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PLoS Medicine Jun 2007The global tuberculosis epidemic results in nearly 2 million deaths and 9 million new cases of the disease a year. The vast majority of tuberculosis patients live in... (Comparative Study)
Comparative Study Meta-Analysis Review
BACKGROUND
The global tuberculosis epidemic results in nearly 2 million deaths and 9 million new cases of the disease a year. The vast majority of tuberculosis patients live in developing countries, where the diagnosis of tuberculosis relies on the identification of acid-fast bacilli on unprocessed sputum smears using conventional light microscopy. Microscopy has high specificity in tuberculosis-endemic countries, but modest sensitivity which varies among laboratories (range 20% to 80%). Moreover, the sensitivity is poor for paucibacillary disease (e.g., pediatric and HIV-associated tuberculosis). Thus, the development of rapid and accurate new diagnostic tools is imperative. Immune-based tests are potentially suitable for use in low-income countries as some test formats can be performed at the point of care without laboratory equipment. Currently, dozens of distinct commercial antibody detection tests are sold in developing countries. The question is "do they work?"
METHODS AND FINDINGS
We conducted a systematic review to assess the accuracy of commercial antibody detection tests for the diagnosis of pulmonary tuberculosis. Studies from all countries using culture and/or microscopy smear for confirmation of pulmonary tuberculosis were eligible. Studies with fewer than 50 participants (25 patients and 25 control participants) were excluded. In a comprehensive search, we identified 68 studies. The results demonstrate that (1) overall, commercial tests vary widely in performance; (2) sensitivity is higher in smear-positive than smear-negative samples; (3) in studies of smear-positive patients, Anda-TB IgG by enzyme-linked immunosorbent assay shows limited sensitivity (range 63% to 85%) and inconsistent specificity (range 73% to 100%); (4) specificity is higher in healthy volunteers than in patients in whom tuberculosis disease is initially suspected and subsequently ruled out; and (5) there are insufficient data to determine the accuracy of most commercial tests in smear microscopy-negative patients, as well as their performance in children or persons with HIV infection.
CONCLUSIONS
None of the commercial tests evaluated perform well enough to replace sputum smear microscopy. Thus, these tests have little or no role in the diagnosis of pulmonary tuberculosis. Lack of methodological rigor in these studies was identified as a concern. It will be important to review the basic science literature evaluating serological tests for the diagnosis of pulmonary tuberculosis to determine whether useful antigens have been described but their potential has not been fully exploited. Activities leading to the discovery of new antigens with immunodiagnostic potential need to be intensified.
Topics: Adult; Agglutination Tests; Antibodies, Bacterial; Blood Preservation; Blotting, Western; Child; Comorbidity; Developing Countries; Enzyme-Linked Immunosorbent Assay; HIV Infections; Humans; Immunoglobulin G; Kaolin; Mycobacterium tuberculosis; Predictive Value of Tests; Reagent Kits, Diagnostic; Reproducibility of Results; Research Design; Sensitivity and Specificity; Sputum; Tuberculosis, Pulmonary
PubMed: 17564490
DOI: 10.1371/journal.pmed.0040202 -
African Health Sciences Mar 2020is encapsulated opportunistic yeast that causes life threatening meningoencephalitis of patients with human immunodeficiency virus (HIV). The magnitude of among HIV... (Meta-Analysis)
Meta-Analysis
BACKGROUND
is encapsulated opportunistic yeast that causes life threatening meningoencephalitis of patients with human immunodeficiency virus (HIV). The magnitude of among HIV patients varies from 1-10% in Western countries as opposed to almost a one third of HIV-infected individuals in sub-Saharan Africa where it is associated with high mortality.
METHODOLOGY
By using key terms " among HIV patients in sub-saharan Africa countries", articles that published in different journals from 2010-2017 searched on Pub-Med and Google scholar database. Those freely accessible and included the prevalence of in the result section, their PDF file was downloaded and the result extracted manually and presented in table. Articles that did not report the prevalence of , with a study design otherthan cross sectional, or a sample size less than 100, and those duplicated in the same study area and period by the same authors were excluded. The article selection followed the PRISMA guidelines and meta- analysis was performed using OpenMeta(analyst).
RESULTS
The overall pooled magnitude of among HIV patients in sub saharan African countries was 8.3% (95%CI 6.1-10.5%). The highest prevalence was from Uganda (19%) and the least was from Ethiopia at 1.6%. There was 87.2 % of substantial heterogeneity among the studies with p-value<0.001. The symmetry ofthe forest plot showed that there was little publication bias. The most commonly used method for diagnosis of was lateral flow assay and latex agglutination test and culture was the least method employed.
CONCLUSION
The overall pooled magnitude of high among HIV patients in sub-Saharan African countries. The studies showed substantial heterogeneity, and little publication bias. Most of the studies relied on LFA & LA that showed the scarcity of facilities for fungal culture. Therefore, paying attention to screening HIV patients; those with signs and symptoms of meningitis may help to reduce the loss of HIV patients.
Topics: AIDS-Related Opportunistic Infections; Africa; Anti-HIV Agents; Cryptococcosis; Ethiopia; Female; HIV Infections; Humans; Male; Meningoencephalitis; Prevalence; Uganda
PubMed: 33402899
DOI: 10.4314/ahs.v20i1.16 -
Seminars in Arthritis and Rheumatism Jun 2015Systemic lupus erythematosus (SLE) is an autoimmune disease that may present manifestations that resemble other diseases. Visceral leishmaniasis (VL) is a parasitic... (Review)
Review
OBJECTIVE
Systemic lupus erythematosus (SLE) is an autoimmune disease that may present manifestations that resemble other diseases. Visceral leishmaniasis (VL) is a parasitic infection whose hallmarks may mimic SLE symptoms. Here, we report a case series and evaluate the published, scientific evidence of the relationship between SLE and VL infection.
METHODS
To assess original studies reporting cases of VL-infected patients presenting manifestations that are capable of leading to inappropriate suspicions of SLE or mimicking an SLE flare, we performed an extensive search in several scientific databases (MEDLINE, LILACS, SciELO, and Scopus). Two authors independently screened all citations and abstracts identified by the search strategy to identify eligible studies. Secondary references were additionally obtained from the selected articles.
RESULTS
The literature search identified 53 eligible studies, but only 17 articles met our criteria. Among these, 10 lupus patients with VL mimicking an SLE flare and 18 cases of VL leading to unappropriated suspicions of SLE were described. The most common manifestations in patients infected with VL were intermittent fever, pancytopenia, visceromegaly, and increased serum level of acute phase reactants. The most frequent autoantibodies were antinuclear antibodies, rheumatoid factor, and direct Coombs' test.
CONCLUSION
In endemic areas for VL, the diagnosis of SLE or its exacerbation may be a clinical dilemma. Hepatosplenomegaly or isolated splenomegaly was identified in the majority of the reported cases where VL occurred, leading to unappropriated suspicions of SLE or mimicking an SLE flare. Furthermore, the lack of response to steroids, the normal levels of complement proteins C3 and C4, and the increased level of transaminases suggest a possible infectious origin.
Topics: Adolescent; Adult; Antibodies, Antinuclear; Coombs Test; Diagnosis, Differential; Female; Fever; Humans; Leishmaniasis, Visceral; Lupus Erythematosus, Systemic; Pancytopenia; Rheumatoid Factor
PubMed: 25704907
DOI: 10.1016/j.semarthrit.2014.12.004 -
European Journal of Obstetrics,... Mar 2010Evans' syndrome, the coexistence of immune thrombocytopenia (ITP) with autoimmune haemolytic anaemia (AIHA), is rare in pregnancy, with a few published cases. Concerns... (Review)
Review
Evans' syndrome, the coexistence of immune thrombocytopenia (ITP) with autoimmune haemolytic anaemia (AIHA), is rare in pregnancy, with a few published cases. Concerns about the teratogenic effect of pharmacological agents used in the management of Evans' syndrome limit the treatment options in pregnancy. In this paper we performed a systematic review of the literature of all published cases with Evans' syndrome in pregnancy and we report two new cases. The review was performed by searching the electronic databases PubMed, EMBASE, Cochrane Library and Google scholar up to the end of December 2008. The selection criteria were Evans' syndrome in pregnancy; autoimmune haemolytic anaemia; immune thrombocytopenia. Thirteen papers reporting 14 pregnancies in women with Evans' syndrome have been published: 7 papers are written in English. Evans' syndrome can be diagnosed with a full blood count, film and Coombs testing. It runs a more benign course in pregnancy than in non-pregnant state (notably neutropenia does not occur) and very often resolves post-delivery. The fetal outcome may be less favourable: a minority of fetuses are affected by transplacental passage of antibody and have a significant morbidity and mortality. With appropriate treatment, women with Evans' syndrome can have successful pregnancies, with a good response to conventional treatment. More detailed studies of Evans' syndrome in pregnancy, especially of fetal outcome, are required.
Topics: Adult; Anemia, Hemolytic, Autoimmune; Coombs Test; Female; Humans; Immunoglobulin G; Prednisolone; Pregnancy; Pregnancy Complications, Hematologic; Pregnancy Outcome; Purpura, Thrombocytopenic, Idiopathic; Syndrome; Treatment Outcome
PubMed: 20031296
DOI: 10.1016/j.ejogrb.2009.11.022 -
Parasitology International Oct 2018Visualization of amastigotes in lymph nodes, bone marrow, and other tissues samples remains the gold standard method for the diagnosis of visceral leishmaniasis (VL) in... (Meta-Analysis)
Meta-Analysis
Visualization of amastigotes in lymph nodes, bone marrow, and other tissues samples remains the gold standard method for the diagnosis of visceral leishmaniasis (VL) in humans. This gold standard diagnostic method uses a technically challenging microscopy procedure that is often not accessible in many places in the world where VL is endemic. Here, we report the current systematic review and meta-analysis to evaluate whether urine is a reliable clinical sample for diagnosis of human VL. Data were extracted from ten available databases during the period from 2002 to 2017. Overall, 29 articles fulfilled the inclusion criteria and were used for data extraction in this systematic review. Most studies (72.4%) using urine specimens were reported from five countries: India 6 (20.7%), Iran 5 (17.2%), Bangladesh 4 (13.8%), Japan 3 (10.3%) and Spain 3 (10.3%), respectively. The most common diagnostic tests performed on urine were Katex (62.1%), ELISA (24.1%), and the rK39 (17.2%) assays. In meta-analysis the sensitivity and specificity of the three most commonly used diagnostic assays were rK39 (97%; CI: 91-99; 98%;76-100), ELISA (91%; 82-95; 99%; CI: 94-100), and Katex (83%; 73-90; 98%; 98-100), suggesting that the rK39 assay provided the highest sensitivity and the ELISA assay provided the highest specificity for diagnosis of VL from urine samples. Our findings suggest that urine is a valuable clinical sample for the diagnosis of human VL, particularly in areas where the gold standard test for VL is not available.
Topics: Antigens, Protozoan; Enzyme-Linked Immunosorbent Assay; Humans; Latex Fixation Tests; Leishmania donovani; Leishmaniasis, Visceral; Molecular Diagnostic Techniques; Polymerase Chain Reaction; Protozoan Proteins; Reagent Kits, Diagnostic; Sensitivity and Specificity
PubMed: 29775824
DOI: 10.1016/j.parint.2018.05.008 -
Parasite (Paris, France) 2021Chronic infection with Toxoplasma gondii is attested by the detection of specific anti-Toxoplasma IgG. A wide panel of serologic methods is currently marketed, and the...
Chronic infection with Toxoplasma gondii is attested by the detection of specific anti-Toxoplasma IgG. A wide panel of serologic methods is currently marketed, and the most suitable method should be chosen according to the laboratory resources and the screened population. This systematic review of evaluation studies aimed at establishing an overview of the performances, i.e. sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of marketed anti-Toxoplasma IgG assays, and discussing their technical characteristics to guide further choice for routine diagnostic use. According to PRISMA guidelines, the search performed in PubMed and Web of Science databases recovered 826 studies, of which 17 were ultimately included. Twenty commercial anti-Toxoplasma IgG assays were evaluated, in comparison with an accepted reference method. Most of them were enzyme-immunoassays (EIAs, n = 12), followed by agglutination tests (n = 4), immunochromatographic tests (n = 3), and a Western-Blot assay (WB, n = 1). The mean sensitivity of IgG assays ranged from 89.7% to 100% for standard titers and from 13.4% to 99.2% for low IgG titers. A few studies pointed out the ability of some methods, especially WB to detect IgG early after primary infection. The specificity of IgG assays was generally high, ranging from 91.3% to 100%; and higher than 99% for most EIA assays. The PPV was not a discriminant indicator among methods, whereas significant disparities (87.5%-100%) were reported among NPVs, a key-parameter assessing the ability to definitively rule out a Toxoplasma infection in patients at-risk for opportunistic infections.
Topics: Antibodies, Protozoan; Blotting, Western; Enzyme-Linked Immunosorbent Assay; Humans; Immunoglobulin G; Immunoglobulin M; Sensitivity and Specificity; Toxoplasma; Toxoplasmosis
PubMed: 33904818
DOI: 10.1051/parasite/2021035 -
BMC Infectious Diseases Apr 2020Leptospirosis is a neglected zoonotic disease which is a major challenge for clinicians and public health professionals in tropical countries. The cytokine storm during...
BACKGROUND
Leptospirosis is a neglected zoonotic disease which is a major challenge for clinicians and public health professionals in tropical countries. The cytokine storm during the second (immune) phase is thought to be a major contributory factor for the leptospirosis disease severity. We aim to summarize evidence for cytokine response in leptospirosis at different clinical outcomes.
METHODS
A systematic review was carried out to examine the cytokine response in leptospirosis patients using relevant scientific databases. Reference lists of the selected articles were also screened. Quality of the selected studies was assessed by using the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies.
RESULTS
Of the 239 articles retrieved in the initial search, 18 studies fulfilled the selection criteria. India and Thailand have produced the highest number of studies (17% each, n = 3). The majority were comparative cross-sectional studies (72%, n = 13). Overall the quality of the selected studies was fair regardless of few drawbacks such as reporting of sample size and the lack of adjustment for confounders. Microscopic agglutination test (67% - 12/18) and enzyme-linked immunosorbent assay (50% - 9/18) were commonly used for the confirmation of leptospirosis and the measurement of cytokines respectively. IL-1b, IL-2, IL-4, IL-6, IL-8, IL-10 and TNF-α levels were found to be significantly higher in severe than in mild leptospirosis. There were equivocal findings on the association between IL-1β, TNF-α and IL-10/TNF-α ratio and disease severity.
CONCLUSIONS
Leptospirosis had a wide-range of elevated cytokines. However, prospective studies in-relation to the onset of the symptom are required to better understand the pathophysiology of cytokine response in leptospirosis.
Topics: Adult; Agglutination Tests; Enzyme-Linked Immunosorbent Assay; Female; Humans; India; Interleukin-10; Interleukin-1beta; Leptospirosis; Male; Middle Aged; Severity of Illness Index; Thailand; Tumor Necrosis Factor-alpha
PubMed: 32264832
DOI: 10.1186/s12879-020-04986-9 -
Preventive Veterinary Medicine Dec 2009In the assessment of diagnostic tests the task may arise to show that a candidate test is non-inferior compared to a comparative (standard) test with regard to the... (Comparative Study)
Comparative Study Meta-Analysis
In the assessment of diagnostic tests the task may arise to show that a candidate test is non-inferior compared to a comparative (standard) test with regard to the diagnostic sensitivity or specificity. This setting is known as "one-sided equivalence" and has been applied to a single comparison between two diagnostic tests (Chen et al., 2003). Recently, the approach has been extended into a meta-analytical framework (EFSA, 2006), allowing for the difference between the sensitivity (or specificity) of two diagnostic tests to be estimated using information gathered through systematic literature review. Using this approach, confounding factors are adjusted by matching of parameter estimates on study population and preferred levels of the confounding factors. However, the power of this approach was found to be limited and therefore Markov chain Monte Carlo logistic regression (MCMCLR) models that allow adjustment for confounding variables have been developed (EFSA, 2006). We report here a refinement of the statistical inference based on the latter approach. The objective was to generate a posterior distribution of the meta-analytical difference statistic for the candidate test and a set of comparative tests. The algorithm for this purpose uses Monte Carlo sampling from the posterior distributions of sensitivity (or specificity) and, for each iteration, (i) identifies the least performant comparative test, (ii) establishes the difference statistics for this test and the candidate test and (iii) compares the difference statistic with a critical threshold value. The proportion of iterations in which the critical threshold was exceeded is then interpreted as the P-value for the one-sided equivalence test for the candidate versus the set of comparative tests. We illustrate and discuss the method using a case study on tests for bovine brucellosis.
Topics: Agglutination Tests; Animals; Brucella; Brucellosis, Bovine; Cattle; Complement Fixation Tests; Enzyme-Linked Immunosorbent Assay; Fluorescence Polarization Immunoassay; Immunodiffusion; Logistic Models; Markov Chains; Models, Statistical; Monte Carlo Method; Sensitivity and Specificity
PubMed: 19766334
DOI: 10.1016/j.prevetmed.2009.07.014