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Humans , Diagnosis , Ethiopia , Health Facilities , Indicators and Reagents , Microscopy , Sensitivity and Specificity , Sputum , TuberculosisABSTRACT
Abstract INTRODUCTION: The molecular test Xpert MTB/RIF (Xpert) has been recommended for use in the diagnosis of pulmonary tuberculosis (PTB); however, data on the cost of incorporating it under routine conditions in high-burden countries are scarce. The clinical impact and costs incurred in adopting the Xpert test in routine PTB diagnosis was evaluated in a prospective study conducted from November 2012 to November of 2013, in the City of Rio de Janeiro, Brazil. METHODS: The diagnostic and therapeutic cascade for TB treatment was evaluated using Xpert in the first stage (S1), and sputum smear microscopy (SSM) in the second stage (S2). The mean costs associated with each diagnostic test were calculated including equipment, human resources, supplies, and infrastructure. RESULTS: We included 232 subjects with probable TB (S1 = 87; S2 = 145). The sensitivities of Xpert and SSM were 91.7% (22/24) and 79.1% (34/43), respectively. The median time between triage and TB treatment initiation in S1 (n = 24) was 14.5 days (IQR 8-28.0) and in S2 (n = 43) it was 8 days [interquartile range (IQR) 6-12.0]. The estimated mean costs per examination in S1 and S2 were US$24.61 and US$6.98, respectively. CONCLUSIONS: Compared with SSM, Xpert test showed a greater sensitivity, but it also had a time delay with respect to treatment initiation and a higher mean cost per examination.
Subject(s)
Humans , Male , Female , Adult , Sputum/microbiology , Tuberculosis, Pulmonary/diagnosis , Mycobacterium tuberculosis/isolation & purification , Predictive Value of Tests , Sensitivity and Specificity , Costs and Cost Analysis , Diagnostic Tests, Routine/economicsABSTRACT
Background: Sputum smear microscopy is the main‑stay in the diagnosis of pulmonary tuberculosis in many developing countries. To overcome the drop outs, same day diagnosis is ideal. Materials and Methods: In the current study, two spot sputum samples (SS2 approach) are collected within a gap of one hour (same day sputum smear microscopy) in addition to the standard spot morning (SM) approach. The smears were stained with standard Ziehl Neelsen (ZN) and modified ZN staining techniques. Results: Out of 1537 patients, sputum smear positivity (SSP) was 9.43% (146 patients) in SM approach with standard ZN staining. Smear positivity was increased to 9.8% (151 patients) with modified ZN staining. For SS2 approach, SSP was 9.37% (144 patients) and 9.8% (151 patients) with standard and modified ZN staining procedures, respectively. Conclusions: Diagnosis of lung tuberculosis is possible with two spot sputum samples with modified ZN staining.
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O Programa Nacional de Controle da Tuberculose (TB) do Ministério da Saúde utiliza a baciloscopia de escarro como metodologia padrão no diagnóstico da TB pulmonar. Para garantir a qualidade do exame é recomendado o uso de Controle Externo de Qualidade (CEQ) da baciloscopia na rede de laboratórios de diagnóstico de TB. Neste estudo foi avaliada a qualidade das baciloscopias de escarro da rede de laboratórios locais, por meio de supervisão indireta, na Região Metropolitana da Baixada Santista/SP. Em nove laboratórios locais foram analisadas 5.691 baciloscopias, coradas pelo Ziehl-Neelsen. Tais amostras foram avaliadas nos seguintes itens: análise macroscópica (distensão) e microscópica (coloração) dos esfregaços e o índice baciloscópico (C%). Para avaliá-las, utilizou-se a metodologia padrão do Manual Nacional de Vigilância Laboratorial de TB e outras Micobactérias/MS de 2008. Utilizando-se metodologia recomendada, das 713 lâminas analisadas, 529 (74,2 %) foram satisfatórias na avaliação macroscópica e 631 (88,5 %), satisfatórias na avaliação microscópica. Na análise da releitura, uma unidade laboratorial apresentou dois resultados falsos positivos e C = 97,5 %. Embora os resultados encontrados tenham sido aceitáveis, sugere-se a realização de atividades contínuas do CEQ, com ênfase na aplicação de ações corretivas nas principais causas de erro no desenvolvimento da técnica de baciloscopia.
The Brazilian Ministry of Health national program for tuberculosis (TB) control (Programa Nacional deControle da Tuberculose) determines the sputum smear microscopy as the standard methodology for TBdiagnosis. In order to achieve diagnosis quality assurance it is recommended to set up an External QualityAssessment (EQA) scheme in the TB diagnosis laboratory network. This study aimed at evaluating thequality of sputum smear microscopy performed by the local laboratory network of the metropolitanarea of Baixada Santista, SP, by means of an indirect supervision. The 5,691 sputum samples stained withZiehl-Neelsen in nine local laboratories were evaluated. The applied EQA methodology was in accordancewith the National TB and Other AFB Laboratory Surveillance Manual Ministry of Health, 2008. Theanalyzed parameters were: macroscopic (smear uniformity) and microscopic (staining) analyses of thesputum smears and bacilloscopic index (C%). Of 713 analyzed slides, 529 (74.2 %) were satisfactory onmacroscopic features and 631 (88.5 %) on microscopic evaluation. In the slides rechecking, one laboratoryshowed two false-positive results and C =97.5 %. Although the general results have been acceptable, acontinuous EQA activity should be carried out, emphasizing the use of correcting actions on the commonsources of error that may occur in performing the AFB microscopy technique.
Subject(s)
Humans , Sputum/microbiology , Laboratories , Tuberculosis, Pulmonary/diagnosis , Brazil , Quality ControlABSTRACT
Background: Sputum smear microscopy is the initial and rapid diagnostic technique for tuberculosis. This requires two (spot and morning SM) sputum sample examinations over two days. Collection of two spot samples (SS2) on the same day would reduce the number of visits, time, money and early initiation of treatment. Methods: We evaluated same day approach (SS2) against standard (SM) for the diagnosis of pulmonary tuberculosis. Results: Out of 658 participants, same day approach could identify 62 cases, whereas standard approach could identify 64 cases. Both the approaches are equally effective (p>0.05). Conclusion: The diagnosis of pulmonary tuberculosis is possible in one day by examining two spot samples.
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Objective: To assess the proficiency of Senior TB Laboratory Supervisors (STLSs) and district level Laboratory Technicians (LTs) in sputum smear microscopy. Method: Intermediate Reference Laboratory (IRL), Ahmedabad had manufactured and validated Proficiency Panel Testing slides from sputum samples, made On Site Evaluation (OSE) visits of District TB Centres (DTCs) in two rounds, and conducted Proficiency Panel Testing of STLSs & DTC-LTs from January 2005 to June 2009. Results: High level of concordance in Z-N smear grading was found between Microbiologist and district laboratory staff. DTC readers reported overall consistency level of more than 98% in Z-N grade agreement during both the IRL, EQA, OSE visits. The tendency to over-grade the panel slides was much higher (more than 22%) as compared to under-grade (less than 2%) them in “correct slides”. High False Positive (HFP) error was not observed in the present study. Conclusion: Laboratory supervisor’s proficiency can be quickly assessed by Proficiency Panel Testing, under multi-level quality assurance network system of sputum smear microscopy in public health programmes like the RNTCP. Proficiency Panel Testing is highly replicable and reproducible tool for quick and reliable assessment of proficiency of the staff and it can be made more effective by raising the proportion of lower grade positive slides in panel set of each reader. DTC readers’ overall agreement level of more than 98% in Z-N grade suggests high level of precision and excellent consistency during both the IRL, EQA, OSE rounds. It is concluded that even for a large network of sputum smear microscopy centres under public health programmes like the RNTCP in order to take corrective action, Proficiency Panel Testing can be effectively used for quick identification of suboptimal- technical performance of the supervisory staff.