RESUMO
Introduction: To reach the goal of malaria elimination in Ecuador for the year 2020, it is necessary to have a laboratory network with the capacity to perform microscopic diagnosis according to the WHO/PAHO quality standards and to provide the adequate treatment of cases. Objective: To determine the level of competence for parasitological diagnosis of the microscopists from the local public network and the performance of intermediate reference laboratories. Materials and methods: We conducted a cross-sectional study based on the information collected in workshops carried out to appraise the competence for microscopic diagnosis of the local laboratory network (zonal health coordinating offices 1 to 8) using a slide panel to evaluate diagnosis agreement, as well as the diagnostic performance of the intermediate laboratories using an external quality assessment program. The results were compared against the reference standards of the supranational laboratory in Perú. Results: We evaluated the competencies of 191 microscopists in 11 workshops and 153 (80.1%) of them were approved. The medians of the indicators were the following: concordance for parasite detection, 100% (Q1- Q3: 96-100), concordance for species identification, 100% (Q1- Q3: 93-100), and concordances for stage identification, 93.0% (Q1- Q3: 86-95) and parasite counting, 77.0% (Q1- Q3: 71-82). In the external quality assessment, the three intermediate laboratories obtained 100% in parasite detection concordance and 96% for species detection concordance. Conclusions: The results for the primary network and the performance indicators for the intermediate laboratories showed the high-quality standards of the training program implemented in the country.
Introducción. El cumplimiento de la meta de eliminación de la malaria en Ecuador en el 2020 exige contar con la capacidad requerida para el diagnóstico microscópico ajustado a los estándares de calidad de la Organización Mundial de la Salud (OMS) y de la Organización Panamericana de la Salud (OPS) y proveer el tratamiento adecuado a los pacientes. Objetivo. Conocer la idoneidad o competencia de los microscopistas de la red pública local para el diagnóstico parasitológico de la malaria y el desempeño de los laboratorios intermedios de referencia. Materiales y métodos. Se hizo un estudio descriptivo de corte transversal a partir de la información obtenida en los talleres de evaluación de idoneidad en el diagnóstico microscópico de la red de laboratorios en las coordinaciones zonales de salud utilizando un panel de láminas para evaluar la concordancia del diagnóstico. Además, se calificó el desempeño de los laboratorios intermedios en el diagnóstico en el marco del programa de evaluación externa del desempeño. Los resultados se compararon con los obtenidos por el laboratorio supranacional de Perú. Resultados. En los 11 talleres realizados, se evaluó la idoneidad de 191 microscopistas, de los cuales 153 (80,1 %) aprobaron las pruebas. Las medianas de los indicadores fueron las siguientes: concordancia entre la detección y el resultado, 100 % (Q1- Q3: 96-100); concordancia en la especie, 100 % (Q1- Q3: 93-100); concordancia en el estadio, 93,0 % (Q1- Q3: 86-95) y concordancia en el recuento, 77 % (Q1- Q3: 71-82). En el programa de evaluación externa de desempeño, los tres laboratorios intermedios obtuvieron una concordancia del 100 % en el resultado y una del 96 % en la especie. Conclusiones. Los indicadores de competencia de la red local y de desempeño de los laboratorios intermedios alcanzaron altos estándares de calidad acordes con el proceso de entrenamiento implementado en el país.
Assuntos
Eritrócitos/parasitologia , Ensaio de Proficiência Laboratorial , Malária Falciparum/diagnóstico , Malária Vivax/diagnóstico , Pessoal de Laboratório Médico/estatística & dados numéricos , Microscopia/métodos , Parasitemia/diagnóstico , Plasmodium falciparum/isolamento & purificação , Plasmodium vivax/isolamento & purificação , Estudos Transversais , Equador , Eritrócitos/ultraestrutura , Feminino , Humanos , Laboratórios/classificação , Laboratórios/normas , Malária Falciparum/sangue , Malária Falciparum/prevenção & controle , Malária Vivax/sangue , Malária Vivax/prevenção & controle , Masculino , Pessoal de Laboratório Médico/educação , Microscopia/normas , Parasitemia/sangue , Parasitemia/prevenção & controle , Prática Profissional/estatística & dados numéricos , Garantia da Qualidade dos Cuidados de Saúde , Fatores SocioeconômicosRESUMO
Resumen Introducción. El cumplimiento de la meta de eliminación de la malaria en Ecuador en el 2020 exige contar con la capacidad requerida para el diagnóstico microscópico ajustado a los estándares de calidad de la Organización Mundial de la Salud (OMS) y de la Organización Panamericana de la Salud (OPS) y proveer el tratamiento adecuado a los pacientes. Objetivo. Conocer la idoneidad o competencia de los microscopistas de la red pública local para el diagnóstico parasitológico de la malaria y el desempeño de los laboratorios intermedios de referencia. Materiales y métodos. Se hizo un estudio descriptivo de corte transversal a partir de la información obtenida en los talleres de evaluación de idoneidad en el diagnóstico microscópico de la red de laboratorios en las coordinaciones zonales de salud utilizando un panel de láminas para evaluar la concordancia del diagnóstico. Además, se calificó el desempeño de los laboratorios intermedios en el diagnóstico en el marco del programa de evaluación externa del desempeño. Los resultados se compararon con los obtenidos por el laboratorio supranacional de Perú. Resultados. En los 11 talleres realizados, se evaluó la idoneidad de 191 microscopistas, de los cuales 153 (80,1 %) aprobaron las pruebas. Las medianas de los indicadores fueron las siguientes: concordancia entre la detección y el resultado, 100 % (Q1- Q3: 96-100); concordancia en la especie, 100 % (Q1- Q3: 93-100); concordancia en el estadio, 93,0 % (Q1- Q3: 86-95) y concordancia en el recuento, 77 % (Q1- Q3: 71-82). En el programa de evaluación externa de desempeño, los tres laboratorios intermedios obtuvieron una concordancia del 100 % en el resultado y una del 96 % en la especie. Conclusiones. Los indicadores de competencia de la red local y de desempeño de los laboratorios intermedios alcanzaron altos estándares de calidad acordes con el proceso de entrenamiento implementado en el país.
Abstract Introduction: To reach the goal of malaria elimination in Ecuador for the year 2020, it is necessary to have a laboratory network with the capacity to perform microscopic diagnosis according to the WHO/PAHO quality standards and to provide the adequate treatment of cases. Objective: To determine the level of competence for parasitological diagnosis of the microscopists from the local public network and the performance of intermediate reference laboratories. Materials and methods: We conducted a cross-sectional study based on the information collected in workshops carried out to appraise the competence for microscopic diagnosis of the local laboratory network (zonal health coordinating offices 1 to 8) using a slide panel to evaluate diagnosis agreement, as well as the diagnostic performance of the intermediate laboratories using an external quality assessment program. The results were compared against the reference standards of the supranational laboratory in Perú. Results: We evaluated the competencies of 191 microscopists in 11 workshops and 153 (80.1%) of them were approved. The medians of the indicators were the following: concordance for parasite detection, 100% (Q1- Q3: 96-100), concordance for species identification, 100% (Q1- Q3: 93-100), and concordances for stage identification, 93.0% (Q1- Q3: 86-95) and parasite counting, 77.0% (Q1- Q3: 71-82). In the external quality assessment, the three intermediate laboratories obtained 100% in parasite detection concordance and 96% for species detection concordance. Conclusions: The results for the primary network and the performance indicators for the intermediate laboratories showed the high-quality standards of the training program implemented in the country.
Assuntos
Feminino , Humanos , Masculino , Plasmodium falciparum/isolamento & purificação , Plasmodium vivax/isolamento & purificação , Malária Vivax/diagnóstico , Malária Falciparum/diagnóstico , Pessoal de Laboratório Médico/estatística & dados numéricos , Parasitemia/diagnóstico , Eritrócitos/parasitologia , Ensaio de Proficiência Laboratorial , Microscopia/métodos , Prática Profissional/estatística & dados numéricos , Garantia da Qualidade dos Cuidados de Saúde , Fatores Socioeconômicos , Estudos Transversais , Malária Vivax/sangue , Malária Vivax/prevenção & controle , Malária Falciparum/sangue , Malária Falciparum/prevenção & controle , Pessoal de Laboratório Médico/educação , Parasitemia/sangue , Parasitemia/prevenção & controle , Equador , Eritrócitos/ultraestrutura , Laboratórios/classificação , Laboratórios/normas , Microscopia/normasRESUMO
OBJECTIVES: Trichomonas vaginalis (TV) infection is the most common non-viral STI globally and can result in adverse pregnancy outcomes and exacerbated HIV acquisition/transmission. Nucleic acid amplification tests (NAATs) are the most sensitive diagnostic tests, with high specificity, but TV NAATs are rarely used in Brazil. We investigated the TV prevalence and compared the performance of the US Food and Drug Association-cleared Aptima TV assay with microscopy (wet mount and Gram-stained) and culture for TV detection in women in Pelotas, Brazil in an observational study. METHODS: From August 2015 to December 2016, 499 consecutive asymptomatic and symptomatic sexually active women attending a Gynaecology and Obstetrics Outpatient Clinic were enrolled. Vaginal fluid and swab specimens were collected and wet mount microscopy, Gram-stained microscopy, culture and the Aptima TV assay performed. RESULTS: The median age of enrolled women was 36.5 years (range: 15-77). The majority were white, had a steady sexual partner and low levels of education. The TV detection rate was 4.2%, 2.4%, 1.2% and 0% using the Aptima TV assay, culture, wet mount microscopy and Gram-stained microscopy, respectively. The sensitivity of culture and wet mount microscopy was only 57.1% (95% CI 36.5 to 75.5) and 28.6% (95% CI 13.8 to 50.0), respectively. CONCLUSIONS: A 4.2% positivity rate of T. vaginalis was found among women in Pelotas, Brazil and the routine diagnostic test (wet mount microscopy) and culture had low sensitivities. More sensitive diagnostic tests (NAATs) and enhanced testing of symptomatic and asymptomatic at-risk women are crucial to mitigate the transmission of TV infection, TV-associated sequelae and enhanced HIV acquisition and transmission.
Assuntos
Microscopia/normas , Kit de Reagentes para Diagnóstico/normas , Tricomoníase/diagnóstico , Vaginite por Trichomonas/diagnóstico , Trichomonas vaginalis/isolamento & purificação , Adolescente , Adulto , Idoso , Brasil/epidemiologia , Ensaio de Unidades Formadoras de Colônias/métodos , Ensaio de Unidades Formadoras de Colônias/normas , Erros de Diagnóstico , Feminino , Violeta Genciana , Humanos , Microscopia/métodos , Pessoa de Meia-Idade , Fenazinas , Prevalência , Sensibilidade e Especificidade , Tricomoníase/epidemiologia , Vaginite por Trichomonas/epidemiologia , Estados Unidos , United States Food and Drug Administration , Adulto JovemRESUMO
Cutaneous leishmaniasis is endemic to South America where diagnosis is most commonly conducted via microscopy. Patients with suspected leishmaniasis were referred for enrollment by the Ministry of Health (MoH) in Lima, Iquitos, Puerto Maldonado, and several rural areas of Peru. A 43-question survey requesting age, gender, occupation, characterization of the lesion(s), history of leishmaniasis, and insect-deterrent behaviors was administered. Polymerase chain reaction (PCR) was conducted on lesion materials at the Naval Medical Research Unit No. 6 in Lima, and the results were compared with those obtained by the MoH using microscopy. Factors associated with negative microscopy and positive PCR results were identified using χ2 test, t-test, and multivariate logistic regression analyses. Negative microscopy with positive PCR occurred in 31% (123/403) of the 403 cases. After adjusting for confounders, binary multivariate logistic regression analyses revealed that negative microscopy with positive PCR was associated with patients who were male (adjusted odds ration [OR] = 1.93 [1.06-3.53], P = 0.032), had previous leishmaniasis (adjusted OR = 2.93 [1.65-5.22], P < 0.0001), had larger lesions (adjusted OR = 1.02 [1.003-1.03], P = 0.016), and/or had a longer duration between lesion appearance and PCR testing (adjusted OR = 1.12 [1.02-1.22], P = 0.017). Future research should focus on further exploration of these underlying variables, discovery of other factors that may be associated with negative microscopy diagnosis, and the development and implementation of improved testing in endemic regions.
Assuntos
Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/epidemiologia , Microscopia/normas , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Estudos Transversais , DNA de Protozoário/genética , Feminino , Humanos , Lactente , Recém-Nascido , Leishmania/genética , Leishmania/isolamento & purificação , Masculino , Microscopia/métodos , Pessoa de Meia-Idade , Peru/epidemiologia , Reação em Cadeia da Polimerase , Prevalência , Vigilância de Evento Sentinela , Inquéritos e Questionários , Adulto JovemRESUMO
BACKGROUND: Baciloscopy is the primary tool for pulmonary tuberculosis diagnosis, being this technique the most used internationally in the search for infectious cases. Quality control is the process of the rechecking smears by a highly qualified observer. AIM: To evaluate and highlight the importance of quality control of smear microscopy in the Provincial Laboratories diagnosticians of Tuberculosis in Cuba. METHODS: This study was conducted at the National Reference Laboratory and Research in Tuberculosis, Leprosy and Mycobacteria in the Institute of Tropical Medicine "Pedro Kouri", Havana, Cuba, Were evaluated 2676 smears received from January 2013 to December 2014, from Provincial Centers of Hygiene, Epidemiology and Microbiology of Cuba, including the special municipality Isla de la Juventud. RESULTS: 2,664 (99.5%) were concordant smears, the correlation obtained for the positive smears were 96.5% and 99.8% for negative. Were identified12 reading errors: 7 (3.5%) false positive and 5 (0.2%) false negatives. Slides were classified with adequate quality of smears in 2039 (76.2%), showed difficulties in realizing the extension in 1464 (54.7%) and staining were adequate in 2343 (87.6%). The kappa index was 0.9674. CONCLUSION: Although there was good agreement between observations it is recommended to improve the quality of extended, maintain staff training program that performs this activity, like regular supervision by specialists, to further improve the quality of diagnosis.
Assuntos
Microscopia/normas , Mycobacterium tuberculosis , Controle de Qualidade , Escarro/microbiologia , Tuberculose/diagnóstico , Cuba , Erros de Diagnóstico , Humanos , Valor Preditivo dos Testes , Padrões de Referência , Coloração e Rotulagem/métodosRESUMO
Introducción: La baciloscopia es la herramienta primaria en el diagnóstico de la tuberculosis (TBC) pulmonar activa, siendo esta la técnica más utilizada internacionalmente en la búsqueda de casos infecciosos. El control de calidad consiste en la relectura de las láminas por un observador altamente calificado. Objetivo: Evaluar y destacar la importancia del control de la calidad de la baciloscopia en los laboratorios provinciales encargados del diagnóstico de TBC en Cuba. Material y Métodos: Este estudio fue realizado en el Laboratorio Nacional de Referencia e Investigaciones de Tuberculosis, Lepra y Micobacterias del Instituto de Medicina Tropical "Pedro Kourí", La Habana, Cuba. Fueron evaluadas 2.676 láminas recibidas en el período de enero de 2013-diciembre de 2014, procedentes de los diferentes Centros Provinciales de Higiene, Epidemiología y Microbiología de Cuba, incluido el Municipio Especial Isla de la Juventud. Resultados: Hubo 2.664 (99,5%) láminas concordantes, la concordancia obtenida para las láminas positivas fue 96,5% y las negativas 99,8%. Se identificaron 12 errores de lectura: 7 (3,5%) falsos positivos, 5 (0,2%) falsos negativos. Se calificaron láminas con calidad de la muestra adecuada en 2.039 (76,2%), presentaron deficiencias en la realización de la extensión 1.464 (54,7%), y la tinción fue adecuada en 2.343 (87,6%). El índice de kappa fue de 0.9674. Conclusión: Aunque hubo una adecuada concordancia entre las observaciones realizadas, se recomienda mejorar la calidad del extendido, mantener programa de entrenamiento al personal que realiza esta actividad, al igual que las supervisiones periódicas por parte de especialistas, para continuar mejorando la calidad del diagnóstico.
Background: Baciloscopy is the primary tool for pulmonary tuberculosis diagnosis, being this technique the most used internationally in the search for infectious cases. Quality control is the process of the rechecking smears by a highly qualified observer. Aim: To evaluate and highlight the importance of quality control of smear microscopy in the Provincial Laboratories diagnosticians of Tuberculosis in Cuba. Methods: This study was conducted at the National Reference Laboratory and Research in Tuberculosis, Leprosy and Mycobacteria in the Institute of Tropical Medicine "Pedro Kouri", Havana, Cuba, Were evaluated 2676 smears received from January 2013 to December 2014, from Provincial Centers of Hygiene, Epidemiology and Microbiology of Cuba, including the special municipality Isla de la Juventud. Results: 2,664 (99.5%) were concordant smears, the correlation obtained for the positive smears were 96.5% and 99.8% for negative. Were identified12 reading errors: 7 (3.5%) false positive and 5 (0.2%) false negatives. Slides were classified with adequate quality of smears in 2039 (76.2%), showed difficulties in realizing the extension in 1464 (54.7%) and staining were adequate in 2343 (87.6%). The kappa index was 0.9674. Conclusion: Although there was good agreement between observations it is recommended to improve the quality of extended, maintain staff training program that performs this activity, like regular supervision by specialists, to further improve the quality of diagnosis.
Assuntos
Humanos , Controle de Qualidade , Escarro/microbiologia , Tuberculose/diagnóstico , Microscopia/normas , Mycobacterium tuberculosis , Padrões de Referência , Coloração e Rotulagem/métodos , Valor Preditivo dos Testes , Cuba , Erros de DiagnósticoRESUMO
Semen analysis is the first step in the evaluation of an infertile couple. Within this process, an accurate and objective morphological analysis becomes more critical as it is based on the correct detection and segmentation of human sperm components. In this paper, we present an improved two-stage framework for detection and segmentation of human sperm head characteristics (including acrosome and nucleus) that uses three different color spaces. The first stage detects regions of interest that define sperm heads, using k-means, then candidate heads are refined using mathematical morphology. In the second stage, we work on each region of interest to segment accurately the sperm head as well as nucleus and acrosome, using clustering and histogram statistical analysis techniques. Our proposal is also characterized by being fully automatic, where a user intervention is not required. Our experimental evaluation shows that our proposed method outperforms the state-of-the-art. This is supported by the results of different evaluation metrics. In addition, we propose a gold-standard built with the cooperation of a referent expert in the field, aiming to compare methods for detecting and segmenting sperm cells. Our results achieve notable improvement getting above 98% in the sperm head detection process at the expense of having significantly fewer false positives obtained by the state-of-the-art method. Our results also show an accurate head, acrosome and nucleus segmentation achieving over 80% overlapping against hand-segmented gold-standard. Our method achieves higher Dice coefficient, lower Hausdorff distance and less dispersion with respect to the results achieved by the state-of-the-art method.
Assuntos
Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/normas , Microscopia/métodos , Microscopia/normas , Reconhecimento Automatizado de Padrão/normas , Análise do Sêmen/normas , Cabeça do Espermatozoide/ultraestrutura , Inteligência Artificial , Células Cultivadas , Chile , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Reconhecimento Automatizado de Padrão/métodos , Padrões de Referência , Reprodutibilidade dos Testes , Análise do Sêmen/métodos , Sensibilidade e EspecificidadeRESUMO
Trypanosoma evansi is a flagellated protozoan that parasitizes a wide variety of mammals, occasionally including humans. In South America, it infects horses, cattle, buffaloes, dogs and wild mammals, causing a disease known as "Mal de Caderas", which results in important economic losses due to a wide range of pathological expressions. Argentina represents the southern limit of its distribution. The capybara (Hydrochoerus hydrochaeris) is a large rodent found in tropical to temperate freshwater wetlands of South America. As capybaras infected with T. evansi present no clinical signs of disease, withstanding high parasitaemia, this species was proposed as a reservoir host. In this study we investigated the prevalence and parasitaemic intensity of T. evansi in samples obtained from 60 free-ranging capybaras of Esteros del Iberá (Corrientes province, northeastern Argentina) using smear microscopy and real-time PCR assays. All the cases of capybaras infected with T. evansi were found during one of the years studied, with no evidence of seasonality. The overall infection prevalence was 10%, but between years it ranged from 0% to 17% (in 2011). This is the first confirmation of T. evansi infection in Argentina by molecular biology techniques. Our results showed no differences between the methods used to detect the presence of T. evansi in capybaras, which indicates that simple methods like microscopy can generate important data on the ecoepidemiology of this parasite. Both techniques used in this study represent a viable tool for ecoepidemiological studies, and can be used to produce good estimates of prevalence and parasitaemic level of the infection, which inform for the implementation of strategies for the control of the disease.
Assuntos
Animais Selvagens/parasitologia , Microscopia/veterinária , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Doenças dos Roedores/epidemiologia , Roedores/parasitologia , Tripanossomíase/veterinária , Animais , Argentina/epidemiologia , Métodos Epidemiológicos/veterinária , Microscopia/normas , Carga Parasitária , Prevalência , Reação em Cadeia da Polimerase em Tempo Real/normas , Trypanosoma/genética , Tripanossomíase/epidemiologiaRESUMO
The quality of routine malaria diagnosis is a crucial topic of malaria control. The aim of this assessment was to monitor and evaluate the quality of routine malaria diagnosis in Amazonas (Venezuela) and to improve the quality control system. The traditional non-blinded quality control system was found to be overburdened with diagnostic samples. A modified sampling system with fewer samples to be tested was proposed. Expert microscopists blindly double-checked 1000 slides and 550 rapid diagnostic tests (RDT) (OptiMAL-IT) from health posts (HP). For Plasmodium vivax, HP microscopy and OptiMAL-IT showed sensitivies of 86% and 63%, respectively. For P. falciparum, HP microscopy and OptiMAL-IT showed sensitivities of 68% and 89%, respectively. Both methods lost accuracy when fewer parasites occurred in the sample. HP microscopists from different municipalities displayed significant differences in diagnostic quality. Overall, quality of routine malaria diagnosis in the Venezuelan Amazon is good but not optimal. The change from the traditional non-blinded quality control system to blinded cross-checking of a minimal selection of samples is - comparatively - a low cost intervention with possibly high impact on the quality of routine malaria diagnosis. The introduction of RDTs should be discussed carefully in order not to displace an existing network of HP microscopists.
Assuntos
Malária/diagnóstico , Microscopia/normas , Plasmodium falciparum/isolamento & purificação , Plasmodium vivax/isolamento & purificação , Kit de Reagentes para Diagnóstico/normas , Animais , Método Duplo-Cego , Humanos , Malária/epidemiologia , Microscopia/métodos , Controle de Qualidade , Sensibilidade e Especificidade , Venezuela/epidemiologiaRESUMO
SETTING: Ten peripheral laboratories performing routine acid-fast bacilli (AFB) smear microscopy in Lima, Peru. OBJECTIVES: To test whether external quality assessment (EQA) rechecking of AFB smears becomes more efficient with stratified lot sampling of treatment follow-up smears. DESIGN: In 2 consecutive years, a stratified lot sample of 36 treatment follow-up slides and 24 diagnostic slides were randomly selected and blindly rechecked. A second controller determined the final result for discordant slides. Feedback was provided to laboratory technicians during supervisory visits. RESULTS: More false-negative errors were found in the follow-up slides than in the tuberculosis suspect slides: 25 vs. 3. This represented a yield of 3.5% in 720 follow-up slides and only 0.6% in 480 diagnostic slides. Positive predictive values were high in both years. Respectively three and eight laboratories did not reach a relative sensitivity of >65% during the first and second year, and a clear improvement was seen in only one laboratory. Excessive workload seemed to preclude raising the level of routine performance. CONCLUSIONS: EQA with stratified lot sampling of treatment follow-up slides proved very efficient and effective for identifying laboratories with substandard performance in a setting with low positivity rates in routine diagnostic smears.
Assuntos
Técnicas de Laboratório Clínico/normas , Microscopia/normas , Mycobacterium tuberculosis/isolamento & purificação , Indicadores de Qualidade em Assistência à Saúde , Tuberculose/diagnóstico , Antituberculosos/uso terapêutico , Reações Falso-Negativas , Reações Falso-Positivas , Humanos , Variações Dependentes do Observador , Peru , Guias de Prática Clínica como Assunto , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Resultado do Tratamento , Tuberculose/tratamento farmacológico , Tuberculose/microbiologia , Carga de TrabalhoRESUMO
Manual reticulocyte counts were examined under light microscopy, using the property whereby supravital stain precipitates residual ribosomal RNA versus the automated flow methods, with the suggestion that in the latter there is greater precision and an ability to determine both mature and immature reticulocyte fractions. Three hundred and forty-one venous blood samples of patients were analyzed of whom 224 newborn and the rest adults; 51 males and 66 females, with ages between 0 and 89 years, as part of the laboratory routine for hematological examinations at the Clinical Laboratory of the Hospital Universitário do Oeste do Paraná. This work aimed to compare manual and automated methodologies for reticulocyte countings and evaluate random and systematic errors. The results obtained showed that the difference between the two methods was very small, with an estimated 0·4% systematic error and 3·9% random error. Thus, it has been confirmed that both methods, when well conducted, can reflect precisely the reticulocyte counts for adequate clinical use.
Assuntos
Citometria de Fluxo/métodos , Microscopia/métodos , Contagem de Reticulócitos/métodos , Contagem de Reticulócitos/normas , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Automação , Criança , Pré-Escolar , Feminino , Citometria de Fluxo/normas , Humanos , Lactente , Recém-Nascido , Masculino , Microscopia/normas , Pessoa de Meia-Idade , RNA Ribossômico , Reprodutibilidade dos Testes , Contagem de Reticulócitos/instrumentação , Adulto JovemRESUMO
Objetivos. Evaluar la competencia de los microscopistas en el diagnóstico de la malaria mediante paneles de láminas estandarizados en la Amazonía peruana. Materiales y métodos. Estudio transversal, realizado entre los meses de julio y septiembre de 2007, en 122 establecimientos de salud de primer nivel de atención de la Amazonía peruana. En el marco del Proyecto PAMAFRO, se evaluó las competencias en el diagnóstico de malaria en 68 microscopistas sin experiencia (
Objectives. To assess the competency of microscopists for malaria diagnosis using standardized slide sets in the Peruvian Amazon. Material and methods. Cross-sectional study carried out in 122 first level health facilities of the Peruvian Amazon, between July and September 2007. Within the frame of the project "Control Malaria in the border areas of the Andean Region: A community approach" (PAMAFRO), we evaluated the malaria diagnosis performance in 68 microscopists without expertise (< 1 year of expertise) and 76 microscopists with expertise (> 1 year) using standardized sets of 20 blood smear slides according to the World Health Organization (WHO) recommendations. A correct diagnosis (correct species identification) was defined as "agreement", a microscopist was qualified as an "expert" if they have an agreement ≥90 percent (≥ 18 slides with correct diagnosis), as a "referent" with an agreement between 80 percent and <90 percent, "competent" if they are between 70 and <80 percent and "in training" if they have <70 percent. Results. Microscopists with expertise (68.6 percent) had more agreement than those without expertise (48.2 percent). The competency assessment was acceptable (competent, referent, or experts levels) in 11.8 percent of the microscopists without expertise and in 52.6 percent from those with expertise. The agreement was lower using blood smear slides with P. falciparum with low parasitaemia, with P. malariae and with mixed infections. Conclusions. Is the first assessment, we found only one of three microscopists from the Peruvian Amazon is competent fro malaria diagnosis according to the WHO standards. From this baseline data, we have to continue working in order to improve the competency assessment of the microscopists within the frame of a quality assurance system.
Assuntos
Humanos , Malária/sangue , Malária/diagnóstico , Competência Profissional/normas , Técnicas de Laboratório Clínico , Estudos Transversais , Microscopia/normas , Parasitologia/normas , PeruRESUMO
OBJECTIVES: To assess the competency of microscopists for malaria diagnosis using standardized slide sets in the Peruvian Amazon. MATERIAL AND METHODS: Cross-sectional study carried out in 122 first level health facilities of the Peruvian Amazon, between July and September 2007. Within the frame of the project "Control Malaria in the border areas of the Andean Region: A community approach" (PAMAFRO), we evaluated the malaria diagnosis performance in 68 microscopists without expertise (< 1 year of expertise) and 76 microscopists with expertise (> 1 year) using standardized sets of 20 blood smear slides according to the World Health Organization (WHO) recommendations. A correct diagnosis (correct species identification) was defined as "agreement", a microscopist was qualified as an "expert" if they have an agreement ≥90% (≥ 18 slides with correct diagnosis), as a "referent" with an agreement between 80% and <90%, "competent" if they are between 70 and <80% and "in training" if they have <70%. RESULTS: Microscopists with expertise (68.6%) had more agreement than those without expertise (48.2%). The competency assessment was acceptable (competent, referent, or experts levels) in 11.8% of the microscopists without expertise and in 52.6% from those with expertise. The agreement was lower using blood smear slides with P. falciparum with low parasitaemia, with P. malariae and with mixed infections. CONCLUSIONS: Is the first assessment, we found only one of three microscopists from the Peruvian Amazon is competent fro malaria diagnosis according to the WHO standards. From this baseline data, we have to continue working in order to improve the competency assessment of the microscopists within the frame of a quality assurance system.
Assuntos
Malária/sangue , Malária/diagnóstico , Competência Profissional/normas , Técnicas de Laboratório Clínico/normas , Estudos Transversais , Humanos , Microscopia/normas , Parasitologia/normas , PeruRESUMO
To improve practical, accurate diagnosis of malaria in the Amazon rainforest of Venezuela, two rapid diagnostic tests (RDT) (OptiMAL-IT) and FalciVax) and a laboratory light microscope, used in the field with a battery-operated head lamp as an external light source, were evaluated against the standard laboratory microscope procedure for malaria detection. One hundred and thirty-six Yanomami patients were studied for the presence of malaria parasites. Thirty-three patients (24%) were positive for malaria (Plasmodium falciparum, P. vivax, P. malariae). Twenty-one (64%) of the positive patients had <100 parasites/microl. Both RDTs showed poor sensitivity (24.2% for OptiMAL-IT) and 36.4% for FalciVax) but good specificity (99% both for OptiMAL-IT) and FalciVax). Field and laboratory microscopy showed sensitivities of 94% and 91%, respectively. The kappa coefficient was 0.90, indicating a high agreement between field and laboratory microscopy. We conclude that (i) adequate slide reading cannot be substituted by either of the two RDTs in the Venezuelan Amazon and (ii) the use of a light source such as that described above makes slide reading more feasible than hitherto in remote areas without electricity.
Assuntos
Malária/diagnóstico , Parasitemia/diagnóstico , Plasmodium/isolamento & purificação , Kit de Reagentes para Diagnóstico/normas , Animais , Humanos , Microscopia/métodos , Microscopia/normas , Controle de Qualidade , Kit de Reagentes para Diagnóstico/parasitologia , Sensibilidade e Especificidade , Venezuela/epidemiologiaRESUMO
SETTING: Sixteen primary care health centres in Peru and Bolivia. OBJECTIVES: To assess the utilisation of microscopy services in Peru and Bolivia and determine if clinical audit, a quality improvement tool, improves the utilisation of these services. DESIGN: We estimated the percentage of patients with suspected tuberculosis (TB) in whom sputum microscopy was effectively utilised in Peru and Bolivia over two 6-month periods before and after a clinical audit intervention that included standards setting, measuring clinical performance and feedback. RESULTS: Before the intervention, only 31% (95%CI 27-35) of TB suspects were assessed with sputum microscopy in Peru. In Bolivia, 30% (95%CI 25-35) underwent at least two sputum microscopy examinations. After clinical audit, the availability of sputum microscopy results improved by respectively 7% (95%CI 1-12, P < 0.05) and 23% (95%CI 15-30, P < 0.05) over 2 years in Peru and Bolivia. CONCLUSIONS: Despite World Health Organization recommendations that all TB suspects should undergo sputum microscopy before treatment, results are available for further assessment for only one third. This is a potentially serious obstacle to TB case detection. Clinical audit can bring some improvement. We recommend regular monitoring of effective utilisation of microscopy services and investigations to ascertain organisational and structural issues in their uptake and use.
Assuntos
Acessibilidade aos Serviços de Saúde , Necessidades e Demandas de Serviços de Saúde , Programas de Rastreamento/métodos , Auditoria Médica , Microscopia/estatística & dados numéricos , Mycobacterium tuberculosis/isolamento & purificação , Escarro/microbiologia , Tuberculose/diagnóstico , Bolívia/epidemiologia , Fidelidade a Diretrizes , Humanos , Incidência , Microscopia/normas , Peru/epidemiologia , Guias de Prática Clínica como Assunto , Garantia da Qualidade dos Cuidados de Saúde , Tuberculose/epidemiologia , Tuberculose/microbiologiaAssuntos
Laboratórios Hospitalares/normas , Ensaio de Proficiência Laboratorial/métodos , Microscopia/normas , Mycobacterium tuberculosis/isolamento & purificação , Escarro/microbiologia , Tuberculose Pulmonar/microbiologia , Cuba , Reações Falso-Negativas , Reações Falso-Positivas , Hospitais Públicos , Hospitais Urbanos , Humanos , Microscopia/métodos , Mycobacterium tuberculosis/ultraestrutura , Método Simples-Cego , Manejo de Espécimes/métodos , Manejo de Espécimes/normas , Tuberculose Pulmonar/diagnósticoRESUMO
This study was aimed at evaluating the diag-nosis of tuberculosis in Provincial Hygiene and Epidemiological Centers of the country including special municipality Isle of Youth. The quality control was performed on 4 382 sputum smears from January to December 2004 following the Manual of procedures of the National Tuberculosis Control program. Good quality in Ziehl Neelsen extension and staining was seen in 4003 smears (91.35%). The overall agreement coefficient between the National Tuberculosis Reference Laboratory and the rest of the provincial laboratories was 99.79%. Sensitivity and specificity figures were over 99%. These results showed the quality of sputum smears microscopy diagnosis at provincial laboratories and the need of carrying out permanent supervision, monitoring and re-training of staff in acid-fast bacilli test in order to lay down the foundations for the introduction of blind rechecking methods and panel of sputum smears, aimed at improving the tuberculosis diagnosis quality in Cuba.
Assuntos
Ensaio de Proficiência Laboratorial , Microscopia/normas , Mycobacterium tuberculosis/isolamento & purificação , Escarro/microbiologia , Tuberculose/diagnóstico , Álcoois , Corantes , Cuba/epidemiologia , Dermatite de Contato , Reações Falso-Negativas , Reações Falso-Positivas , Humanos , Laboratórios Hospitalares/normas , Laboratórios Hospitalares/estatística & dados numéricos , Azul de Metileno , Microscopia/métodos , Corantes de Rosanilina , Coloração e Rotulagem/métodos , Coloração e Rotulagem/normas , Tuberculose/epidemiologia , Tuberculose/microbiologiaRESUMO
CONTEXTO E OBJETIVO: A giardíase é comum no Brasil. Para o diagnóstico laboratorial, o método mais empregado é o exame microscópico de amostras fecais. O método imunoenzimático (ELISA) também é utilizado. O objetivo deste trabalho é verificar as vantagens e desvantagens do método microscópico quando comparado ao imunoenzimático para o diagnóstico de Giardia lamblia em uma única amostra fecal. TIPO DE ESTUDO E LOCAL: Estudo prospectivo, duplo cego, no Laboratório de Parasitologia, Faculdade de Medicina da Fundação ABC. MÉTODOS: As amostras foram preparadas para exame de acordo com os tradicionais métodos de sedimentação (Hoffman, Pons e Janer) e Faust. Um resultado positivo significa o encontro de Giardia lamblia por um dos métodos ou ambos. O kit Prospect ELISA foi utilizado para detecção do antígeno específico de Giardia lamblia, de acordo com as instruções do fabricante. Os resultados foram expressos em escala visual como negativos ou positivos (+, ++, +++ ou ++++). RESULTADOS: O teste ELISA é positivo mesmo quando uma significante proporção das correspondentes amostras examinadas por microscopia ainda é negativa, sendo esta tendência estatisticamente significante (p < 0,001). A concordância de resultados entre os dois métodos é apenas moderada (0,5 pelo teste kappa). CONCLUSÃO: O teste ELISA é recomendável quando se busca uma elevada sensibilidade para a detecção de antígenos específicos de Giardia lamblia, como em estudos de prevalência. Para a prática diária, recomendamos o método microscópico, que tem custo muito menor e pode detectar outros parasitas na mesma amostra. A baixa taxa de positividade do método no exame de uma única amostra pode ser contornada pelo exame de três amostras, como recomendado pela maioria dos autores.
Assuntos
Humanos , Animais , Antígenos de Protozoários/análise , Ensaio de Imunoadsorção Enzimática/normas , Fezes/parasitologia , Giardia lamblia/isolamento & purificação , Giardíase/diagnóstico , Microscopia/normas , Distribuição de Qui-Quadrado , Custos e Análise de Custo , Método Duplo-Cego , Ensaio de Imunoadsorção Enzimática/economia , Giardia lamblia/imunologia , Giardíase/parasitologia , Microscopia/economia , Estudos ProspectivosRESUMO
SETTING: Laboratories in Mexico that support the national tuberculosis (TB) control program have been involved in an acid-fast bacilli (AFB) microscopy external quality assurance program which includes rechecking 100% of smears identified as AFB-positive by the local laboratories and 10% of smears identified as AFB-negative. Very few errors have been detected in Mexico using non-random selection and unblinded rechecking of the slides. OBJECTIVE: To evaluate the results from a 1-year pilot program involving blinded rechecking of randomly selected AFB slides from local TB laboratories in two Mexican states and determine its feasibility for future implementation. DESIGN: To reduce potential bias, laboratory staff from the National TB Laboratory, Institute for Epidemiological Diagnosis and Reference (InDRE), performed quarterly statistical sampling of AFB smears and on-site evaluations in local laboratories in each state. AFB smears were rechecked at the respective state laboratories with discordant results resolved at InDRE. RESULTS: A significantly greater percentage of errors was detected on the randomly selected, blinded AFB smears than on the non-randomly selected, unblinded smears. CONCLUSION: Random blinded rechecking provides more accurate estimates of AFB microscopy results, resulting in improved diagnosis and monitoring of treatment response.