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.
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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.