A Molecular Investigation of Malaria Infections From High-Transmission Areas of Southern Togo Reveals Different Species of Plasmodium Parasites

Malaria particularly burdens people in poor and neglected settings across the tropics of Africa. Meanwhile, a large proportion of the Togo population have poor understanding of malaria epidemiology and parasites. This study carried out a molecular survey of malaria cases in southern Togo during 2017–2019. We estimated Plasmodium species infection rates and microscopic examination compliance with nested PCR results. Sensitivity and specificity analyses were performed in conjunction with predictive values. Also, phylogenetic characterization of species of malaria parasites was assessed. Plasmodium genus-specific nested PCR identified 565 positive cases including 536/611 (87.8%) confirmed cases from the microscopy-positive group and 29/199 (14.6%) diagnosed malaria cases from the microscopy-negative group. Our findings revealed a disease prevalence (69.8%) higher than that reported (25.5–55.1%) for the country. The diagnostic test had 94.9% sensitivity and 69.4% specificity, i.e., it missed 120 of the people who had malaria and about one-third of the people tested positive for the disease, which they did not have, respectively. In conjunction, the test showed 87.7% positive predictive value and 85.4% negative predictive value, which, from a clinical perspective, indicates the chance that a person with a positive diagnostic test truly has the disease and the probability that a person with a negative test does not have the disease, respectively. Further species-specific nested PCR followed by analysis of gene sequences confirmed species of malaria parasites and indicated infection rates for Plasmodium falciparum (Pf), 95.5% (540/565); P. ovale (Po), 0.5% (3/565); and P. malariae (Pm), 0.4% (2/565). In addition, 20 cases were coinfection cases of Pf-Po (15/565) and Pf-Pm (5/565). This study publicly reports, for the first time, a molecular survey of malaria cases in Togo and reveals the presence of other malaria parasites (Po and Pm) other than Pf. These findings might provide answers to some basic questions on the malaria scenario and, knowledge gained could help with intervention deployment for effective malaria control in Togo.

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Does exposure to simulated patient cases improve accuracy of clinicians’ predictive value estimates of diagnostic test results? A within-subjects experiment at St Michael’s Hospital, Toronto, Canada

BMJ Open ◽

10.1136/bmjopen-2017-019241 ◽

2018 ◽

Vol 8 (2) ◽

pp. e019241 ◽

Cited By ~ 3

Author(s):

Bonnie Armstrong ◽

Julia Spaniol ◽

Nav Persaud

Keyword(s):

Diagnostic Test ◽

Predictive Value ◽

Simulated Patient ◽

Estimation Accuracy ◽

Absolute Difference ◽

Accurate Estimation ◽

Estimation Errors ◽

Predictive Values ◽

Within Subjects ◽

Test Result

ObjectiveClinicians often overestimate the probability of a disease given a positive test result (positive predictive value; PPV) and the probability of no disease given a negative test result (negative predictive value; NPV). The purpose of this study was to investigate whether experiencing simulated patient cases (ie, an ‘experience format’) would promote more accurate PPV and NPV estimates compared with a numerical format.DesignParticipants were presented with information about three diagnostic tests for the same fictitious disease and were asked to estimate the PPV and NPV of each test. Tests varied with respect to sensitivity and specificity. Information about each test was presented once in the numerical format and once in the experience format. The study used a 2 (format: numerical vs experience) × 3 (diagnostic test: gold standard vs low sensitivity vs low specificity) within-subjects design.SettingThe study was completed online, via Qualtrics (Provo, Utah, USA).Participants50 physicians (12 clinicians and 38 residents) from the Department of Family and Community Medicine at St Michael’s Hospital in Toronto, Canada, completed the study. All participants had completed at least 1 year of residency.ResultsEstimation accuracy was quantified by the mean absolute error (MAE; absolute difference between estimate and true predictive value). PPV estimation errors were larger in the numerical format (MAE=32.6%, 95% CI 26.8% to 38.4%) compared with the experience format (MAE=15.9%, 95% CI 11.8% to 20.0%,d=0.697, P<0.001). Likewise, NPV estimation errors were larger in the numerical format (MAE=24.4%, 95% CI 14.5% to 34.3%) than in the experience format (MAE=11.0%, 95% CI 6.5% to 15.5%,d=0.303, P=0.015).ConclusionsExposure to simulated patient cases promotes accurate estimation of predictive values in clinicians. This finding carries implications for diagnostic training and practice.

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Mentorship on malaria microscopy diagnostic service in Ethiopia: Baseline competency of microscopists and performance of health facilities

10.21203/rs.3.rs-87991/v2 ◽

2021 ◽

Author(s):

Bokretsion Gidey ◽

Desalegn Nega ◽

Adugna Abera ◽

Abnet Abebe ◽

Sindew Mekasha ◽

...

Keyword(s):

Sensitivity And Specificity ◽

Predictive Value ◽

False Negative ◽

Malaria Diagnosis ◽

Health Facilities ◽

Malaria Parasites ◽

Cross Sectional ◽

Predictive Values ◽

Microscopic Diagnosis ◽

Malaria Microscopy

Abstract Background: In Ethiopia, malaria cases are declining as a result of proven interventions and in 2017, the country launched a malaria elimination strategy in targeted settings. Accurate malaria diagnosis and prompt treatment are the key components of the strategy to prevent morbidity and stop the continuation of transmission. However, the quality of microscopic diagnosis in general is deteriorating as malaria burden declines. Therefore, this study was carried out to evaluate the competency of microscopists and the performance of health facilities on malaria microscopic diagnosis.Methods: A cross-sectional study was conducted from August 1st to September 30th, 2019 in nine regional states and one city administration. A standard checklist was used for on-site evaluation, archived patient slides were re-checked, and proficiency of microscopists was tested using WHO certified slides from the national slide bank at the Ethiopian Public Health Institute (EPHI). The strength of agreement, the sensitivity, the specificity, and the positive and negative predictive values were calculated.Results: In this study, 102 health facilities (84 health centers and 18 hospitals) were included; from which, 202 laboratory professionals participated. In slide re-checking, moderate agreement (Agreement: 76.0%; Kappa: 0.41) was observed between experts and microscopists on malaria detection in all health facilities. The sensitivity and specificity of routine slide reading and the re-checking results were 78.1% and 80.7%, respectively. Likewise, positive predictive value of 65.1% and negative predictive value of 88.8% were scored in the routine diagnosis. By panel testing, a substantial overall agreement (A: 91.8%; K: 0.79) was observed between microscopists and experts in detecting malaria parasites. The sensitivity and specificity in the detection of malaria parasites was 92.7% and 89.1%, respectively. Furthermore, in identifying species, a slight agreement (A: 57%; K: 0.18) was observed between microscopists and experts. Conclusion: The study found significant false positive and false negative results in routine microscopy on slide re-checking of Plasmodium parasites. Moreover, reduced grade in parasite species identification was reported on the panel tests. Therefore, implementing comprehensive malaria microscopy mentorship, in-service training, and supportive supervision are the key strategies to improve the overall performance of health facilities in malaria microscopy.

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Mentorship on malaria microscopy diagnostic service in Ethiopia: baseline competency of microscopists and performance of health facilities

Malaria Journal ◽

10.1186/s12936-021-03655-9 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Bokretsion Gidey ◽

Desalegn Nega ◽

Adugna Abera ◽

Abnet Abebe ◽

Sindew Mekasha ◽

...

Keyword(s):

Sensitivity And Specificity ◽

Predictive Value ◽

False Negative ◽

Malaria Diagnosis ◽

Health Facilities ◽

Malaria Parasites ◽

Cross Sectional ◽

Predictive Values ◽

Microscopic Diagnosis ◽

Malaria Microscopy

Abstract Background In Ethiopia, malaria cases are declining as a result of proven interventions, and in 2017 the country launched a malaria elimination strategy in targeted settings. Accurate malaria diagnosis and prompt treatment are the key components of the strategy to prevent morbidity and stop the continuation of transmission. However, the quality of microscopic diagnosis in general is deteriorating as malaria burden declines. This study was carried out to evaluate the competency of microscopists and the performance of health facilities on malaria microscopic diagnosis. Methods A cross-sectional study was conducted from 1 August to 30 September, 2019 in 9 regional states and one city administration. A standard checklist was used for on-site evaluation, archived patient slides were re-checked and proficiency of microscopists was tested using a WHO-certified set of slides from the national slide bank at the Ethiopian Public Health Institute (EPHI). The strength of agreement, sensitivity, specificity, and positive and negative predictive values were calculated. Results In this study, 102 health facilities (84 health centres and 18 hospitals) were included, from which 202 laboratory professionals participated. In slide re-checking, moderate agreement (agreement (A): 76.0%; Kappa (K): 0.41) was observed between experts and microscopists on malaria detection in all health facilities. The sensitivity and specificity of routine slide reading and the re-checking results were 78.1 and 80.7%, respectively. Likewise, positive predictive value of 65.1% and negative predictive value of 88.8% were scored in the routine diagnosis. By panel testing, a substantial overall agreement (A: 91.8%; K: 0.79) was observed between microscopists and experts in detecting malaria parasites. The sensitivity and specificity in the detection of malaria parasites was 92.7 and 89.1%, respectively. In identifying species, a slight agreement (A: 57%; K: 0.18) was observed between microscopists and experts. Conclusion The study found significant false positive and false negative results in routine microscopy on slide re-checking of Plasmodium parasites. Moreover, reduced grade in parasite species identification was reported on the panel tests. Implementing comprehensive malaria microscopy mentorship, in-service training and supportive supervision are key strategies to improve the overall performance of health facilities in malaria microscopy.

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Mentorship on Malaria Microscopy Diagnostic Service in Ethiopia: Baseline Competency of Microscopists and Performance of Health Facilities

10.21203/rs.3.rs-87991/v1 ◽

2020 ◽

Author(s):

Bokretsion Gidey ◽

Desalegn Nega ◽

Adugna Abera ◽

Abnet Abebe ◽

Sindew Mekasha ◽

...

Keyword(s):

Sensitivity And Specificity ◽

Predictive Value ◽

False Negative ◽

Malaria Diagnosis ◽

Cross Sectional Study ◽

Health Facilities ◽

Malaria Parasites ◽

Cross Sectional ◽

Predictive Values ◽

Malaria Microscopy

Abstract Background: In Ethiopia, malaria case is declining as a result of proven interventions and the country launched malaria elimination strategy in targeted settings since 2017. Accurate malaria diagnosis and prompt treatment are the key components of the strategy to prevent morbidity and stop continuation of the transmission. However, the quality of microscopic diagnosis in general is deteriorating as malaria burden declines. Therefore, this study was carried out toevaluate the competency of microscopists and the performance of health facilities on malaria microscopic diagnosis.Methods: A cross-sectional study was conducted from August 01 to September 30, 2019 in nine Regional States and one city administration. A standard checklist was used for on-site evaluation, archived patient slides were re-checked and proficiency of microscopists was tested using WHO certified slides from national slide bank in public health institute. Strength of agreement, sensitivity, specificity and positive and negative predictive values were calculated.Results: In this study, 102 health facilities (84 health centers and 18 hospitals) were included; from which, 202 laboratory professionals participated. In slide re-checking, moderate agreement (Agreement: 76.0%; Kappa: 0.41) was observed between experts and microscopists on malaria detection in all health facilities. The sensitivity and specificity of routine slide reading and the rechecking results were 78.1% and 80.7%, respectively. Likewise, positive predictive value of 65.1% and negative predictive value of 88.8% were scored in the routine diagnosis. By panel testing, a substantial overall agreement (A: 91.8%; K: 0.79) was observed between microscopists and experts in detecting malaria parasites. The sensitivity and specificity in detection of malaria parasites was 92.7% and 89.1%, respectively. Furthermore, in identifying species, slight agreement (A: 57%; K: 0.18) was observed between microscopists and experts. Conclusion: The study found significant false positive and false negative results in routine microscopy on slide re-checking of Plasmodium parasites. Moreover, reduced grade in parasite species identification was reported on the panel tests. Therefore, implementing comprehensive malaria microscopy mentorship, in-service training and supportive supervision are the key strategies to improve the overall performance of health facilities in malaria microscopy.

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Mentorship on malaria microscopy diagnostic service in Ethiopia: Baseline competency of microscopists and performance of health facilities

10.21203/rs.3.rs-87991/v3 ◽

2021 ◽

Author(s):

Bokretsion Gidey ◽

Desalegn Nega ◽

Adugna Abera ◽

Abnet Abebe ◽

Sindew Mekasha ◽

...

Keyword(s):

Sensitivity And Specificity ◽

Predictive Value ◽

False Negative ◽

Malaria Diagnosis ◽

Health Facilities ◽

Malaria Parasites ◽

Cross Sectional ◽

Predictive Values ◽

Microscopic Diagnosis ◽

Malaria Microscopy

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Predictive Value of Decreasing Antithrombin III in Deep-Vein Thrombosis

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650103 ◽

1980 ◽

Vol 44 (03) ◽

pp. 135-137 ◽

Cited By ~ 2

Author(s):

Thorkild Lund Andreasen

Keyword(s):

Deep Vein Thrombosis ◽

Predictive Value ◽

Coronary Care Unit ◽

Antithrombin Iii ◽

Predictive Values ◽

Vein Thrombosis ◽

At Iii ◽

Coronary Care ◽

Time Of Admission ◽

Deep Vein

SummaryAntithrombin III (At-III) was measured at the time of admission and two days later in 131 patients laid up in a coronary care unit. The patients were examined for deep-vein thrombosis (DVT) clinically and by means of 125I-fibrinogen scanning. 19 patients developed DVT. In 11 subjects with and 25 without DVT At-III decreased more than 10%. And in 7 with and 17 without DVT At-III decreased more than 15%. One person with DVT had subnormal At-III. By using decrease of At-III or subnormal initial At-III to predict DVT the following predictive value (PV) were found. Decrease ≤ 10%, PV pos.= 0.32 and PV neg. = 0.93. Decrease ≤ 15%, PV pos. = 0.32 and PV neg. = 0.90. The positive predictive values obtained were too low to let decreasing At-III give occasion for prophylactic anticoagulant treatment.

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Presepsin - New Marker of Sepsis Romanian Neonatal Intensive Care Unit Experience

Revista de Chimie ◽

10.37358/rc.19.8.7475 ◽

2019 ◽

Vol 70 (8) ◽

pp. 3008-3013

Author(s):

Silvia Maria Stoicescu ◽

Ramona Mohora ◽

Monica Luminos ◽

Madalina Maria Merisescu ◽

Gheorghita Jugulete ◽

...

Keyword(s):

Intensive Care Unit ◽

Intensive Care ◽

Neonatal Intensive Care Unit ◽

Neonatal Sepsis ◽

Predictive Value ◽

Neonatal Intensive Care ◽

Complete Blood Count ◽

Clinical Manifestations ◽

Receiver Operating Curve ◽

Predictive Values

Difficulties in establishing the onset of neonatal sepsis has directed the medical research in recent years to the possibility of identifying early biological markers of diagnosis. Overdiagnosing neonatal sepsis leads to a higher rate and duration in the usage of antibiotics in the Neonatal Intensive Care Unit (NICU), which in term leads to a rise in bacterial resistance, antibiotherapy complications, duration of hospitalization and costs.Concomitant analysis of CRP (C Reactive Protein), procalcitonin, complete blood count, presepsin in newborn babies with suspicion of early or late neonatal sepsis. Presepsin sensibility and specificity in diagnosing neonatal sepsis. The study group consists of newborns admitted to Polizu Neonatology Clinic between 15th February- 15th July 2017, with suspected neonatal sepsis. We analyzed: clinical manifestations and biochemical markers values used for diagnosis of sepsis, namely the value of CRP, presepsin and procalcitonin on the onset day of the disease and later, according to evolution. CRP values may be influenced by clinical pathology. Procalcitonin values were mainly influenced by the presence of jaundice. Presepsin is the biochemical marker with the fastest predictive values of positive infection. Presepsin can be a useful tool for early diagnosis of neonatal sepsis and can guide the antibiotic treatment. Presepsin value is significantly higher in neonatal sepsis compared to healthy newborns (939 vs 368 ng/mL, p [ 0.0001); area under receiver operating curve (AUC) for presepsine was 0.931 (95% confidence interval 0.86-1.0). PSP has a greater sensibility and specificity compared to classical sepsis markers, CRP and PCT respectively (AUC 0.931 vs 0.857 vs 0.819, p [ 0.001). The cut off value for presepsin was established at 538 ng/mLwith a sensibility of 79.5% and a specificity of 87.2 %. The positive predictive value (PPV) is 83.8 % and negative predictive value (NPV) is 83.3%.

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Diagnosis of tuberculosis pleurisy with three endoscopic features via pleuroscopy

Therapeutic Advances in Respiratory Disease ◽

10.1177/1753466621989532 ◽

2021 ◽

Vol 15 ◽

pp. 175346662198953

Author(s):

Chung-Shu Lee ◽

Shih-Hong Li ◽

Chih-Hao Chang ◽

Fu-Tsai Chung ◽

Li-Chung Chiu ◽

...

Keyword(s):

Pleural Effusion ◽

Predictive Value ◽

Image Interpretation ◽

Discrete Distribution ◽

Unknown Origin ◽

Tertiary Hospital ◽

Public Health Campaign ◽

Health Campaign ◽

Predictive Values ◽

Characteristic Features

Background: Tuberculosis (TB) is a constant threat even with a worldwide active public health campaign. Diagnosis of TB pleurisy is challenging in the case of pleural effusion of unknown origin after aspiration analysis. The study was designed to demonstrate a simple image interpretation technique to differentiate TB pleurisy from non-TB pleurisy using semi-rigid pleuroscopy. Methods: The study retrospectively enrolled 117 patients who underwent semi-rigid pleuroscopy from April 2016 to August 2018 in a tertiary hospital. We analyzed the possibility of TB pleurisy using three simple pleuroscopic images via semi-rigid pleuroscopy. Results: Among 117 patients, 28 patients (23.9%) were diagnosed with TB pleurisy. Sago-like nodules/micronodules, adhesion, and discrete distribution were noted in 20 (71.4%), 20 (71.4%), and 19 (67.9%) patients with TB pleurisy, respectively. Sago-like nodules/micronodules, adhesion, and discrete distribution were noted in six (6.7%), 37 (41.6%), and no (0.0%) patients with non-TB pleurisy, respectively. The positive and negative predictive values of any two out of three pleuroscopic patterns for TB pleurisy were 100.0% and 93.7%, respectively. Conclusions: A high positive predictive value for TB pleurisy was demonstrated by the presence of any two out of the three characteristic features. Absence of all three features had an excellent negative predictive value for TB pleurisy. Our diagnostic criteria reconfirm that pleuroscopic images can be used as predictors for TB pleurisy in patients with undiagnosed pleural effusion. The reviews of this paper are available via the supplementary material section.

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Toxoplasma gondii in Sheep and Goats from Central Iran

BMC Research Notes ◽

10.1186/s13104-021-05465-3 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Mojtaba Bahreh ◽

Bahador Hajimohammadi ◽

Gilda Eslami

Keyword(s):

Toxoplasma Gondii ◽

Dna Extraction ◽

Infection Rate ◽

Nested Pcr ◽

Prevention Programs ◽

Central Iran ◽

Infection Rates ◽

Sheep And Goats ◽

One Year ◽

Undercooked Meat

Abstract Objective Toxoplasmosis, caused by Toxoplasma gondii, infects humans by consuming infected raw or undercooked meat and foods harboring mature oocysts. In this study, we assessed the prevalence of T. gondii in sheep and goats coming from central Iran. After completing the questionnaire, about one gram of liver or diaphragm tissue was taken as a sample from 90 sheep and 90 goats slaughtered in Yazd Province and stored at – 20 ºC. DNA extraction was done, and then T. gondii was detected using nested PCR. Results This study indicated that the prevalence of T. gondii in all slaughtered animals was 11.6% (21 of 180), including 14.4% (13/90) in sheep and 8.8% (8/90) in goats. The infection rates in liver and diaphragm samples were 12.2% (11/90) and 11.1% (10/90), respectively (p = 0.8163). The infection rate in animals older than one was 16.3% (15/92), and it was 6.8% (6/88) in animals under one year of age. Therefore, no significant differences were found (p = 0.475). Infection rates were 19.5% (18/92) in males and 3.4% (3/88) in females (p = 0.0007). In conclusion, the infection rates of toxoplasmosis in livestock in this area are almost high, and therefore, it is necessary to design appropriate prevention programs to control the disease.

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Predictive value of time-variant color-coded multiphase CT angiography (mCTA) regarding clinical outcome of acute ischemic stroke: in comparison with conventional mCTA and CT perfusion

Acta Radiologica ◽

10.1177/0284185120981770 ◽

2020 ◽

pp. 028418512098177

Author(s):

Yu Lin ◽

Nannan Kang ◽

Jianghe Kang ◽

Shaomao Lv ◽

Jinan Wang

Keyword(s):

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Predictive Value ◽

Ct Perfusion ◽

Roc Curves ◽

Multivariate Logistic Regression Model ◽

Infarct Core ◽

Predictive Values ◽

Significant Difference ◽

Core Volume

Background Color-coded multiphase computed tomography angiography (mCTA) can provide time-variant blood flow information of collateral circulation for acute ischemic stroke (AIS). Purpose To compare the predictive values of color-coded mCTA, conventional mCTA, and CT perfusion (CTP) for the clinical outcomes of patients with AIS. Material and Methods Consecutive patients with anterior circulation AIS were retrospectively reviewed at our center. Baseline collateral scores of color-coded mCTA and conventional mCTA were assessed by a 6-point scale. The reliabilities between junior and senior observers were assessed by weighted Kappa coefficients. Receiver operating characteristic (ROC) curves and multivariate logistic regression model were applied to evaluate the predictive capabilities of color-coded mCTA and conventional mCTA scores, and CTP parameters (hypoperfusion and infarct core volume) for a favorable outcome of AIS. Results A total of 138 patients (including 70 cases of good outcomes) were included in our study. Patients with favorable prognoses were correlated with better collateral circulations on both color-coded and conventional mCTA, and smaller hypoperfusion and infarct core volume (all P < 0.05) on CTP. ROC curves revealed no significant difference between the predictive capability of color-coded and conventional mCTA ( P = 0.427). The predictive value of CTP parameters tended to be inferior to that of color-coded mCTA score (all P < 0.001). Both junior and senior observers had consistently excellent performances (κ = 0.89) when analyzing color-coded mCTA maps. Conclusion Color-coded mCTA provides prognostic information of patients with AIS equivalent to or better than that of conventional mCTA and CTP. Junior radiologists can reach high diagnostic accuracy when interpreting color-coded mCTA images.

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