Comparison between the modified Ziehl-Neelsen and Acid-Fast-Trichrome methods for fecal screening of Cryptosporidium parvum and Isospora belli

Due to the importance of Cryptosporidium parvum, Cyclospora cayetanensis and Isospora belli as opportunistic parasites, it is essential for laboratories to morphologically differentiate these coccidia. Among the recommended methods for diagnosis of C. parvum and I. belli is the Modified Ziehl-Neelsen stain (MZN) and recently a new technique, the Acid-Fast-Trichrome (AFT) was proposed. The purpose of this study was to compare the AFT and MZN techniques regarding the detection of C. parvum and I. belli oocysts in stool samples of HIV-positive patients. According to the presence (n=60) or absence of diarrhea (n=60), two groups were selected for inclusion in this study. The stool samples were collected in 10% formalin solution and the pellets, obtained without and after centrifugation-concentration (500xg; 10 min), were submitted to both stain techniques. Considering the positivity of the techniques (AFT and MZN), we observed the superiority of MZN stain (n=19; 100% positive cases) over AFT (n=8; 42.1%). The identification of the 101 truly-negative cases was possible with both techniques, but when the AFT stain was used, the oocysts showed a variable inner stain degree, which resulted in false-negatives. Enteric coccidiosis was more frequent among the patients who presented diarrhea (26.6%) compared to asymptomatic individuals (5%); C. cayetanensis was not detected in these groups. We were interested in evaluating the employment of AFT for the Cyclospora oocyst stain. Based on the sensitivity and specificity obtained in this study (100%), we concluded that the MZN technique is still the most indicated for routine use in clinical analysis laboratories, for the diagnosis of cryptosporidiosis and isosporosis, especially when it was used together with the centrifugation procedure (500xg; 10 min). Our results showed that with some improvements, AFT would be a simple and inexpensive technique appropriate for use in the diagnosis of intestinal coccidia (C. parvum, C. cayetanensis and I. belli). It can also be extended to the detection of microsporidia.Devido a crescente importância dos coccídios intestinais (Cryptosporidium, Isospora e Cyclospora) como parasitos oportunistas, é fundamental para os laboratórios diferenciar morfologicamente estes protozoários; a técnica de Ziehl-Neelsen modificada (ZNm) é amplamente utilizada para este fim; recentemente, foi proposto um novo procedimento, a coloração combinada do ácido tricrômico (Acid-Fast-Trichrome - AFT). O objetivo do presente estudo foi comparar os processos AFT e ZNm para a detecção destes coccídios em amostras fecais de pacientes portadores do vírus VIH. Foram selecionados dois grupos de indivíduos, para inclusão no estudo, segundo a presença (n=60) ou ausência de diarréia (n=60). As amostras de fezes foram coletadas em solução de formalina 10% e os esfregaços fecais preparados i) diretamente das fezes e ii) após concentração prévia a 500xg (10 minutos), foram submetidos aos diferentes processos de coloração. Considerando-se a positividade por técnica (AFT e ZNm), verificou-se a superioridade do procedimento de ZNm (n=19; 100% dos casos positivos) sobre o de AFT (n=8; 42,1%). Ambos possibilitaram a identificação dos 101 casos verdadeiramente negativos. Coccidiose intestinal foi mais frequente entre os pacientes que apresentaram diarréia (26,6%) em comparação à positividade observada entre os indíviduos assintomáticos (5%) sendo que C. cayetanensis não foi detectada em ambos os grupos. Foi de nosso interesse avaliar a aplicabilidade da técnica AFT para a coloração deste protozoário. Devido à sensibilidade e especificidade obtida neste estudo (100%), conclui-se que o método de ZNm continua sendo o mais indicado para o diagnóstico da criptosporidiose e isosporose, principalmente quando associado ao procedimento de centrífugo-concentração (500xg, 10 minutos). Embora a coloração AFT tenha baixo custo, faz-se necessário o seu aperfeiçoamento pois este procedimento permite o diagnóstico simultâneo dos coccídios intestinais (C. parvum, I. belli e C. cayetanensis) e dos microsporídios.20921

[comparison Between The Modified Ziehl-neelsen And Acid-fast-trichrome Methods For Fecal Screening Of Cryptosporidium Parvum And Isospora Belli].

Due to the importance of Cryptosporidium parvum, Cyclospora cayetanensis and Isospora belli as opportunistic parasites, it is essential for laboratories to morphologically differentiate these coccidia. Among the recommended methods for diagnosis of C. parvum and I. belli is the Modified Ziehl-Neelsen stain (MZN) and recently a new technique, the Acid-Fast-Trichrome (AFT) was proposed. The purpose of this study was to compare the AFT and MZN techniques regarding the detection of C. parvum and I. belli oocysts in stool samples of HIV-positive patients. According to the presence (n=60) or absence of diarrhea (n=60), two groups were selected for inclusion in this study. The stool samples were collected in 10% formalin solution and the pellets, obtained without and after centrifugation-concentration (500xg; 10 min), were submitted to both stain techniques. Considering the positivity of the techniques (AFT and MZN), we observed the superiority of MZN stain (n=19; 100% positive cases) over AFT (n=8; 42.1%). The identification of the 101 truly-negative cases was possible with both techniques, but when the AFT stain was used, the oocysts showed a variable inner stain degree, which resulted in false-negatives. Enteric coccidiosis was more frequent among the patients who presented diarrhea (26.6%) compared to asymptomatic individuals (5%); C. cayetanensis was not detected in these groups. We were interested in evaluating the employment of AFT for the Cyclospora oocyst stain. Based on the sensitivity and specificity obtained in this study (100%), we concluded that the MZN technique is still the most indicated for routine use in clinical analysis laboratories, for the diagnosis of cryptosporidiosis and isosporosis, especially when it was used together with the centrifugation procedure (500xg; 10 min). Our results showed that with some improvements, AFT would be a simple and inexpensive technique appropriate for use in the diagnosis of intestinal coccidia (C. parvum, C. cayetanensis and I. belli). It can also be extended to the detection of microsporidia.35209-1

Giardiose e criptosporidiose em creches no município de Campinas, SP

Estudou-se as prevalências de Gíardia duodenalís e Cryptosporidium parvum, conforme sexo e faixa etária. em crianças de 2-60 meses (n = 310), atendidas em 8 creches. Giardiose ocoireu em 42 (13,5%) das crianças e foi mais freqüente na faixa etãria de 19-24 meses, embora crianças nos primeiros seis meses de vida apresentassem amostras fecais positivas. Teste estatístico não revelou associação entre sexo e parasitismo (p > 0,05). C. parvum foi encontrado em 20 crianças (6,4%) com maior frequência no grupo de 7-12 meses. Crianças entre 25-30 meses e acima de 36 meses não apresentaram oocistos nas fezes. Oocistos foram detectados em 4 crianças na faixa etãria de 0-6 meses. Não houve significância estatística entre criptosporidiose e sexo (p = 0,09) e, entre creches (p = 0,068). Ocorreu associação entre idade e a presença do coccídio (p = 0,004). Abordou-se os aspectos epidemiológicos por meio de inquérito familiar, exames parasitolõgicos entre contatos dos casos-índices e dos animais presentes no domicílio. Prevalência de C. parvum foi maior quando pelo menos um dos pais era profissional da Área de Saúde (73,6% positivas), hai:ia relato de doença concomitante (52,6%) positivas) e diairéia era o principal sintoma por ocasião de exame fecal (78,9%) positivas). Exames de fezes dos animais domésticos foram negativos para estes dois parasitos.<br>The prevalence of the Giardia duodenalis and Cryptosporidium parvum infections were studied in children 2-60 months old (n = 310) grouped to sex and age, enrolled in 8 day-care centers. Giardiosis was found in 42 (13.5%) of the children and, was most frequent in the age group corresponding to 19- 24 months old although children at the first six months of life also presented positive faecal samples. Statistical analysis indicated no association between sex ip > 0,05) and prevalence for Giardia infection. C. parvum was detected in 20 (6.4%) of the children. Children seven to twelve months old showed the greatest prevalence of this parasite. There were not oocysts in the stools from the children 25-30 months and from those older than 36 months. Oocysts were detected in 4 children from the 0-6 months old group. There was no significative difference on sex (p = 0,09) and day-care facility (p = 0,068) for C. parvum infection while age was associated with infection (p = 0,004). Epidemiological aspects were studied by familiar inquiry, by parasitological examinations of stools from the contact- members of each case and from animals present at the residence. Prevalence for C. parvum was higher when at least one of the parents was a professional in the Human Health Centers (73.6% positives), when there was report of concomitant disease (52.6%positives) and when diarrhoea was the main symptom at the collection of the faecal specimens (78.9% positives). Faecal examinations of the domestic animals were negatives for these two parasites

Deep Underground Neutrino Experiment (DUNE), Far Detector Technical Design Report, Volume II: DUNE Physics

The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay -- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. DUNE is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. Volume II of this TDR, DUNE Physics, describes the array of identified scientific opportunities and key goals. Crucially, we also report our best current understanding of the capability of DUNE to realize these goals, along with the detailed arguments and investigations on which this understanding is based. This TDR volume documents the scientific basis underlying the conception and design of the LBNF/DUNE experimental configurations. As a result, the description of DUNE's experimental capabilities constitutes the bulk of the document. Key linkages between requirements for successful execution of the physics program and primary specifications of the experimental configurations are drawn and summarized. This document also serves a wider purpose as a statement on the scientific potential of DUNE as a central component within a global program of frontier theoretical and experimental particle physics research. Thus, the presentation also aims to serve as a resource for the particle physics community at large

Deep Underground Neutrino Experiment (DUNE), Far Detector Technical Design Report, Volume I Introduction to DUNE

International audienceThe preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay—these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. This TDR is intended to justify the technical choices for the far detector that flow down from the high-level physics goals through requirements at all levels of the Project. Volume I contains an executive summary that introduces the DUNE science program, the far detector and the strategy for its modular designs, and the organization and management of the Project. The remainder of Volume I provides more detail on the science program that drives the choice of detector technologies and on the technologies themselves. It also introduces the designs for the DUNE near detector and the DUNE computing model, for which DUNE is planning design reports. Volume II of this TDR describes DUNE's physics program in detail. Volume III describes the technical coordination required for the far detector design, construction, installation, and integration, and its organizational structure. Volume IV describes the single-phase far detector technology. A planned Volume V will describe the dual-phase technology