scholarly journals Clinical diagnostic evaluation of HRP2 and pLDH-based rapid diagnostic tests for malaria in an area receiving seasonal malaria chemoprevention in Niger

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Matthew E. Coldiron ◽  
Bachir Assao ◽  
Céline Langendorf ◽  
Nathan Sayinzoga-Makombe ◽  
Iza Ciglenecki ◽  
...  
Keyword(s):  
Positive Predictive Value ◽  
Predictive Value ◽  
Diagnostic Tests ◽  
Health Centre ◽  
Rapid Diagnostic Tests ◽  
Diagnostic Evaluation ◽  
Axillary Temperature ◽  
Transmission Season ◽  
Seasonal Malaria Chemoprevention ◽  
High Season

Abstract Background Rapid diagnostic tests (RDT) for malaria are common, but their performance varies. Tests using histidine-rich protein 2 (HRP2) antigen are most common, and many have high sensitivity. HRP2 tests can remain positive for weeks after treatment, limiting their specificity and usefulness in high-transmission settings. Tests using Plasmodium lactate dehydrogenase (pLDH) have been less widely used but have higher specificity, mostly due to a much shorter time to become negative. Methods A prospective, health centre-based, diagnostic evaluation of two malaria RDTs was performed in rural Niger during the high malaria transmission season (3–28 October, 2017) and during the low transmission season (28 January–31 March, 2018). All children under 5 years of age presenting with fever (axillary temperature > 37.5 °C) or history of fever in the previous 24 h were eligible. Capillary blood was collected by finger prick. The SD Bioline HRP2 (catalog: 05FK50) and the CareStart pLDH(pan) (catalog: RMNM-02571) were performed in parallel, and thick and thin smears were prepared. Microscopy was performed at Epicentre, Maradi, Niger, with external quality control. The target sample size was 279 children with microscopy-confirmed malaria during each transmission season. Results In the high season, the sensitivity of both tests was estimated at > 99%, but the specificity of both tests was lower: 58.0% (95% CI 52.1–63.8) for the pLDH test and 57.4% (95% CI 51.5–63.1) for the HRP2 test. The positive predictive value was 66.3% (95% CI 61.1–71.2) for both tests. In the low season, the sensitivity of both tests dropped: 91.0% (95% CI 85.3–95.0) for the pLDH test and 85.8% (95% CI 79.3–90.9) for the HRP2 test. The positive predictive value remained low for both tests in the low season: 60.5% (95% CI 53.9–66.8) for the pLDH test and 61.9% (55.0–68.4) for the HRP2 test. Performance was similar across different production lots, gender, age of the children, and, during the high season, time since the most recent distribution of seasonal malaria chemoprevention. Conclusions The low specificity of the pLDH RDT in this setting was unexpected and is not easily explained. As the pLDH test continues to be introduced into new settings, the questions raised by this study will need to be addressed.

scholarly journals The Positive Predictive Value of Diagnostic Ultrasound for Occult Herniae

2006 ◽  
Vol 88 (2) ◽  
pp. 165-167 ◽  
Author(s):  
M Bradley ◽  
J Morgan ◽  
B Pentlow ◽  
A Roe
Keyword(s):  
Positive Predictive Value ◽  
Predictive Value ◽  
Diagnostic Tests ◽  
Diagnostic Ultrasound ◽  
Pain Clinic ◽  
Diagnostic Problem ◽  
Clinical Criteria ◽  
Negative Results ◽  
Positive Results

INTRODUCTION The aim of this study is to ascertain the accuracy of diagnostic ultrasound in the assessment of the occult abdominal and groin herniae. The authors have previously demonstrated its efficacy in diagnosing the type of clinical groin herniae but occult herniae provide a further diagnostic problem. PATIENTS AND METHODS A total of 113 consecutive patients were referred prospectively for ultrasound examinations with clinically suspected occult herniae. All positive scans were offered surgery whilst the negative results were offered further imaging or other diagnostic tests depending on the clinical criteria. The end point for negative scans was based on 18-month follow-up or resolution of symptoms. RESULTS Overall, 59 scans showed positive results for herniae and 56 of these had surgery. In the other three patients, two refused an operation, and one had no hernia detected at operation. In the remaining 57 scans, ultrasound offered alternative soft tissue diagnoses in 23 patients and surgical/endoscopic diagnoses accounted for a further 8 patients. CONCLUSIONS Ultrasound offered a diagnosis for the symptomology in 82 patients (70.6%) of which 59 were herniae. The positive predictive value for hernia is 98.3%. Twenty-six patients with no diagnosis or confirmation of herniae on follow-up showed symptom resolution in 22 cases, and four patients were treated by the pain clinic.

scholarly journals Clinical overlap between malaria and pneumonia: can malaria rapid diagnostic test play a role?

2011 ◽  
Vol 5 (03) ◽  
pp. 199-203 ◽  
Author(s):  
Kingsley Nnanna Ukwaja ◽  
Olufemi B Aina ◽  
Ademola A Talabi
Keyword(s):  
Diagnostic Test ◽  
Rapid Diagnostic Test ◽  
Diagnostic Tests ◽  
Health Centre ◽  
Rapid Diagnostic Tests ◽  
Case Definition ◽  
Sub Saharan Africa ◽  
Malaria Rapid Diagnostic Test ◽  
Chi Square ◽  
Symptom Overlap

Introduction: Malaria and pneumonia account for 40% of mortality among children under five years of age in sub-Saharan Africa. Due to lack of diagnostic facilities, their management is based on the integrated management of childhood illnesses (IMCI) strategy. Symptoms of malaria and pneumonia overlap in African children, necessitating dual IMCI classifications at health centres and treatment with both antibiotics and antimalarials. This study determined the prevalence of malaria-pneumonia symptom overlap and confirmed the diagnosis of malaria in these cases using a rapid diagnostic test. Methodology: Consecutive consultations of 1,216 children (two months to five years old) were documented over a three-month period in a comprehensive health centre. Malaria rapid diagnostic tests were conducted only for children who had symptom overlap. Results: Of the 1,216 children enrolled, 1,090 (90%) reported cough or fever. Among the children fulfilling the malaria case definition, 284 (30%) also met the pneumonia case definition. Twenty-three percent (284) of all children enrolled met the criteria for both malaria and pneumonia. However, only 130 (46%) of them had a positive result for malaria using a malaria rapid diagnostic test. During a malaria-pneumonia overlap, female children (chi-square 5.9, P = 0.01) and children ≥ one year (chi-square 4.8, P = 0.003) were more likely to seek care within two days of fever. Conclusion: Dual treatment with antimalarials and antibiotics in children with malaria-pneumonia overlap may result in unnecessary over-prescription of antimalarial medications. Use of rapid diagnostic tests in their management can potentially avoid over-prescribing of malaria medications.

scholarly journals Agreement between commercially available ELISA and in-house Luminex SARS-CoV-2 antibody immunoassays

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rebeca Santano ◽  
Diana Barrios ◽  
Fàtima Crispi ◽  
Francesca Crovetto ◽  
Marta Vidal ◽  
...  
Keyword(s):  
Positive Predictive Value ◽  
Predictive Value ◽  
Diagnostic Tests ◽  
Distress Syndrome ◽  
Clinical Performance ◽  
External Validation ◽  
Severe Respiratory Distress ◽  
Technical Performance ◽  
Severe Respiratory Distress Syndrome

AbstractSerological diagnostic of the severe respiratory distress syndrome coronavirus 2 (SARS-CoV-2) is a valuable tool for the determination of immunity and surveillance of exposure to the virus. In the context of an ongoing pandemic, it is essential to externally validate widely used tests to assure correct diagnostics and epidemiological estimations. We evaluated the performance of the COVID-19 ELISA IgG and the COVID-19 ELISA IgM/A (Vircell, S.L.) against a highly specific and sensitive in-house Luminex immunoassay in a set of samples from pregnant women and cord blood. The agreement between both assays was moderate to high for IgG but low for IgM/A. Considering seropositivity by either IgG and/or IgM/A, the technical performance of the ELISA was highly imbalanced, with 96% sensitivity at the expense of 22% specificity. As for the clinical performance, the negative predictive value reached 87% while the positive predictive value was 51%. Our results stress the need for highly specific and sensitive assays and external validation of diagnostic tests with different sets of samples to avoid the clinical, epidemiological and personal disturbances derived from serological misdiagnosis.

scholarly journals Evaluation of two new rapid diagnostic tests (RDTs) for the diagnosis of malaria

2013 ◽  
Vol 5 (2) ◽  
pp. 11-15 ◽  
Author(s):  
Fahmida Jahan ◽  
Rubayet Elahi ◽  
Md. Khaja Mohiuddin ◽  
Md. Gulam Musawwir Khan ◽  
Mohammad Shafiul Alam ◽  
...  
Keyword(s):  
Predictive Value ◽  
Gold Standard ◽  
Diagnostic Tests ◽  
Rapid Diagnostic Tests ◽  
Accurate Diagnosis ◽  
The Other ◽  
Antibody Detection ◽  
Resource Limited Settings ◽  
Malaria Rdts ◽  
Resource Limited

Rapid diagnostic tests (RDTs) address the need for accurate diagnosis of malaria, particularly in resource limited settings. In this study, two malaria RDTs were compared with gold standard microscopy: On Site Pf/Pv test detecting Plasmodium falciparum-specific histidine rich protein-2 (Pf HR P2) and P. vivax-specific parasitic lactate dehydrogenase (pLDH) antigens; and SD Bioline anti-Pf/Pv test detecting anti-HR P2 and anti-pL DH antibodies for the diagnosis of P. falciparum and P. vivax infections, respectively. For OnSite test, the overall sensitivity was found 96.2% , specificity 98.2% , positive predictive value (PPV ) 98.2% , negative predictive value (NPV ) 96.4% and agreement with microscopy was found to be 0.94. On the other hand SD Bioline test, the overall sensitivity was 75.4%, specificity 83.7%, PPV 84.3% , NPV 74.5% and agreement with microscopy was 0.59. These data revealed that the R DT based on antigen detection (Onsite test) was more reliable than that based on the antibody detection (SD Bioline test).DOI: http://dx.doi.org/10.3329/bjmm.v5i2.16931 Bangladesh J Med Microbiol 2011; 05 (02): 11-15

scholarly journals Baseline Malaria Prevalence at the Targeted Pre-elimination Districts in Ethiopia

2020 ◽  
Author(s):  
Desalegn Nega ◽  
Adugna Abera ◽  
Bokretsion Gidey ◽  
Sindew Mekasha ◽  
Abnet Abebe ◽  
...  
Keyword(s):  
Malaria Elimination ◽  
Diagnostic Tests ◽  
Open Data ◽  
Malaria Prevalence ◽  
Rapid Diagnostic Tests ◽  
Cross Sectional Survey ◽  
Axillary Temperature ◽  
Cross Sectional ◽  
Low Transmission ◽  
Total Prevalence

Abstract Background: Encouraged by the success in malaria control and prevention strategies, several malaria endemic countries have adopted elimination strategies worldwide. Accordingly, Ethiopian ministry of health launched malaria elimination with a stepwise approach by primarily targeting the low-transmission districts and their adjacent areas/zones in order to shrink the country’s malaria map progressively. Hence, this community survey was conducted to establish baseline malaria information at the preliminary phase of elimination for measuring future intervention success in elimination goal. Methods: Community based cross-sectional survey was conducted at twenty malaria elimination targeted districts selected from five regional states and one city administration in Ethiopia. The GPS enabled smart phones programmed with Open Data Kit were used to enumerate 9326 study households and collect data from 29,993 residents. Care Start™ Malaria HRP-2/PLDH Rapid Diagnostic Tests (RDTs) were used for blood testing at field level. Armpit digital thermometers were used to measure axillary temperature.Result: Overall malaria prevalence by RDTs was 1.17% (339/28973). The prevalence at district levels ranged from 0.0% to 4.7%. The total prevalence of febrile cases (axillary temperature >37.5oc) in the survey was 9.2% (2760/29993). Among the 2,510 febrile individuals tested with RDTs, only 3.35% (84/2510) were malaria positive. Among all study participants, 0.88% (255/28973) malaria positives were afebrile and 0.29% (84/28973) were febrile individuals. The 75.2% (255/339) of all malaria positives were afebrile. Of the total afebrile malaria cases, 10.2% (26/255) were under-five children and 89.8% (229/255) were above 5 years of age. Conclusion: The 1.17% malaria prevalence that ranges 0 to 4% in some districts by rapid diagnostic tests should be given due consideration by the elimination program. Especially the higher prevalence of afebrile individuals (0.88%) in these transmission settings indicates there may be sustaining hidden transmission. Therefore, active case detection with more sensitive diagnostic techniques than this conventional method is suggested to know more real magnitude of residual malaria in the elimination targeted low transmission areas and break the chain of transmission.

scholarly journals COMPARISON BETWEEN MICROSCOPY AND RAPID DIAGNOSTIC TESTS IN DIAGNOSIS OF MALARIA AT A TERTIARY CARE MEDICAL INSTITUTION IN UTTARAKHAND (A 3-YEAR STUDY)

2018 ◽  
Vol 11 (2) ◽  
pp. 94 ◽  
Author(s):  
Pratima Gupta ◽  
Priyanka Gupta ◽  
Shalinee Rao ◽  
Neha Singh ◽  
Deepjyoti Kalita
Keyword(s):  
Predictive Value ◽  
Diagnostic Tests ◽  
Tertiary Care ◽  
Screening Method ◽  
Malaria Diagnosis ◽  
Peripheral Blood Smear ◽  
Rapid Diagnostic Tests ◽  
Screening Methods ◽  
Suitable Alternative ◽  
Malaria Antigen

 Objectives: Malaria is one of the most prevalent parasitic diseases all over the world including India. Although the microscopic study of stained peripheral blood smear (PBS) is a gold standard of malaria diagnosis due to some subjective errors, rapid diagnostic tests (RDTs) can be a suitable alternative. This study was conducted to estimate the prevalence and demographic details of malaria cases along with a comparison between the two most common screening methods: PBS and RDTs.Methods: Demographic profile, the prevalence of malaria in this region of Uttarakhand and evaluation of efficacy of RDT as a screening method was performed. Analysis of PBS microscopy for malaria parasites was performed and compared with immunochromatography based RDT over a duration of 3 years.Results: Out of total 2982 clinically suspected patients of malaria, 132 were found to be positive by either of the two methods. Prevalence of malaria was 4.4% in our study. Plasmodium vivax was the predominant species isolated (95%). Males outnumbered females with a ratio of 2.1:1. The most common age group affected was 30–49 years. Sensitivity and specificity of RDT was found to be 91.8% and 93.8%, respectively. Positive predictive value and negative predictive value were found to be 97.8% and 98.9%, respectively.Conclusion: We conclude that Uttarakhand is a low prevalence area for Malaria and the RDT based on malaria antigen (whole blood) method is as specific and sensitive as the traditional PBS microscopy. Thus, it can be used as an alternative to PBS microscopy.

At risk drinking among general practice attenders: validation of the CAGE questionnaire

1986 ◽  
Vol 16 (1) ◽  
pp. 213-217 ◽  
Author(s):  
Michael King
Keyword(s):  
At Risk ◽  
General Practice ◽  
Positive Predictive Value ◽  
Predictive Value ◽  
Health Centre ◽  
London Health ◽  
Cage Questionnaire

SynopsisSynopsis The CAGE questionnaire was used to screen for at risk drinking among attenders to an inner London health centre. The CAGE functioned most effectively at a cut-off point of two or more affirmative replies, with a sensitivity of 84%, a specificity of 95% and a positive predictive value of 45%. The usefulness of this instrument for screening in general practice is discussed.

scholarly journals PREDICTIVE VALUE OF SMELL AND TASTE TEST VS PCR-RT SARS-COV-2 AND RAPID DIAGNOSTIC TESTS IN THE DIAGNOSIS OF INFECTION BY COVID-19. A PROSPECTIVE MULTI-CENTRIC STUDY.

2020 ◽  
Author(s):  
Rosalinda Pieruzzini ◽  
Carlos Ayala ◽  
Jose Navas ◽  
Wilneg Carolina Rodriguez ◽  
Nathalia Parra ◽  
...  
Keyword(s):  
Predictive Value ◽  
Diagnostic Tests ◽  
Rapid Diagnostic Tests ◽  
Variable Degree ◽  
Rt Pcr ◽  
Taste Test ◽  
Taste Disorders ◽  
Coronavirus Infection ◽  
Diagnosis Of Infection

There is a relationship between smell and taste disturbances and coronavirus infection. These symptoms have been considered the best predictor of coronavirus infection, for this reason, it was decided to evaluate the predictive value of the smell and taste test and its association with the results of SARS-CoV-2 PCR-RT and rapid diagnostic tests. in the diagnosis of pathology. Methodology: 248 patients divided into 3 groups: asymptomatic, symptomatic without chemosensory disorders, and chemosensory disorders alone. All of them underwent SARS-CoV-2 PCR-RT, a rapid diagnostic test and a test of Venezuelan smell and basic taste at the beginning. Weekly follow-up with smell and taste test and SARS-CoV-2 PCR-RT until recovery. Results: 20.56% of patients had smell and taste disorders to a variable degree and were positive by SARS-CoV-PCR-RT. 2.15.3% of patients with chemosensory disorders were negative for COVID-19. The positive predictive value of the smell and taste test was 57.3; Sensitivity 41.13% and specificity 69.35%. There were no statistically significant differences by age, sex and chemosensory disorders. The predominant chemosensory disorder was the combination of mild hyposmia and hypogeusia and appeared in the company of other symptoms. Recovery occurred in an average of 8.5 days, asynchronously with the SARS-CoV-2 RT-PCR negativization, which occurred up to more than 15 days after the senses recovered. Maximum time of negativization of the RT-PCR of 34 days. Conclusion: chemosensory disorders are a symptom and / or sign of coronavirus disease but cannot be considered as predictors of said disease in this population studied. The gold standard remains the SARS-CoV-2 PCR-RT test. Rapid diagnostic tests should be used for follow-up. Recommendations: it is necessary to expand the sample, include routine psychophysical smell and taste tests to screen cases and take race and virus mutations into consideration to explain behavior in certain populations. Key words: Smell, taste, coronavirus, test, diagnosis.

scholarly journals Comparison between Invasive & Non-Invasive Diagnostic Evaluation of Tuberculous Peritonitis In Our Prospective

2016 ◽  
Vol 27 (2) ◽  
pp. 20-22
Author(s):  
Md Naushad Ali ◽  
Rehana Parvin ◽  
Md Abul Kalam Azad ◽  
AKM Mazharul Islam
Keyword(s):  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Diagnostic Test ◽  
Predictive Value ◽  
Diagnostic Evaluation ◽  
Ca 125 ◽  
Histopathological Diagnosis ◽  
Peritoneal Tuberculosis ◽  
College Hospital ◽  
Non Invasive

This cross sectional study was carried out in the department of gastroenterology, Rangpur Medical College Hospital, Rangpur from January 2014 to July 2014 to compare between Invasive & Non-Invasive Diagnostic Evaluation of Tuberculosis Peritonitis In our prospective in clinically suspected patients. Total 30 patients (age 39.69±21.26, 18M/12F) with clinical suspicion of peritoneal tuberculosis were included in this study after analyzing selection criteria. Laparoscopic peritoneal biopsy with 'histopathological' diagnosis was considered as gold standard against which accuracies non-invasive test of two biomarkers (ADA & CA-125) were compared. Cut off value of ADA and CA-125 is 24 U/l, 35 U/ml respectively. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of ADA as a diagnostic modality in peritoneal tuberculosis were 87.5%, 83.33%, 95.45%, 62.5% and 86.67% respectively whereas CA-125 was found to have 83.33% sensitivity, 50% specificity, 86.9% positive predictive value, 42.85% negative predictive value and 76.6% accuracy. Both biomarkers were simple, non-invasive, rapid and relatively cheap diagnostic test whereas laparoscopy was an invasive procedure, costly & requires trained staff and not without risk and also not feasible in the entire centre in our country. So ascitic fluid ADA and serum CA-125 was important non-invasive diagnostic test for peritoneal tuberculosis.Medicine Today 2015 Vol.27(2): 20-22

scholarly journals Platelet count splenic diameter ratio as predictor for esophageal varices in patients with cirrhosis: a diagnostic evaluation study

2019 ◽  
Vol 7 (12) ◽  
pp. 4535
Author(s):  
Sunil Mathew ◽  
Sachin Chacko ◽  
Tomy Philip ◽  
R. N. Sharma ◽  
Kanniyan Binub
Keyword(s):  
Platelet Count ◽  
Positive Predictive Value ◽  
Esophageal Varices ◽  
Predictive Value ◽  
Evaluation Study ◽  
Diameter Ratio ◽  
Diagnostic Evaluation ◽  
Esophageal Variceal ◽  
Esophageal Variceal Bleeding ◽  
Non Invasive

Background: Esophageal variceal bleeding is one among the common complication of cirrhosis which is fatal. Latest studies are focusing more on using non-invasive techniques to classify cirrhotic patients according to their risk of having varices. The platelet count-splenic diameter ratio is considered as one such parameter and is used in predicting esophageal varices in patients with cirrhosis. Objectives of the study was to assess the utility of platelet count-splenic diameter ratio as a useful non- invasive parameter in predicting the presence/ absence /size of esophageal varices in patients with cirrhosis.Methods: Diagnostic evaluation study was done in a tertiary hospital of Kerala state India. 93 adults above the age of 18 yrs with diagnosis of cirrhosis was selected and detailed history, physical, systemic examination and imaging was done. The degree of correlation between platelet count-splenic size ratio and the presence/absence/size of esophageal varices was studied along with its utility as an independent non- invasive marker. Frequency was expressed in percentages.Results: Best cut-off for prediction of esophageal varices Grade 1 was platelet count/spleen diameter ratio of 954, which had Specificity of 85.7% and Positive predictive value of 94.1% Cut-off for prediction of Grade 2 esophageal varices was platelet count/spleen diameter ratio of 916 which had a Sensitivity of 78.9%, Specificity of 88.9%. Whereas cut-off for prediction of Grade 3 esophageal varices was a ratio of 899 which had a high Sensitivity of 88% and Negative predictive value of 93.6 % but Specificity was only 64.7% and Positive predictive value of 47.8% only.Conclusions: The platelet count splenic diameter ratio is accurate to be used as screening tool to predict the presence of Grade 2 Esophageal varices in Patients with Cirrhosis. More studies need to be done around the globe for more evidence.

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