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@#Abstract: Objective To establish a rapid detection assay based on fluorescence recombinase polymerase amplification (RPA) targeting Necator americanus eggs, and to evaluate its efficacy, providing technical support for rapid detection of Necator americanus in fecal samples. Methods The fluorescence RPA primers and probe were designed based on the cox1 gene of Necator americanus and then screened the optimal combination to develop the assay. The genomic DNA of Necator americanus eggs was diluted to 7 concentration gradients including 100 pg/µL, 10 pg/µL, 1 pg/µL, 100 fg/µL, 10 fg/µL, 1 fg/µL, 0.1 fg/µL, to determine the detection limit of the assay. The specificity of the assay was demonstrated by detected genomic DNA from Schistosoma japonicum, Ascaris lumbricoides, Clonorchis sinensis and Fasciola hepatica. A total of 44 fecal samples were collected and DNA extraction was performed, and the modified Kato-Katz method, semi-nest PCR method, and fluorescent RPA method were simultaneously used for detection to evaluate the sensitivity and specificity. Results The established fluorescence RPA assay can specifically amplify a fragment of 194 bp of the Necator americanus cox1 gene within 20 min, with a detection limit of 10 fg/µL. There was no cross-reactivity with Schistosoma japonicum, Ascaris lumbricoides, Clonorchis sinensis, Fasciola hepatica after specificity validation. In 44 fecal samples, 27 positive samples were detected by the fluorescence RPA assay, and 26 positive samples were detected by both the Kato-Katz and the semi-nested PCR. The fluorescence curve of sample number 1 was slightly higher than the negative control in the later stage of the reaction, but did not show a similar trend to the positive control, and was therefore judged to be a suspected negative sample. Compared with the Kato-Katz method and the semi-nest PCR method, The sensitivity of the fluorescent RPA method were 100.00% and the specificity were 94.44%, and the consistency of the detection results was good (Kappa=0.953>0.75). Conclusions The assay based on the fluorescence RPA is an efficient, sensitive and specific technique for detecting Necator americanus and it can be applied for surveillance and early warning of hookworm infection.
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ABSTRACT Background: The World Health Organization recommends a market-ready, urine-based point-of-care diagnostic test for circulating cathodic antigens (CCA) to determine the prevalence of S. mansoni. This study evaluated the performance of the URINE CCA (SCHISTO) ECO TESTE® (POC-ECO), which is currently available in Brazil. Methods: Residents from eight sites with different prevalence estimates provided one urine sample for POC-ECO and one stool sample for Kato-Katz (KK) and Helmintex® (HTX) testing as an egg-detecting reference for infection status. Results: None of the study sites had significantly higher POC-ECO accuracy than KK. Conclusions: POC-ECO is not currently recommended in Brazilian schistosomiasis elimination programs.
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ABSTRACT Background The World Health Organization recommends reliable point-of-care (POC) diagnostic testing to eliminate schistosomiasis. Lateral flow immunoassay that detects schistosome circulating cathodic antigen (CCA) in urine to establish prevalence thresholds for intervention in endemic areas is recommended. Stored urine may be useful if surveying at-risk populations is delayed or interrupted by unforeseen circumstances, such as the current COVID-19 pandemic. This study evaluated the manufacturer's claim that Schistosoma mansoni infection can be reliably diagnosed in urine samples stored at -20°C for one year. Methods Two-hundred-forty-two subjects from an endemic site in Brazil provided one urine sample each for testing with URINE CCA (SCHISTO) ECO TESTE® (POC-ECO) and one stool sample each for testing with Kato-Katz (KK) and Helmintex® (HTX) as a robust reference standard for infection status. At least 2 ml of urine from each participant was stored at -20°C; after one year, 76 samples were randomly selected for POC-ECO retesting. Results: The POC-ECO agreement between freshly collected and stored urine was inadequate considering trace results as positive (Cohen's kappa coefficient κ = 0.08) and negative (κ = 0.36). POC-ECO accuracy was not significantly greater than that of routine KK (54%; 95% confidence interval: 42.1%-65.5%). Conclusions The precision and accuracy of POC-ECO have to be optimized in both freshly collected and stored urine before it can be recommended for use in control programs in Brazil.
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Abstract INTRODUCTION Schistosomiasis is a poverty-related disease that affects people in 78 countries worldwide. This study aimed to evaluate the point-of-care circulating cathodic antigen (POC-CCA) test performance using sensitive parasitological methods as a reference standard (RS) in individuals before and after treatment. METHODS The RS was established by combining the results of 16 Kato-Katz slides and the Helmintex® method. Positivity rates of the POC-CCA test and Kato-Katz and Helmintex® methods were calculated before treatment and 30 days afterward. Furthermore, the sensitivity, specificity, accuracy, and kappa coefficient before treatment were determined by comparing the methods. The cure rate was defined 30 days after treatment. RESULTS Among the 217 participants, the RS detected a total of 63 (29.0%) positive individuals. The POC-CCA test identified 79 (36.4%) infections. The evaluation of POC-CCA test performance in relation to the RS revealed a sensitivity of 61.9%, specificity of 74.0%, accuracy of 70.5%, and kappa coefficient of 0.33. Out of the 53 remaining participants after treatment, a total of 45 (81.1%) showed egg negative results, and 8 (18.9%) were egg positive according to the RS. A total of 5 (9.4%) egg-positive and 37 (69.8%) egg-negative individuals were positive by the POC-CCA test. CONCLUSIONS Our data show that the POC-CCA test has potential as an auxiliary tool for the diagnosis of Schistosoma mansoni infection, yielding better results than 16 Kato-Katz slides from three different stool samples. However, the immunochromatographic test lacks sufficient specificity and sensitivity for verifying the cure rate after treatment.
Subject(s)
Humans , Animals , Schistosoma mansoni/isolation & purification , Schistosomiasis mansoni/diagnosis , Schistosoma mansoni/immunology , Schistosomiasis mansoni/urine , Sensitivity and Specificity , Antigens, Helminth/bloodABSTRACT
Objective To establish an evaluation system for the field assessment of the Kato-Katz technique in detecting soiltransmitted nematodes, so as to provide insights into the field application of the Kato-Katz technique. Methods The initial evaluation indicators were determined through literature search, brainstorming and expert consultation. The evaluation indicatorswere improved and the weight of each indicator was decided through three rounds of expert consultation by using the Delphimethod. In addition, the expert authority coefficient and the coordination coefficient of each indicator were calculated at eachround of expert consultations. Results The recovery rates of the questionnaire were 100.00%, 100.00% and 89.29% at the firstto the third round of the expert consultations, respectively, and the expert authority coefficients were all more than 0.85 at eachround. The final evaluation system included 4 first-level indicators and 15 second-level indicators. In the first-level indicators, “detecting effect” and “funds investment” had the mean weighted value of 4.53 and 4.49, which were relatively higher than that of“person-time investment“ and "operability“ (both 4.34). Among the second-level indicators under each first-level indicator, thefour most significant indicators included “ability of personnel in egg discrimination“, “cooperation of village cadres and doctors“,“Person-time on testing“ and “organizational start-up cost“, with the mean weighted values of 4.74, 4.43, 4.39 and 4.17, respectively. The coordination coefficients were 0.39 to 0.65, 0.28 to 0.58 and 0.45 to 0.65 at the first to the third round of the expertconsultations, respectively, and there were significant differences in the coordination coefficients at all three rounds of the consultations (all P < 0.05). Conclusions An evaluation system for the field assessment of the Kato-Katz technique in detecting soiltransmitted nematodes is successfully established, among which “ability of personnel in egg discrimination“ and “cooperation ofvillage cadres and doctors“ have the greatest mean weighted values of the significance.
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Objective To compare the performance of modified Kato-Katz thick smear method (KK method) and PCR assay in field detection of Clonorchis sinensis in human fecal samples, which provides insight into the selection of tools for detecting C. sinensis. Methods Based on the epidemiological investigation of human C. sinensis infections in Tengxian County of Guangxi Zhuang Autonomous Region in 2016, a total of 133 fecal samples were randomly selected and stored at -20 ℃. All fecal samples were detected for C. sinensis infection using KK method and PCR assay, and the detection rate was compared between the two techniques. In addition, Kappa test was used to evaluate the consistency between the two methods. Results Among all fecal samples, the overall detection rate of C. sinensis was 77.44% (103/133), and the detection rate was significantly higher by PCR assay (70.68%, 93/133) than by KK method (57.14%, 76/133) (χ2 = 26.15, P < 0.01). There were 88.16% (67/76) of the microscopy-positive fecal samples positive for PCR assay, and 47.37% (27/57) of the microscopy-negative fecal samples positive for PCR assay. The detection rate of C. sinensis by PCR assay (94.74%, 18/19) was higher in fecal samples with EPG of > 1 000 than in samples with EPG of < 1 000 (85.96%, 49/57) (χ2 = 1.05, P = 0.436). The consistency of the detection rate of C. sinensis was moderate between the KK method and PCR assay (Kappa = 0.73). Conclusions The detection rate of C. sinensis by PCR assay is significantly higher than by KK method. In low-endemic areas of C. sinensis infections, the combination of KK method and PCR assay is suggested, so as to improve the detection rate.
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Objective To compare the performance of modified Kato-Katz thick smear method (KK method) and PCR assay in field detection of Clonorchis sinensis in human fecal samples, which provides insight into the selection of tools for detecting C. sinensis. Methods Based on the epidemiological investigation of human C. sinensis infections in Tengxian County of Guangxi Zhuang Autonomous Region in 2016, a total of 133 fecal samples were randomly selected and stored at -20 ℃. All fecal samples were detected for C. sinensis infection using KK method and PCR assay, and the detection rate was compared between the two techniques. In addition, Kappa test was used to evaluate the consistency between the two methods. Results Among all fecal samples, the overall detection rate of C. sinensis was 77.44% (103/133), and the detection rate was significantly higher by PCR assay (70.68%, 93/133) than by KK method (57.14%, 76/133) (χ2 = 26.15, P < 0.01). There were 88.16% (67/76) of the microscopy-positive fecal samples positive for PCR assay, and 47.37% (27/57) of the microscopy-negative fecal samples positive for PCR assay. The detection rate of C. sinensis by PCR assay (94.74%, 18/19) was higher in fecal samples with EPG of > 1 000 than in samples with EPG of < 1 000 (85.96%, 49/57) (χ2 = 1.05, P = 0.436). The consistency of the detection rate of C. sinensis was moderate between the KK method and PCR assay (Kappa = 0.73). Conclusions The detection rate of C. sinensis by PCR assay is significantly higher than by KK method. In low-endemic areas of C. sinensis infections, the combination of KK method and PCR assay is suggested, so as to improve the detection rate.
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Background: Soil-transmitted helminthiasis (STH) is a major public health problem in tropical areas such as the Philippines. A significant portion of the population in the Philippines consists of people located in the provinces as well as hard to reach localities that often cater to fishing and rural communities. Objectives: This study determined the prevalence of intestinal helminth infections, helminth densities, and relevant risk factors associated with helminth infections among grade school children. Materials and Methods: In July 2015, the prevalence of soil-transmitted helminths among Kindergarten to Grade 10 pupils in Jaime Hilario Integrated School-La Salle (JHIS-LS) in Bagac, Bataan, Philippines was determined using Kato-Katz technique. Moreover, socio-demographic profile including sex, age, and hygiene and sanitation practices of the pupils were obtained. Results: Of the 110 pupils, a prevalence rate of 6.36% with at least one STH infection was identified. The predominant parasites were Trichuris trichiura (56%), Ascaris lumbricoides (22%) and Enterobius vermicularis (22%). T. trichiura was identified in single infection while A. lumbricoides and E. vermicularis were found in mixed infections. Of the socio-demographic characteristics of the pupils, the use of soap in washing hands is a protective factor against helminth infections (OR=0.15, 95% CI: 0.02-0.97). Conclusion: Further studies using different STH diagnostic procedures must be done and other risk factors associated with STH must be identified.
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The criteria for the Kato-Katz thick smear are compiled following the Management Measures for Health Criteria and GBT 1.1–2009 Standardization Working Guidelines. The criteria are composed of five chapters, including the range of application, terms and definitions, equipments, reagent materials, and testing procedures. Three informative appendices (identification of helminth eggs in human faeces, counting method of eggs in Kato-Katz thick smear, and other considerations) are appended. The criteria have been issued by the National Health and Family Planning Commission of the People’s Republic of China, it provides a technical reference for the detection of helminth eggs in human faeces in medical institutions and disease prevention and control institutions.
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The criteria for the Kato-Katz thick smear are compiled following the Management Measures for Health Criteria and GBT 1.1–2009 Standardization Working Guidelines. The criteria are composed of five chapters, including the range of application, terms and definitions, equipments, reagent materials, and testing procedures. Three informative appendices (identification of helminth eggs in human faeces, counting method of eggs in Kato-Katz thick smear, and other considerations) are appended. The criteria have been issued by the National Health and Family Planning Commission of the People’s Republic of China, it provides a technical reference for the detection of helminth eggs in human faeces in medical institutions and disease prevention and control institutions.
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RESUMEN Introducción: Las parasitosis intestinales causadas por geohelmintos son consideradas un problema de salud pública que afectan principalmente a países en va de desarrollo y son proclives a presentarse en población infantil. Los métodos diagnósticos para identificar estas entidades parasitarias son el coprológico directo y las técnicas de concentración. El método establecido por la Organización Mundial de la Salud-OMS para identificar y cuantificar geohelmintiasis es el Kato-Katz; sin embargo, este no permite realizarse en trabajos de campo con periodos de tiempo prolongados, debido a que su análisis debe llevarse a cabo en las primeras 48 horas de toma de la muestra de materia fecal. Objetivo: Implementar el uso del fijador SAF (Acetato de sodio - Ácido acético - Formaldehído) en la técnica de Kato-Katz-OMS y evaluar la estabilidad de las estructuras de las entidades parasitarias, después de un periodo de doce meses de toma muestra y realizar comparación con la técnica de concentración Ritchie-Frick modificada (formol-gasolina), para determinar los valores de sensibilidad-S, especificidad-E, valor predictivo positivo-VPP y negativo-VPN y determinar la prevalencia del parasitismo intestinal y sus posibles variables asociadas en la comunidad infantil en edad preescolar y escolar del municipio de Chaguaní Cundinamarca. Materiales y Métodos: Se analizaron 67 muestras correspondientes a toda la población infantil en edad preescolar y escolar del área urbana del municipio de Chaguaní Cundinamarca, las cuales fueron valoradas por los métodos de Kato-Katz-SAF y concentración de Ritchie-Frick modificada (formol-gasolina) y posterior análisis microscópico. Resultados: La prevalencia de geohelmintiasis fue de 46,3%, la técnica de Kato-Katz-SAF presentó valores de S, E, VPP y VPN del 100% y la técnica de concentración de Ritchie-Frick modificada (formol-gasolina) S 60,8%, E y VPP 100% respectivamente y VPN 62,1%; la prevalencia para protozoos por este método fue de 65,7% hallándose agentes etiológicos patógenos y de carácter zoonótico. Se identificó que las variables onicofagia, consumo de agua sin proceso de cloración o hervido, presencia de vectores mecánicos, convivencia con animales domésticos como caninos, hacinamiento en la vivienda y uso poco frecuente de calzado, son variables de posible asociación estadística con la presencia de entidades parasitarias. Se determinó nivel de parasitemia por geohelmintiasis leve para esta población. Conclusión: El estudio reveló que el uso del reactivo de SAF puede implementarse en trabajos de campo prolongados conservando los estadios infectivos de las entidades geohelmínticas como: Ascaris lumbricoides, Trichuris trichiura y Uncinarias por un periodo de hasta doce meses.
ABSTRACT Introduction: The intestinal parasitic diseases caused by geohelminths are considered a public health problem that primarily affect developing countries and are likely to occur in children. The diagnostic methods to identify these parasitic entities are the direct stool and concentration techniques. The method established by the World Organization of the Health-WHO to identify and quantify geohelmintiasis is the Kato-Katz; however, this does not occur in fieldwork with long periods of time, since analysis should be performed in the first 48 hours of the sampling of fecal matter. Objective: Implement the use of SAF fixative (sodium acetate - acetic acid - formaldehyde) in the technique of Ka-to-Katz-WHO and to assess the stability of the structures of the entities parasitic, after a period of twelve months of taking shows and make comparison with the technique of modified Ritchie-Frick (formol-gasoline) concentration, to determine the values of sensitivity-S, specificity-E, predictive value PPV-positive and negative-VPN and determine the prevalence of intestinal parasitism and its possible variables associated in the infant community preschool and in schools of the municipality of Chaguanín Cundinamarca. Materials and methods: 67 samples corresponding to the entire child population at preschool and school age of the urban area of the municipality of Chaguani in Cundinamarca, which were valued by the methods of Kato-Katz-SAF and concentration of modified Ritchie-Frick (formol-gasoline) and subsequent microscopic analysis. Results: The prevalence of geohelmintiasis was 46.3%, the technique of Kato-Katz-SAF presented values of S, E, VPP, and 100% and VPN technique of concentration of modified Ritchie-Frick (formol-gasoline) 60.8% S, E and VPP 100% respectively and VPN 62.1%; the prevalence for protozoa by this method was 65.7% being etiologic agents pathogenic and zoonotic character. It was identified as variables onicofagia, consumption of water without boiling or chlorination process, the presence of mechanical vectors, coexistence with domestic animals such as dogs, overcrowded housing and less frequent use of footwear, are variables of possible statistical association with the presence of parasitic entities. Level of parasitemia was determined by mild geohelmintiasis for this population. Conclusion: Study revealed that the use of SAF reagent can be deployed in field work extended to conserving the infective stages of entities as geohelminths: Ascaris lumbricoides, Trichuris trichiura and hookworms for a period of up to twelve months.
RESUMO Introdução: As doenças parasitárias intestinais causadas por geohelmintos são consideradas um problema de saúde pública que afeta principalmente os países em desenvolvimento e é provável que ocorram em crianças. Os métodos de diagnóstico para identificar essas entidades parasitas são as fezes diretas e as técnica de concentração. O método estabelecido pela Organização Mundial da Saúde-OMS para identificar e quantificar geohelmintiasis é o Kato-Katz; No entanto, isso não ocorre no trabalho de campo com longos períodos de tempo, uma vez que a análise deve ser realizada nas primeiras 48 horas da amostragem de matéria fecal. Objetivo: Implementar o uso de fixador SAF (acetato de sódio - ácido acético - formaldeído) na técnica de Kato-Katz-OMS e avaliar a estabilidade das estruturas das entidades parasitárias, após um período de doze meses de exibição e exibição comparação com a técnica de concentração modificada de Ritchie-Frick (formol-gasolina), para determinar os valores de sensibilidade-S, especificidade-E, valor preditivo PPV-positivo e VPN negativo e determinar a prevalência de parasitismo intestinal e suas possíveis variáveis associadas na comunidade pré-escolar da comunidade infantil e nas escolas do município de Chaguanín Cundinamarca. Materiais e métodos: 67 amostras correspondentes a toda a população infantil na idade pré-escolar e escolar da área urbana do município de Chaguani em Cundinamarca, que foram avaliadas pelos métodos de Kato-Katz-SAF e concentração de Ritchie-Frick modificado (formol -gasolina) e posterior análise microscópica. Resultados: A prevalência de geohelmintiasis foi de 46,3%, a técnica de Kato-Katz-SAF apresentou valores de S, E, VPP e 100% e VPN de concentração de Ritchie-Frick modificada (formol-gasolina) 60,8% S, E e VPP 100% respectivamente e VPN 62,1%; A prevalência de protozoários por este método foi de 65,7% sendo agentes etiológicos patogênicos e de caráter zoonótico. Identificou-se como variáveis onicofagia, consumo de água sem processo de ebulição ou cloração, presença de vetores mecânicos, coexistência com animais domésticos, como cães, carcaça superlotada e uso menos freqüente de calçados, variáveis de possível associação estatística com a presença de parasitas entidades. O nível de parasitemia foi determinado por geohelmintiasis leve para esta população. Conclusão: O estudo revelou que o uso do reagente SAF pode ser implantado em trabalhos de campo estendidos para conservar os estádios infecciosos das entidades como geohelminas: Ascaris lumbricoides, Trichuris trichiura e ancilostomídeos por um período de até 12 meses.
Subject(s)
Humans , Child, Preschool , Diagnosis , Child, Preschool , Colombia , Intestinal Diseases, ParasiticABSTRACT
Abstract INTRODUCTION: This study analyzed the performance of the Kato Katz technique in detecting intestinal schistosomiasis in the State of Pará. METHODS: Of three stool samples provided by each of 380 participants, a total of 16 Kato Katz slides were examined to define the reference value (RV) of positives for comparisons. RESULTS: The RV revealed 37 (9.7%) infected participants in contrast to 10 (2.6%) according to a single slide. CONCLUSIONS: This significant underestimation of the infection rate gives reason to discuss if the current classification of prevalence levels reflects the real situation, principally in low transmission areas, like the Amazon region.
Subject(s)
Humans , Schistosomiasis mansoni , Feces/parasitology , Parasite Egg Count , Reference Values , Schistosomiasis mansoni/epidemiology , Prevalence , Predictive Value of Tests , Sensitivity and SpecificityABSTRACT
Abstract INTRODUCTION: Despite the advances of disease control programs, severe forms of schistosomiasis are prevalent. The prevalence of the disease in areas frequented by tourists urges for permanent prevention and control. The aim of this study was to describe the morbidity of schistosomiasis in the district of Antônio Pereira, Ouro Preto, Minas Gerais, Brazil. METHODS: The proportion of positives was defined by Kato-Katz coproscopy and urinary POC-CCA rapid test. Hepatosplenic form was diagnosed using abdominal ultrasound. RESULTS: Out of 180 participants,97 were examined by Kato-Katz, with 4 (4.1%) being positive. Thirty-four (22.1%) out of 154 were positive by POC-CCA. Five (2.8%) of 177 examined by ultrasound had hepatosplenic form. One of them had undergone splenectomy. One (0.6%)participant had myeloradiculopathy. CONCLUSIONS: Severe forms of schistosomiasis are still prevalent in low endemic areas and should be thoroughly investigated.
Subject(s)
Humans , Animals , Male , Female , Schistosoma mansoni/isolation & purification , Splenic Diseases/epidemiology , Schistosomiasis mansoni/epidemiology , Liver Diseases, Parasitic/epidemiology , Splenic Diseases/parasitology , Splenic Diseases/diagnostic imaging , Schistosomiasis mansoni/diagnosis , Prevalence , Cross-Sectional Studies , Morbidity , Educational Status , Feces/parasitology , Liver Diseases, Parasitic/parasitology , Liver Diseases, Parasitic/diagnostic imaging , Antigens, Helminth/urineABSTRACT
Platynosomiasis is a parasitic infection reported in non-human primates, including marmosets, and is frequently difficult to diagnose. In this study, the Kato-Katz method and the spontaneous sedimentation method were evaluated for their usefulness in identifying Platynosomum eggs in fecal samples from Callithrix penicillata that naturally harbor Platynosomum illiciens. Spontaneous sedimentation allowed the diagnosis of 41.7% (5/12) and 66.7% (8/12) of infected marmosets from one and three slides, respectively, prepared from the same fecal sample. The examination of a single Kato-Katz thick smear detected 83.3% (10/12) of infection cases. The analysis of feces on three different days increased the rate of diagnosis, since 75% (9/12) and 100% (12/12) of the primates with platynosomiasis were identified using serial spontaneous sedimentation (3 slides/day) and the Kato-Katz method, respectively. The mean number of Platynosomum eggs per gram of feces determined via the Kato-Katz method was 71.7 (8-240). The spontaneous sedimentation method when performed in series is acceptable for the diagnosis of platynosomiasis. However, the Kato-Katz method, which was here used for the first time to detect this infection, has a higher diagnostic sensitivity and the advantage that a quantitative analysis of the eggs released in the host feces is possible.
A platinossomose é uma infecção parasitária relatada em primatas não-humanos, inclusive saguis, cujo diagnóstico é frequentemente difícil. Neste estudo, os métodos de sedimentação espontânea e Kato-Katz foram avaliados quanto à sua utilidade na identificação de ovos de Platynosomum em amostras fecais de Callithrix penicillata naturalmente albergando Platynosomum illiciens. A sedimentação espontânea permitiu o diagnóstico de 41,7% (5/12) e 66,7% (8/12) dos saguis infectados a partir da análise de uma e três lâminas, respectivamente, preparadas de uma mesma amostra fecal. O exame de uma única lâmina de Kato-Katz detectou 83,3% (10/12) dos casos de infecção. A análise de fezes em três dias diferentes aumentou as taxas de diagnóstico, uma vez que 75% (9/12) e 100% (12/12) dos primatas que apresentaram a platinossomose foram identificados, usando-se a sedimentação espontânea (três lâminas/dia) e o Kato-Katz em série, respectivamente. O número médio de ovos de Platynosomum por g de fezes, determinado através do método de Kato-Katz, foi de 71,7 (8-240). O método de sedimentação espontânea, quando realizado em série, é aceitável para o diagnóstico da platinossomose. Entretanto, o método de Kato-Katz, o qual foi pela primeira vez usado para se detectar essa infecção, mostrou uma maior sensibilidade diagnóstica, com a vantagem de que é possível uma análise quantitativa dos ovos liberados nas fezes do hospedeiro.
Subject(s)
Humans , Hypertension/drug therapy , Hypertension/epidemiology , Drug Resistance , Hypertension/complications , Prognosis , Renal Insufficiency, Chronic/complicationsABSTRACT
Introduction: Schistosomiasis is a neglected chronic disease that affects mainly underdeveloped regions, including Brazil. Objective: To evaluate the distribution profile of the schistosomiasis in Divinópolis-MG. Material and methods: It is characterized as a descriptive and analytical epidemiological study. A parasitological study performed in schoolchildren of public municipal schools; simultaneously, a survey of schistosomiasis cases reported in the city between 2005 and 2011 years was performed with the Municipal Department of Health. Data related to the characteristics of the infection were observed, such as: affected areas, age, gender, and professional occupation. Results: This survey showed 33 cases of schistosomiasis in the city during this period, which the most of them (84.8%) were between 20-59 years of age. The results of the study with the schoolchildren are in agreement with those obtained through the reporting forms, both indicating no occurrence of schistosomiasis in individuals between 6-14 years of age in Divinópolis. Conclusion: The absence of the disease in children and adolescents analyzed and the presence in adults is a strong evidence of exogenous contamination in the city, especially as a result of immigration or rural tourism, and possible changes in habits, related to risk factors...
Introdução: A esquistossomose é uma doença crônica negligenciada, que afeta principalmente regiões subdesenvolvidas, incluindo o Brasil. Objetivo: Avaliar o perfil de distribuição da esquistossomose na região de Divinópolis-MG. Material e métodos: Caracteriza-se como um estudo epidemiológico analítico e descritivo. Foi realizado um estudo parasitológico em escolares da rede pública municipal e, concomitantemente, realizou-se também um levantamento dos casos notificados da doença no município entre 2005 e 2011, junto à Secretaria Municipal de Saúde. Foram verificados dados relacionados com as características da infecção, como regiões afetadas, faixa etária, gênero e ocupação profissional. Resultados: O levantamento apontou 33 casos de esquistossomose no município neste período, sendo a maior parte deles (84,8%) na faixa etária de 20 a 59 anos. Os resultados do estudo com os escolares estão em concordância com os obtidos por meio das fichas de notificação, ambos indicando a não ocorrência de esquistossomose em indivíduos de 6 a 14 anos em Divinópolis. Conclusão: A ausência da doença nas crianças e nos adolescentes analisados e a presença em adultos sugerem forte evidência de contaminação exógena no município, especialmente fruto de imigração ou turismo rural, além de possíveis mudanças de hábitos, relacionados com os fatores de risco...
Subject(s)
Humans , Male , Female , Child , Adolescent , Young Adult , Middle Aged , Disease Notification , Schistosomiasis/epidemiology , Students , Age Distribution , PrevalenceABSTRACT
This article presents an improvement to the Kato-Katz (KK) method, making it faster and more efficient for the visualisation of fertile eggs in stool samples. This modified KK method uses sodium acetate formalin as a fixative and reveals the intensity of infection in less than 1 h, reducing the diagnostic time without increasing the cost. This modified method may contribute to future epidemiological studies in both hospitals and the field due to its rapid and precise diagnostic, which allow for immediate treatment.
Subject(s)
Animals , Mice , Feces/parasitology , Parasite Egg Count/methods , Schistosoma mansoni/isolation & purification , Schistosomiasis mansoni/diagnosis , Diagnostic Tests, Routine , Sensitivity and SpecificityABSTRACT
The aim of this study was to evaluate the efficacy of a polymerase chain reaction (PCR)-based method to detect Schistosoma mansoni DNA in stool samples from individuals living in a low-endemicity area in Brazil. Of the 125 initial stool samples, 80 were ELISA reactive and eggs were identified in 19 of the samples by parasitological examination. For the PCR evaluations, 56 stool samples were selected and divided into five groups. Groups I-IV were scored negative for S. mansoni eggs by parasitological examination. Groups I and II were ELISA reactive, whereas Groups III and IV were ELISA nonreactive. Groups II and III were positive for other intestinal parasites. PCR testing scored eight samples as positive from these four groups. Group V represented the S. mansoni -positive group and it included ELISA-reactive samples that were scored positive for S. mansoni by one or more parasitological examinations (6/19 were positive by Kato-Katz method, 9/17 by saline gradient and 10/13 by Helmintex®). PCR scored 13 of these 19 samples as positive for S. mansoni . We conclude that while none of these methods yielded 100% sensitivity, a combination of techniques should be effective for improving the detection of S. mansoni infection in low-endemicity areas.
Subject(s)
Adolescent , Adult , Aged , Animals , Child , Child, Preschool , Humans , Middle Aged , Young Adult , DNA, Helminth/genetics , Feces/parasitology , Schistosoma mansoni/genetics , Schistosomiasis mansoni/diagnosis , Brazil , Polymerase Chain Reaction , Parasite Egg Count/methods , Sensitivity and Specificity , Schistosoma mansoni/isolation & purificationABSTRACT
Introducción: las parasitosis intestinales siguen siendo un problema de salud pública, que ha sido poco estudiado en Medellín, Colombia. Objetivo: determinar la frecuencia de parasitismo intestinal en habitantes de una comunidad marginal de Medellín y evaluar la validez, el desempeño, la eficiencia y la confiabilidad del examen directo en su diagnóstico. Materiales y métodos: estudio transversal y de evaluación de pruebas diagnósticas con fuente de información primaria. Se calcularon las proporciones con su intervalo de confianza y se hicieron pruebas de estadística no paramétrica y análisis de sensibilidad, especificidad, valores predictivos, razón de verosimilitud negativa y kappa. Resultados: la frecuencia global de parásitos, según el examen por concentración, fue 74,4%; la evaluación se hizo para parasitismo general y para las categorías protozoos, helmintos, comensales y patógenos; se hallaron sensibilidad superior al 68%, especificidad y valor predictivo positivo del 100%, valor predictivo negativo mayor de 74%, razón de verosimilitud negativa menor de 0,32, kappa superior a 0,77 y eficiencia superior al 90%. Conclusión: el problema del parasitismo intestinal amerita una pronta intervención por parte de las autoridades sanitarias dado que su frecuencia sigue siendo tan elevada como hace tres décadas y las pruebas disponibles para estudiarlo, incluyendo el examen directo de la materia fecal, tienen alto valor diagnóstico.
Background: Intestinal parasitism is still a public health problem. It has not been thoroughly studied in Medellin, Colombia. Objective: To determine the prevalence of intestinal parasites in residents of a marginal community in Medellin and to evaluate the validity, efficiency and reliability of direct examination in its diagnosis. Methods:Cross-sectional study and evaluation of diagnostic tests. Data were collected from a primary information source. Proportions with their confidence intervals were calculated; non-parametric statistical tests and analysis of sensitivity, specificity, predictive values, negative likelihood ratio and kappa were done. Results: Prevalence of parasites, according to the results of the concentration test, was 74.4%. Evaluation was done for intestinal parasites in general and for the following categories: protozoa, helminthes, commensals and pathogens. Sensitivity war over 68%, specificity and positive predictive value were 100%, negative predictive value was over 74%, negative likelihood ratio was less than 0.32, kappa was greater than 0.77 and efficiency was over 90%. Conclusion: Prevalence of intestinal parasitism is as high as it was three decades ago; its solution needs prompt and effective intervention of health authorities. The tests available for its study, including direct examination of stools, are of high diagnostic value.
Subject(s)
Humans , Parasitic Diseases , Poverty Areas , Intestinal Diseases, Parasitic , Public Health , Cross-Sectional Studies , DiagnosisABSTRACT
Introducción: La Fasciolosis es una enfermedad causada por el parásito Fasciola hepatica, que afecta primordialmente a bovinos, ovinos, caprinos y en algunas zonas de forma endémica a los humanos. En la investigación clínica y epidemiológica de fasciolosis humana es importante contar con técnicas coprológicas de diagnóstico de alta sensibilidad y especificidad. Objetivo: realizar la comparación de tres técnicas coprológicas para el diagnóstico de infección por Fasciola hepatica en humanos. Metodología: se procesaron 200 gramos de materia fecal de humanos contaminada experimentalmente con huevos de F. hepatica que se obtuvieron de análisis anteriores con muestras de ganado bovino y ovino. La muestra se dividió en 10 partes iguales; a cada una de estas muestras se les realizó la técnicas de Kato-Katz, técnica de sedimentación espontánea en tubo (TSET) y técnica de sedimentación rápida (TSR). Finalmente, la lectura de las muestras se basó en el diseño metodológico del doble ciego. Resultados: se encontró que la técnica de sedimentación rápida fue la más sensible de las tres evaluadas, detectándose positividad en 7,5 muestras de 10 analizadas; seguida por la técnica de Kato-Katz con 4,5 muestras y en último lugar la técnica de sedimentación espontánea en Tubo que mostró solo un resultado positivo. Conclusión: en este trabajo se encontró que la técnica de sedimentación rápida constituye la herramienta de elección para el profesional porque es la más sensible de las tres; además de ser sencilla, económica y de fácil aplicación en laboratorios de niveles uno y dos de complejidad para realizar un diagnóstico satisfactorio de fasciolosis humana. Salud UIS 2012; 44 (3): 7-12.
Introduction: fasciolosis is a disease caused by the parasite Fasciola hepatica wich primarily affects cattle, sheep, and goats. In certain areas, it is endemic for human beings. In clinical and epidemiological research of human fasciolosis is important to get diagnostic techniques with high sensibility and specificity. Objective: perform the comparison between three coprological techniques for the diagnosis of infection by F. hepatica in humans. Methods: 200 grams of human feces were experimentally contaminated with F. hepatica eggs obtained from previous analysis with cattle and sheep faecal samples. The preparation was divided into 10 equal parts, each one was processed by the Kato- Katz technique, the spontaneous tube sedimentation technique (STST) and rapid sedimentation technique (TSR). Finally, all samples reading was based on the double-blind study design. Results: we found out that TSR was the most sensitive of the three techniques tested: 7,5 of 10 samples analyzed were positive, followed by the Kato-Katz technique with 4.5 of 10 samples and TSET with only one of 10 samples. Conclusion: This study concludes that the rapid sedimentation technique is the tool of choice for professionals because it is simple, inexpensive and easily applied in laboratories with levels complexity one and two, for a successful diagnosis of human fasciolosis. Salud UIS 2012; 44 (3): 7-12.
ABSTRACT
Laboratory diagnosis of intestinal schistosomiasis mansoni can be accomplished through various methods of stool examination to detect parasites, ranging from the most classic tests (Kato-Katz) to several methods that are still undergoing validation. This study was conducted to assess two new parasite identification methods for diagnosing schistosomiasis mansoni in residents of a low endemic area in the municipality of Maranguape, in the state of Ceará, Brazil using the Kato-Katz method as a reference and serology (enzyme-linked immunosorbent assay) for the screening of patients. The Kato-Katz, the saline gradient method and the Helmintex® method parasite identification methods were employed only in subjects who exhibited positive serologic tests. The test results were then analysed and treatment of positive individuals was subsequently performed. After comparing the test results, we observed that the saline gradient method and the Helmintex® method were more effective in diagnosing schistosomiasis mansoni in the study area compared with the Kato-Katz method.