Data were analysed using the statistical package epi-info version 7.02. We therefore recommend that microscopy using giemsa-stained blood films remain the method of choice for diagnosis of Plasmodium parasitaemia among blood donors to prevent the spread of transfusion malaria.
文摘Malaria is the most common single diagnosis made in many countries in Africa. Microscopy is the gold standard for laboratory diagnosis of malaria parasite, but it requires adequate training and the time to get results is longer than that for Rapid Diagnostic Tests (RDTs). Use of RDTs is an alternative diagnostic method. This method is quick and easy to carry out. This study examined 412 blood samples of patients who met the study inclusion criteria from the health centres. All of the samples obtained were tested by SD Bioline malaria Ag P.f test commonly available in Nigeria and parasite count was done from thick film prepared. The results obtained were presented as a proportion positive in comparison to the total number of participants enrolled. Of the 412 enrollees, 284 were tested positive with malaria using the RDT, 400 were tested positive with microscopy and 12 were negative using microscopy and RDT. This study confirms the superior sensitivity of microscopy to RDTs in diagnosis of malaria. Although RDTs are very useful for quick diagnosis of malaria, particularly in areas where access to the use of microscopy is not available, the possibility of a low performance by RDTs in malaria diagnosis should be emphasized on health practitioners and microcopy should be encouraged as much as possible.
文摘COVID 19 has caused capitulation from healthcare entities all over the world. First described in Hubei, China, the virus has spread to 185 countries, showing little signs of eradication or eradication. There does not exist a medical treatment regimen or a vaccine to address COVID 19 definitively. The best response, to date, has been early diagnosis and immediate isolation or quarantine of the patient, with supportive care. As medical institutions all around the world struggle to keep up with this pandemic, there is not a consensus amongst medical professionals in the rapid diagnosis of this disease entity. Purpose: The purpose of our study was to review the literature and establish a test, or tests, that would aid the clinician in attaining a swift, yet accurate diagnosis. Methods: We searched PubMed and Google scholar and reviewed 32 articles. Keyword searches consisted of COVID 19, pandemic, diagnoses, diagnostic testing, pandemic amongst others. We compared the data obtained from these studies in an effort to find the best diagnostic test. Results: There were a total of 12,270 patients that were in our study [1]-[32]. This is the largest study to date in the literature addressing diagnosis of COVID 19. Fever, cough and fatigue, in that respective order were the most common clinical symptoms. Laboratory findings consisted of leukopenia, elevated erythrocyte sedimentation (ESR) and elevated C-reactive protein, CRP. The gold standard test described in multiple studies was the RT-PCR. Serum assays of IgM and IgG were also drawn and found to be accurate in 93% of the time. CT Chest was both sensitive and specific, 90% and 86%. This diagnostic imaging was even more successful when coupled with clinical symptoms and approaching days 7 - 12 since the onset of clinical symptoms. Discussion: This is the largest study compiled to address diagnostic testing in COVID 19 patients. The patient population is spread vastly around the world, with access to many reported tests limited in certain countries. Given the significant sensitivity and specificity of diagnostic imaging, in the setting of clinical symptoms, we recommend patient undergo CT Chest in the face of COVID 19 exposure and clinical symptoms. While RT-PCR, IgM-IgG assays are beneficial, isolation, treatment, and possible quarantine of presumptive positive COVID 19 patients (based upon clinical symptoms and imaging) should not be delayed, for fear of increased infectivity and further risk to society at large.
