Infecciones por Clostridioides difficile en pediatría. La visión del laboratorio a partir del diagnóstico microbiológico / Clostridioides difficile infections in pediatrics. The view of the laboratory based on microbiological diagnosis

La infección por Clostridioides difficile (ICD) es la principal responsable de diarreas nosocomiales en adultos. En los últimos años se registró un aumento en la incidencia de la ICD en la población adulta que, en cambio, no fue bien caracterizado en pediatría. El objetivo de este trabajo es analizar los datos resultantes del diagnóstico microbiológico de ICD en el Hospital de Pediatría "Prof. Dr. Juan P. Garrahan". Materiales y métodos: se realizó un estudio retrospectivo observacional descriptivo que abarcó desde el 01/01/2018 hasta el 31/12/2021. El diagnóstico se realizó mediante enzimoinmunoensayo para glutamato deshidrogenasa (GDH) y toxinas en materia fecal (MF). Cuando sólo se detectó GDH, se realizó un cultivo toxigénico (CT) de la MF para la detección de toxinas in vitro. Se registraron: edad, sexo y procedencia de los pacientes y recurrencias de las ICD. Se efectuaron estudios de sensibilidad de 387 cepas de C. difficile a metronidazol (MTZ) y vancomicina (VAN). Resultados: en 6632 muestras (1764 pacientes) se registraron 649 estudios positivos (9,8%) (139 pacientes), la mayoría correspondieron a pacientes internados en áreas no críticas. Edad promedio: 7 años (7 ± 4,7). Sexo: 55% masculino. Recurrencias: 62 (45%). Positivos detectados mediante CT: 43%. Sensibilidad antibiótica: 100% a MTZ y 99,7% a VAN. Conclusión: Nuestra población presenta un bajo porcentaje de positividad. Se destaca el rendimiento del CT que permitió el diagnóstico de más de un tercio de los casos. MTZ y VANCO tuvieron excelente actividad in vitro frente a C. difficile (AU)

Clostridioides difficile infection (CDI) is the main cause of nosocomial diarrhea in adults. In recent years there has been an increase in the incidence of CDI in the adult population; however, CDI has not been well characterized in pediatrics. The aim of this study was to analyze the data resulting from the microbiological diagnosis of CDI at Hospital de Pediatría Prof. Dr. Juan P. Garrahan. Materials and methods: a retrospective, observational and descriptive study was conducted from 01/01/2018 to 12/31/2021. Diagnosis was made using enzyme immunoassay for glutamate dehydrogenase (GDH) and toxins in stools. When only GDH was detected, toxigenic culture (TC) of stools was performed for in vitro toxin detection. The age, sex and origin of patients and CDI recurrences were recorded. Sensitivity studies of 387 strains of C. difficile to metronidazole (MTZ) and vancomycin (VAN) were performed. Results: In 6,632 samples (1,764 patients), 649 positive results (9.8%) were recorded (139 patients), most of which corresponded to patients hospitalized in noncritical areas. Mean age: 7 years (7 ± 4.7). Sex: 55% male. Recurrences: 62 (45%). TC-positive results: 43%. Antibiotic sensitivity: 100% to MTZ and 99.7% to VAN. Conclusion: A low percentage of positivity was found in our population. The performance of TC was outstanding, allowing for the diagnosis of more than one third of the cases. MTZ and VANCO had excellent in vitro activity against C. difficile (AU)

Padronização de um ELISA indireto a partir da utilização de uma proteína de superfície do vírus da anemia infecciosa equina como antígeno para o diagnóstico dessa enfermidade / Standardization of an indirect ELISA using a surface protein of the equine infectious anemia virus as an antigen for the diagnosis of this disease

A anemia infecciosa equina é uma importante enfermidade que acomete os equídeos em todo o mundo, se apresentando de forma aguda, crônica e assintomática causando grandes prejuízos para a economia tanto para criadores que vivem do trabalho desses animais quantos aos criadores que investem no melhoramento das raças, impedindo o acesso ao mercado tanto nacional quanto internacional. O Ministério da Agricultura, Pecuária e Abastecimento considera o IDGA como teste oficial para diagnóstico dessa enfermidade, porém essa técnica é demorada e muita vez acaba sendo subjetiva, dependendo da experiencia particular de cada Laboratorista. Além de não conseguir detectar animais no início da infecção. Logo, a necessidade de se buscar novas técnicas como o ELISA indireto que aperfeiçoem o tempo de análise dos resultados, facilita a automação e obtém resultados confiáveis. O estudo realizado teve como objetivo padronizar uma técnica de ELISA indireto utilizando uma proteína de envelope viral GP90 como antígeno para diagnóstico da anemia infecciosa equina. Avaliando o desempenho do teste a partir da sensibilidade, especificidade e valores preditivos positivo e negativo. Os valores obtidos foram: 91,11%, 93,33%, 91,11% e 93,33% respectivamente. Concluiu-se que o teste apresenta bom desempenho, além da possibilidade de detectar amimais positivos no início da infecção.

Equine infectious anemia is an important disease that affects horses all over the world, presenting in an acute, chronic and asymptomatic way, causing great damage to the economy, both for breeders who live off the work of these animals and for breeders who invest in the improvement of breeds, preventing access to both national and international markets. The Ministry of Agriculture, Livestock and Food Supply considers AGID to be the official test for diagnosing this disease, but this technique takes time and often ends up being subjective, depending on the particular experience of each laboratory worker. In addition to not being able to detect animals at the beginning of the infection. Therefore, the need to seek new techniques such as indirect ELISA that improve the time of analysis of results, facilitate automation and obtain reliable results. The aim of this study was to standardize an indirect ELISA technique using a GP90 viral envelope protein as an antigen for the diagnosis of equine infectious anemia. Evaluating test performance based on sensitivity, specificity and positive and negative predictive values. The values obtained were 91.11%, 93.33%, 91.11 and 93.33 respectively. It was concluded that the test performs well, in addition to the possibility of detecting positive animals at the beginning of the infection.

Verificación del desempeño general del método Elecsys® Chagas en la detección de anticuerpos específicos contra Trypanosoma cruzi / Verification of the general performance of the Elecsys® Chagas method in the detection of specific antibodies against Trypanosoma cruzi

Resumen La enfermedad de Chagas es una parasitosis producida por Trypanosoma cruzi, prevalente principalmente en el continente americano, y observada en regiones no endémicas, producto de viajes y migraciones. El objetivo de este estudio fue comparar el desempeño del ensayo Elecsys® Chagas (Roche Diagnostics Alemania) (ECLIA) para el diagnóstico de la infección chagásica crónica con el método estándar y evaluar su posible empleo en reemplazo del método automatizado existente. Se estudiaron 77 muestras de sueros pertenecientes a pacientes con diagnóstico presuntivo de enfermedad de Chagas, procesadas por los distintos métodos disponibles en la Sección Parasitología del Hospital Muñiz: inmunoensayo quimioluminiscente de micropartículas (CMIA) (Abbott), enzimoinmunoanálisis de adsorción (ELISA) (Wiener) y hemaglutinación indirecta (HAI) (Lab. Lemos S.R.L.). Los resultados de los métodos ELISA y HAI fueron comparados con los obtenidos en la prueba ECLIA, y estos a su vez con el método automatizado disponible. De las muestras analizadas, 22 (28,57%) presentaron IgG anti-T. cruzi y 55 (71,43%) resultaron negativas. Con el método ECLIA se logró un 100% en los parámetros de desempeño, con diferencias en los intervalos de confianza. La razón de verosimilitud positiva y la razón de verosimilitud negativa clasificaron al ensayo como excelente y la potencia global del test apoyó esa afirmación. Los métodos inmunológicos automatizados ayudan a la performance diagnóstica en la etapa crónica de la enfermedad de Chagas, permiten minimizar errores, favorecen la velocidad de emisión de los resultados y, debido a su alta sensibilidad y especificidad, en ciertos escenarios podrían proponerse para usar como única técnica.

Abstract Chagas disease is a parasitosis caused by Trypanosoma cruzi, prevalent mainly in the American continent, and observed in non-endemic regions as a result of travel and migration. The objective of this study was to compare the performance of the Elecsys® Chagas (Roche Diagnostics Alemania) (ECLIA) assay for the diagnosis of chronic Chagas infection with the diagnostic standard, and to evaluate its possible use as a replacement for the existing automated method. A total of 77 serum samples belonging to patients with a presumptive diagnosis of Chagas disease were evaluated, processed by the different methods available in the Parasitology Section of Hospital Muñiz: microparticle chemiluminescent immunoassay (CMIA) (Abbott), enzyme-linked immunosorbent assay (ELISA) (Wiener) and indirect hemagglutination (HAI) (Lab. Lemos S.R.L). The results of the ELISA and HAI methods were compared with those obtained in the ECLIA test, and these in turn with the available automated method. Of the samples analysed, 22 (28.57%) presented IgG anti-T. cruzi and 55 (71.43%) were negative. With the ECLIA method, 100% was achieved in the performance parameters, with differences in the confidence intervals. The positive likelihood ratio and the negative likelihood ratio classify the essay as excellent, and the overall power of the test supports this statement. Automated immunological methods help diagnostic performance in the chronic stage of Chagas disease, allow minimising errors, favour the speed of issuance of results, and due to the high sensitivity and specificity, in certain scenarios, they could be proposed for use as single technique.

Resumo A doença de Chagas é uma parasitose causada pelo Trypanosoma cruzi, prevalente principalmente no continente americano, e observada em regiões não endêmicas em decorrência de viagens e migrações. O objetivo deste estudo foi comparar o desempenho do ensaio Elecsys® Chagas (Roche Diagnostics Alemanha) (ECLIA) para o diagnóstico da infecção crônica de Chagas com o método padrão e avaliar seu possível uso em substituição do método automatizado existente. Foram avaliadas 77 amostras de soro pertencentes a pacientes com diagnóstico presuntivo de doença de Chagas, processadas pelos diferentes métodos disponíveis na Seção de Parasitologia do Hospital Muñiz: imunoensaio quimioluminescente de micropartículas (CMIA) (Abbott), ensaio imunoenzimático de adsorção (ELISA) (Wiener) e hemaglutinação indireta (HAI) (Lab. Lemos S.R.L). Os resultados dos métodos ELISA e HAI foram comparados com os obtidos no teste ECLIA, e estes por sua vez com o método automatizado disponível. Das amostras analisadas, 22 (28,57%) apresentaram IgG anti-T. cruzi e 55 (71,43%) foram negativos. Com o método ECLIA, foram obtidos 100% nos parâmetros de desempenho, com diferenças nos intervalos de confiança. A razão de verossimilhança positiva e a razão de verossimilhança negativa classificam o ensaio como excelente, e a potencia geral do teste conformou essa afirmação. Os métodos imunológicos automatizados auxiliam no desempenho diagnóstico na fase crônica da doença de Chagas, permitem minimizar erros, favorecem a rapidez na emissão dos resultados e, devido à alta sensibilidade e especificidade, em determinados cenários, poderiam ser propostos para uso como técnica única.

Clostridioides difficile: achados epidemiológicos em animais domésticos em um Hospital Veterinário Universitário em ­ Teresina, PI / Clostridioides difficile: epidemiological findings in domestic animals in a University Veterinary Hospital in Teresina, PI

O objetivo deste estudo foi analisar a prevalência de Clostridioides difficile e suas toxinas (A/B) nas fezes de animais domésticos de um Hospital Veterinário Universitário de Teresina - PI. A detecção de C. difficile e suas toxinas foi realizada por meio de um ensaio imunoenzimático, denominado C. Diff Quik Chek Complete® (TECHLAB), capaz de detectar antígeno Glutamato Desidrogenase (GDH) e as toxinas A/B produzidas pelo bacilo, realizado em amostras fecais de cães (C. lupus) e e gatos (Felis catus) coletadas entre agosto de 2019 a setembro de 2020. Um total de 54 amostras fecais foram analisadas, das quais 16 foram positivas para C. difficile (29,63%). 68,75% (11/16) pertenciam a caninos, enquanto 31,25% (5/16) a felinos. Amostras diarreicas e não diarreicas foram utilizadas para o estudo e uma maior prevalência do bacilo pôde ser identificada em amostras diarreicas (33%). Nenhuma das amostras apresentou toxinas do patógeno. Os achados deste estudo evidenciam que C.difficile está presente no estado do Piauí. Foi possível identificá-lo em todas as espécies e em amostras diarreicas ou não, demonstrando que essa infecção pode se manifestar de formasintomática e assintomática, levantando a possibilidade de infecção cruzada entre o animal e seu tutor.

The aim of this study was to analyze the prevalence of Clostridioides difficile and its toxins (A/B) in the feces of domestic animals at a University Veterinary Hospital in Teresina - PI. The detection of C. difficile and its toxins was performed by an immunogenic enzyme, called C. Diff Quik Chek Complete® (TECHLAB), capable of detecting antigen glutamate dehydrogenase (GDH) and A/B toxins produced by this bacillus, performed in fecal samples of dogs (C. lupus) and cats (Felis catus) collected between August 2019 and September 2020.:54 stools were analyzed, of which 16 were positive for C. difficile (29.63%). 68.75% (11/16) belonged to canines, while 3.25% (5/16) to felines. Diarrheal and non-diarrheal diseases are used for the study and a higher prevalence of bacillus can be identified in diarrheal diseases (33%). None of the samples present pathogen toxins. The results of this study show that C. difficile is present in the state of Piauí. It can be identified in all species and in diarrheal or non-diarrheic samples, demonstrating that this infection can be symptomatic and asymptomatic, giving the possibility of cross-infection between the animal and its owner.

Application of limiting antigen avidity enzyme immunoassay for estimating HIV-1 incidence in men who have sex with men / 中华流行病学杂志

Objective: To estimate the incidence of HIV-1 infection in men who have sex with men (MSM) in key areas of China through HIV-1 limiting antigen avidity enzyme immunoassay (LAg-Avidity EIA), analyze the deviation from the actual results and identify influencing factors, and provided reference for improving the accuracy of estimation results. Methods: Based on the principle of the cohort randomized study design, 20 cities were selected in China based on population size and the number of HIV-positive MSM. The sample size was estimated to be 700 according to the HIV-1 infection rate in MSM. MSM mobile phone app. was used to establish a detection appointment and questionnaire system, and the baseline cross-sectional survey was conducted from April to November 2019. LAg-Avidity EIA was used to identify the recent infected samples. The incidence of HIV-1 infection was calculated and then adjusted based on the estimation formula designed by WHO. The influencing factors were identified by analyzing the sample collection and detection processes. Results: Among the 10 650 blood samples from the participants, 799 were HIV-positive in initial screening, in which 198 samples (24.78%) missed during confirmation test. Only 621 samples were received by the laboratory. After excluding misreported samples, 520 samples were qualified for testing. A total of 155 samples were eventually determined as recent infection through LAg-Avidity EIA; Based on the estimation formula , the incidence of HIV-1 infection in MSM in 20 cities was 4.06% (95%CI:3.27%-4.85%), it increased to 5.53% (95%CI: 4.45%-6.60%)after the adjusting for sample missing rate. When the sample missing rate and misreporting rate were both adjusted, the incidence of HIV-1 infection in the MSM increased to 5.66% (95%CI:4.67%-6.65%). The actual incidence of HIV-1 infection in MSM in the 20 cities might be between 4.06% and 5.66%. Conclusions: Sample missing and misreporting might cause the deviation of the estimation of HIV-1 infection incidence. It is important to ensure the sample source and the quality of sample collection and detection to reduce the deviation in the estimation of HIV-1 infection incidence.

Serological and molecular detection of Theileria equi in horses from Sinop, Mato Grosso state, Brazil / Detecção sorológica e molecular de Theileria equi em equinos oriundos de Sinop, Mato Grosso, Brasil

Equine piroplasmosis is the most important tick-borne disease to affect horses in Brazil. Theileria equi is one of the causative agents of equine piroplasmosis. Chronic cases are expected, in which the animals show no apparent signs of infection and remain asymptomatic but constitute a source of the infectious agent that ticks can spread. This study was conducted across 81 ranches located in the municipality of Sinop, State of Mato Grosso, Brazil. A sample calculation was performed to estimate the apparent prevalence of T. equi among horses. A total of 1,853 animals were included in the sampling analysis based on the information available from the Institute of Agricultural and Livestock Defense of Mato Grosso State. The serological analysis of 367 serum samples using an indirect enzyme-linked immunosorbent assay (ELISA) to detect anti-T. equi antibodies revealed that 337 animals were positive, representing a frequency of 90.70%. The molecular analysis to amplify the EMA-1 gene showed positivity in 20 of 89 tested samples. The fragments of four samples were sequenced and analyzed to determine their similarities to sequences from other species, based on sequences deposited at GenBank. All showed 100% similarity with T. equi. Our study represents the first report of T. equi antibodies among the equids in north-central region of Mato Grosso, revealing the widespread distribution of seropositive animals.

A piroplasmose equina é a doença transmitida por carrapatos mais importante em cavalos no Brasil. Theileria equi é um dos agentes causadores da piroplasmose equina. São esperados casos crônicos, nos quais os animais não apresentam sinais aparentes de infecção e permanecem assintomáticos, mas constituem uma fonte de infecção e disseminação por carrapatos. Este estudo foi realizado em 81 fazendas localizadas no município de Sinop, Estado de Mato Grosso, Brasil. Um cálculo amostral foi realizado para estimar a prevalência aparente de T. equi entre cavalos. No total, 1.853 animais foram incluídos na análise amostral com base nas informações disponíveis no Instituto de Defesa Agropecuária do Estado de Mato Grosso. A análise sorológica de 367 amostras de soro por meio de ensaio imunoenzimático indireto (ELISA) para detecção de anticorpos anti-T. equi revelou que 337 animais eram positivos, representando uma frequência de 90,70%. A análise molecular para o gene EMA-1 mostrou positividade em 20 das 89 amostras testadas. Os fragmentos de quatro amostras foram sequenciados e analisados para determinar suas semelhanças com sequências de outras espécies, a partir das sequências depositadas no GenBank. Todos mostraram 100% de similaridade com T. equi. Nosso estudo representa o primeiro relato de anticorpos contra T. equi entre os equídeos na região centro norte de Mato Grosso, revelando a ampla distribuição de animais soropositivos.

Comparison between Enzyme Immunoassays Performed on Samples of Dried Blood and Serum for Toxoplasmosis Prenatal Screening: Population-based Study / Comparação entre ensaios imunoenzimáticos realizados em amostras de sangue seco e soro para triagem prénatal da toxoplasmose: Estudo populacional

Abstract Objective Most prenatal screening programs for toxoplasmosis use immunoassays in serum samples of pregnant women. Few studies assess the accuracy of screening tests in dried blood spots, which are of easy collection, storage, and transportation. The goals of the present study are to determine the performance and evaluate the agreement between an immunoassay of dried blood spots and a reference test in the serum of pregnant women from a population-based prenatal screening program for toxoplasmosis in Brazil. Methods A cross-sectional study was performed to compare the immunoassays Imunoscreen Toxoplasmose IgM and Imunoscreen Toxoplasmose IgG (Mbiolog Diagnósticos, Ltda., Contagem, Minas Gerais, Brazil)in dried blood spots with the enzymelinked fluorescent assay (ELFA, BioMérieux S.A., Lyon, France) reference standard in the serum of pregnant women from Minas Gerais Congenital Toxoplasmosis Control Program. Results The dried blood spot test was able to discriminate positive and negative results of pregnant women when comparedwith the reference test, with an accuracy of 98.2% for immunoglobulin G (IgG), and of 95.8% for immunoglobulin M (IgM). Conclusion Dried blood samples are easy to collect, store, and transport, and they have a good performance,making this a promisingmethod for prenatal toxoplasmosis screening programs in countries with continental dimensions, limited resources, and a high prevalence of toxoplasmosis, as is the case of Brazil.

Resumo Objetivo A maioria dos programas de triagem pré-natal para toxoplasmose utiliza imunoensaios em amostras de soro de gestantes. Poucos estudos avaliam a acurácia dos testes de triagem em amostras de sangue seco, que são de fácil coleta, armazenamento e transporte. Este estudo teve como objetivo determinar o desempenho e avaliar a concordância entre um imunoensaio em sangue seco e um teste de referência em soro de gestantes de um programa de rastreamento pré-natal de base populacional para toxoplasmose no Brasil. Métodos Realizou-se um estudo transversal para comparar os imunoensaios Imunoscreen Toxoplasmose IgM e Imunoscreen Toxoplasmose IgG (Mbiolog Diagnósticos, Ltda., Contagem, Minas Gerais, Brazil) em sangue seco com o padrão de referência ensaio fluorescente ligado a enzimas (enzyme-linked fluorescent assay, ELFA, BioMérieux S.A., Lion, França) no soro de gestantes do Programa de Controle de Toxoplasmose Congênita de Minas Gerais. Resultados O exame em sangue seco foi capaz de discriminar os resultados positivos e negativos das gestantes quando comparado ao teste de referência, com acurácia de 98,2% para imunoglobulina G (IgG), e de 95,8% para imunoglobulina M (IgM). Conclusão O sangue seco apresenta bom desempenho e é uma amostra de fácil coleta, armazenamento e transporte, o que o torna um método promissor para programas de triagem pré-natal de toxoplasmose em países com dimensões continentais, recursos limitados, e alta prevalência de toxoplasmose, como é o caso do Brasil.

Fauna flebotomínica e soroprevalência para leishmaniose visceral canina em área urbana na região Centro-Oeste do Brasil / [Phlebotomine fauna and seroprevalence for canine visceral leishmaniasis in urban area from Central-West region of Brazil]

A leishmaniose visceral americana (LVA) é uma zoonose de transmissão vetorial na qual o cão tem papel importante na epidemiologia da doença. No Brasil, a elevada prevalência da infecção em cães está diretamente correlacionada com o aumento no risco de ocorrência de casos de LVA. O objetivo deste estudo foi investigar a fauna flebotomínica e verificar a soroprevalência da leishmaniose visceral canina (LVC) na localidade Pedra 90, no município de Cuiabá. Para o levantamento entomológico, armadilhas CDC foram utilizadas de agosto de 2014 a julho de 2015. Na avaliação sorológica dos cães, o teste imunocromatográfico DPP LVC foi utilizado para a triagem das amostras, enquanto o ensaio imunoenzimático (EIE) para o diagnóstico da LVC (Bio-Manguinhos) foi empregado como teste confirmatório. O trabalho vem acrescentar à fauna flebotomínica do município de Cuiabá as espécies Lu. andersoni, Lu. braziliensis, Lu. bourrouli e Lu. scaffi, não registradas em publicações anteriores. Além disso, entre as espécies de flebotomíneos com importância médica, Lu. cruzi, Lu. flaviscutellata e Lu. whitmani foram capturadas. No inquérito canino, a prevalência de LVC observada na localidade Pedra 90 foi de 1,14%, indicando que a região pode ser considerada como área de transmissão.(AU)

American visceral leishmaniasis (AVL) is a vector-borne zoonosis in which the dog has an important role in the epidemiology of the disease. In Brazil, a high prevalence of canine infection is directly correlated with an increased risk of occurrence of AVL. The aim of this study was to investigate the phlebotomine fauna and seroprevalence of canine visceral leishmaniasis in Pedra 90 region of Cuiabá municipality. For the entomological survey, CDC traps were used from August 2014 to July 2015. In the serological evaluation of dogs, the immunochromatographic test DPP LVC was employed for screening the samples while enzyme-linked immunosorbent assay (Bio-Manguinhos) was used as a confirmatory assay. The previously unreported phlebotomine species Lu. andersoni, Lu. braziliensis, Lu. bourrouli, and Lu. scaffi were added to the phlebotomine fauna of Cuiabá. In addition, the medically important phlebotomine species Lu. cruzi, Lu. flaviscutellata, and Lu. whitmani were identified. The canine survey revealed the prevalence of 1.14% for canine visceral leishmaniasis in the Pedra 90 region, the region being considered a transmission area.(AU)

Measles, rubella, mumps and Toxoplasma gondii antibodies in saliva of vaccinated students of schools and universities in São Paulo City, Brazil

ABSTRACT Introduction: Vaccines are well-established public health interventions with major impacton the prevalence of infectious diseases, but outbreaks are occurring frequently due to pri-mary and secondary failures, despite high coverage. Surveillance of efficacy and duration ofinduced immunity is a difficult task as it requires invasive blood sampling in children andteenagers. Saliva can be an acceptable alternative source of IgG to assess vaccine efficacyand toxoplasmosis incidence. We investigated IgG response for measles, mumps, rubella,and T. gondii in saliva samples of vaccinated young people. Methods: Saliva was collected from 249 public schools students from São Paulo, Brazil, aged7 to 13 years old, during an interactive exhibition on hygiene. We used S. aureus proteinA solid phase capture assay for IgG reactive to biotinylated purified proteins. Paired salivaand serum (47) were tested from young adults with serum evidence of T. gondii infectionand from negative children less than 12 month old for standardization. Reproducibility wasgreater than 98% and sensitivity and specificity of the saliva assays were greater than 95%,as well as the concordance of paired saliva and serum samples. Results: Saliva from high school students showed a prevalence of 8.5% (95% CI: 5.0-11.9%)for anti T. gondii IgG; 96.8% (94.6-99%) of anti-measles IgG; 59.1% (53-65%) of anti-rubella IgG,and 57.5% (51.3-63.6%) of anti-mumps IgG. Discussion: The prevalence of antibodies against mumps and rubella after 6-8 years of vaccination was lower than against measles among students. The findings of this study demonstrate the feasibility of saliva sampling for follow-up of vaccine immune status in teenagers. This useful approach allows for IgG detection for vaccine control or epidemio- logical studies.

Avaliação do emprego de pool de soros na triagem de infecção por HTLV-1/2 / Evaluation of the use of serum pool in screening for HTLV-1/2 infection

Os vírus linfotrópicos de células T humanas dos tipos um e dois (HTLV-1 e HTLV-2) são endêmicos no Brasil. A triagem para HTLV-1/2 é obrigatória em bancos de sangue no país desde 1993, e a partir de 2014 é recomendada ao menos uma vez no acompanhamento de pacientes com HIV/aids, mas não em outras populações consideradas de risco para adquirir/transmitir esta infecção, como por exemplo, gestantes e pacientes com hepatites virais dos tipos B e C. Como o número de indivíduos em risco para adquirir/transmitir os HTLV a serem testados anualmente no Brasil é alto, qualquer estratégia que reduza o custo da triagem sorológica é necessária e bem vinda. O presente estudo avaliou o desempenho e o custo-minimização do uso de pool de soros na triagem sorológica de infecção por HTLV-1/2. Oitenta e uma amostras de soro sabidamente positivas para HTLV-1/2 foram retestadas utilizando dois ensaios imunoenzimáticos na triagem (EIA Murex HTLV I+II, Diasorin, e GOLD ELISA HTLV-1/2, REM) e dois testes confirmatórios [Western blot (WB), HTLV BLOT 2.4, MP Biomedicals e imunoensaio de linha (LIA), INNO-LIA HTLV I/II Score, Fujirebio], e separadas de acordo com os valores de DO/cut-off em: fortemente reagentes (DO/cut-off >12), e moderadamente reagentes (DO/cut-off >2,0 a 12,0). Posteriormente, estas amostras foram diluídas na razão dois em bolsa de plasma negativa para marcadores de banco de sangue até a perda de reatividade, e em seguida diluídas em diferentes pools de soros positivos e negativos para HIV, HBV e HCV, com vistas a determinar, respectivamente, a maior diluição de soro sem perda de sensibilidade e garantir a especificidade da reação. Subsequentemente, amostras com volume suficiente para ensaios de validação de métodos de diagnóstico segundo os parâmetros estabelecidos pelo Instituto Adolfo Lutz (P-SG-0022) foram selecionadas e testadas quanto à estratégia de pool de soros; 40 pools foram utilizados nos testes de acurácia e sete pools nos de precisão. Para o cálculo de redução de custo (custo-minimização), 2.000 amostras de soro/plasma de pacientes com hepatites virais B e C, e 625 amostras de plasma de pacientes com HIV/aids que haviam sido testadas individualmente e cujos resultados haviam sido publicados foram avaliadas em pool. Os resultados obtidos mostraram que o kit Murex foi mais sensível podendo ser diluído na razão 1:5 sem perda de sensibilidade e especificidade diagnóstica, com resultados de exatidão, precisão, sensibilidade, especificidade, valor preditivo positivo e negativo de 100% (coeficiente de correlação Kappa = 1). Em populações de risco, o uso da estratégia de pool de soros mostrou a mesma sensibilidade da análise individual, e uma redução de custo de 70,4% no grupo HBV, 60,7% no grupo HCV e 73,6% no grupo HIV/aids; estando o custo-minimização relacionado à prevalência da infecção nas populações de estudo: 1,9% (HBV), 4,0% (HCV), e 1,1% (HIV/aids). Concluindo, os resultados obtidos permitem sugerir a introdução da triagem sorológica para HTLV-1/2 utilizando pool de cinco soros e o kit Murex em inquéritos epidemiológicos, no acompanhamento de pacientes com outras infecções virais e possivelmente em gestantes no pré-natal. (AU)

The human T-cell lymphotropic viruses type 1 and type 2 (HTLV-1 and HTLV-2) are endemic in Brazil. HTLV-1/2 screening is mandatory in blood banks in the country since 1993, and from 2014 it is recommended at least once in the follow-up of patients with HIV/AIDS, but not in other populations considered at risk for acquiring/transmitting these infections, such as pregnant women and patients with viral hepatitis B and C. As the number of individuals at risk for acquiring/transmitting HTLV to be tested annually in Brazil is high, any strategy that reduces the cost of screening is necessary and welcomed. The present study evaluated the performance and costminimization of the use of pooling sera in serological screening for HTLV-1/2 infections. Eighty-one HTLV-1/2 truly positive serum samples were retested using two screening enzyme-linked immunoassays (EIA Murex HTLV I + II, Diasorin, and GOLD ELISA HTLV-1/2, REM) and two confirmatory assays [Western blot (WB), HTLV BLOT 2.4, MP Biomedicals and Line Immunoassay (LIA), INNO-LIA HTLV I / II Score, Fujirebio], and separated according to OD/cut-off values into: strongly reagents (OD/cut-off> 12), and moderately reagents (DO/ cut-off> 2.0 to 12.0). Subsequently, these samples were diluted at ratio two in serum from negative blood bag for infectious blood-borne diseases until the loss of reactivity to determine the highest serum dilution without loss of sensitivity, and next diluted in different pools of positive and negative HIV, HBV and HCV sera to ensure the specificity of the pooling strategy. Afterwards, samples with sufficient volume for diagnostic method validation assays according to the parameters established by the Adolfo Lutz Institute (P-SG-0022) were selected and tested for the pooling strategy: 40 pools for accuracy and 7 pools for precision analysis. For mostminimization calculation, 2,000 serum/plasma samples from patients with viral hepatitis B and C and 625 plasma samples from patients with HIV/AIDS that had been individually tested and the results had been published elsewhere were tested in pooling. The results obtained showed that the Murex kit was more sensitive and could be used at 1:5 dilution without loss of sensitivity. The accuracy, precision, sensitivity, specificity, and positive and negative predictive values were 100% (Kappa correlation coefficient = 1). In at-risk populations, the use of the serum pooling strategy reduced the cost of screening (cost-minimization) by 70.4% in the HBV, 60.7% in the HCV, and 73.6% in HIV/AIDS groups of patients, which depended on the prevalence of HTLV-1/2 in such populations: 1.9% (HBV), 4.0% (HCV), e 1.1% (HIV/aids). In conclusion, the results obtained suggest the introduction of HTLV-1/2 serological screening using pooling of five sera and the Murex kit in epidemiological surveys, in the follow-up of patients with other viral infections and possibly in prenatal screening programs. (AU)

Detection of Anti-Extractable Nuclear Antigens in Patients with Systemic Rheumatic Disease via Fluorescence Enzyme Immunoassay and Its Clinical Utility

FasciDIG. Diagnóstico oportuno y eficaz de fasciolosis humana / FasciDIG. Timely and effective diagnosis of human fasciolosis

El diagnóstico de fasciolosis humana, enfermedad zoonótica causada por el parásito Fasciola hepatica reúne los resultados de las técnicas: concentración por sedimentación (copa-cónica), FasciDIG en heces y FasciDIG en suero, además de los criterios clínico-epidemiológicos. FasciDIG constituye un ensayo inmunoenzimático que detecta antígenos de excreción-secreción de F. hepatica a partir de muestra de suero y heces. Permite diagnosticar la infección en cada una de las formas clínicas de la enfermedad y presenta una sensibilidad diagnóstica superior a las técnicas convencionales que detectan huevos del parásito (copa-cónica), por lo que se consideró oportuno abordar algunos conceptos relacionados con esta técnica inmunodiagnóstica y analizar su aplicabilidad para el diagnóstico oportuno y eficaz de esta parasitosis(AU)

Diagnosis of human fasciolosis, a zoonotic disease caused by the parasite Fasciola hepatica, combines the results of the following techniques: conical cup, feces FasciDIG and serum FasciDIG, as well as clinical-epidemiological criteria. FasciDIG is an enzyme immunoassay that detects F. hepatica excretion / secretion antigens in serum and feces samples. It makes it possible to diagnose infection at each of the clinical stages of the disease with a higher diagnostic sensitivity than conical cup. Therefore, it was considered appropriate to address a number of concepts regarding this immunodiagnostic technique and analyze its applicability in the timely and effective diagnosis of this helminth infection(AU)

Performance of Hepatitis B Core-Related Antigen Versus Hepatitis B Surface Antigen and Hepatitis B Virus DNA in Predicting HBeAg-positive and HBeAg-negative Chronic Hepatitis

BACKGROUND: We examined changes in hepatitis B core-related antigen (HBcrAg) during the four sequential phases of chronic hepatitis B virus (HBV) infection: hepatitis B e antigen (HBeAg)-positive chronic infection (EPCI) and hepatitis (EPCH), followed by HBeAg-negative chronic infection (ENCI) and hepatitis (ENCH). We compared the performance of serum HBcrAg, hepatitis B surface antigen (HBsAg), and HBV DNA in predicting EPCH and ENCH. METHODS: We enrolled 492 consecutive patients: 49 with EPCI, 243 with EPCH, 101 with ENCI, and 99 with ENCH. HBcrAg was detected by chemiluminescent enzyme immunoassays. HBsAg and HBeAg were detected by chemiluminescent microparticle immunoassays. HBV DNA was detected by real-time PCR. Predictive performance of HBcrAg, HBsAg, and HBV DNA was evaluated using ROC curves. RESULTS: Areas under ROC curves (AUCs) of HBcrAg, HBsAg, and HBV DNA for predicting EPCH were 0.738, 0.812, and 0.717, respectively; optimal cutoffs were ≤1.43×105 kU/mL, ≤1.89×104 IU/mL, and ≤3.97×107 IU/mL, with sensitivities and specificities of 66.3% and 77.6%, 65.0% and 93.9%, and 60.5% and 79.6%, respectively. AUCs of HBcrAg, HBsAg, and HBV DNA for predicting ENCH were 0.887, 0.581, and 0.978, respectively; optimal cutoffs were >26.8 kU/mL, >2.29×102 IU/mL, and >8.75×103 IU/mL, with sensitivities and specificities of 72.7% and 95.1%, 86.9% and 39.6%, and 89.9% and 92.1%, respectively. CONCLUSIONS: HBsAg and HBV DNA were the best predictors of EPCH and ENCH, respectively. HBcrAg is an important surrogate marker for predicting EPCH and ENCH.

Neopterin Levels and Indoleamine 2,3-Dioxygenase Activity as Biomarkers of Immune System Activation and Childhood Allergic Diseases

BACKGROUND: Although Th2 immune activation is predominant in allergic diseases, neopterinlevels and indoleamine 2,3-dioxygenase (IDO)-1 activity (kynurenine:tryptophan ratio), which reflect Th1 immune activity, increase with interferon-gamma (IFN-γ) stimulation. We investigated neopterin, tryptophan, and kynurenine levels as biomarkersof the Th1 immune system activation and changes in IDO-1 activityin children with asthma, allergic rhinitis, and atopic dermatitis, as well as the relationship between these biomarkers and the total IgE level, age, and disease severity. METHODS: We divided 205 children (80 girls and 125 boys, four months to 17 years old) into four groups: controls, patients with asthma, patients with allergic rhinitis, and patients with atopic dermatitis. Peripheral venous blood samples were collected. Neopterin levels were determined by an enzyme immunoassay. Tryptophan and kynurenine levels were analyzed using HPLC. IDO-1 enzyme activity was calculated using tryptophan and kynurenine levels. IgE levels were measured. The Mann-Whitney U test, Kruskal-Wallis test, and Conover post-hoc method were used for statistical analysis. RESULTS: Neopterin, tryptophan, and kynurenine levels were higher and IgE levels and IDO-1 enzyme activity were lower in patients with asthma and allergic rhinitis than in controls (P < 0.05). Patients with atopic dermatitis showed higher neopterin, tryptophan, and kynurenine levels, higher IDO-1 activity, and lower IgE levels thancontrols (P < 0.05). CONCLUSIONS: The Th1/Th2 balance is disrupted in children with allergic diseases, concomitant with increased Th1-mediated immune response activation and reduced IgEproduction, which is promoted by Th2-type cytokines.

Laboratory Diagnosis of Clostridium difficile Infection in Korea: The First National Survey

In May 2015, we conducted a voluntary online survey on laboratory diagnostic assays for Clostridium difficile infection (CDI) across clinical microbiology laboratories in Korea. Responses were obtained from 66 laboratories, including 61 hospitals and five commercial laboratories. Among them, nine laboratories reported having not conducted CDI assays. The toxin AB enzyme immunoassay (toxin AB EIA), nucleic acid amplification test (NAAT), and C. difficile culture, alone or in combination with other assays, were used in 51 (89.5%), 37 (64.9%), and 37 (64.9%) of the remaining 57 laboratories, respectively, and 23 (40.4%) of the laboratories performed all three assays. Only one laboratory used the glutamate dehydrogenase assay. Nine laboratories used the toxin AB EIA as a stand-alone assay. The median (range) of examined specimens in one month for the toxin AB EIA, NAAT, and C. difficile culture was 160 (50–2,060), 70 (7–720), and 130 (9–750), respectively. These findings serve as valuable basic data regarding the current status of laboratory diagnosis of CDI in Korea, offering guidance for improved implementation.

Nkx-2.5 Regulates MDR1 Expression via Its Upstream Promoter in Breast Cancer Cells

BACKGROUND: Increased expression of MDR1 gene is one of the major mechanisms responsible for multidrug resistance in cancer cells. Two alternative promoters, upstream and downstream, are responsible for transcription of MDR1 gene in the human. However, the molecular mechanism regarding the transactivation of MDR1 upstream promoter (USP) has not been determined. METHODS: Dual-luciferase reporter gene assays were used to assess the effect of Nkx-2.5 on MDR1 USP activity using reporter plasmids for human MDR1 USP and its mutants. MDR1 mRNA level was examined by quantitative real-time PCR. The direct binding of Nkx-2.5 to the USP of MDR1 was evaluated by promoter enzyme immunoassays and chromatin immunoprecipitation assays.

Performance Evaluation of Two Immunochromatographic Assays for Rotavirus Detection in Stool Specimens

BACKGROUND: Rotavirus is a major pathogen causing enteritis worldwide in children under five years of age. In recent years, immunochromatographic assay (ICA) has been widely used as a diagnostic test for rotavirus detection. This study aimed to compare and evaluate the performance of ICA-based rotavirus rapid test kits from two manufacturers. METHODS: Residual stool samples from a total of 130 children with acute enterocolitis from November 2017 to January 2018 were used. We compared the results of the two immunochromatographic methods (SD BIOLINE Rotavirus kit and GENEDIA Rotavirus Ag Rapid Test) with those of the currently used enzyme immunoassay method. RESULTS: Positive agreement, negative agreement, and total agreement rates between the SD BIOLINE rotavirus kit and the enzyme immunoassay were 98.0%, 100%, and 99.2%, respectively. Positive agreement, negative agreement, and total agreement rates between the GENEDIA Rotavirus Ag Rapid Test and the enzyme immunoassay were 96.0%, 100%, and 98.4%, respectively. CONCLUSIONS: Both rotavirus rapid test kits showed very good agreement with the conventional enzyme immunoassay. Therefore, it could be a useful test to detect rotavirus directly from stool samples in a short time.

Inhibitory Effects of Protopanaxadiol on Lipopolysaccharide-Induced Reactive Oxygen Species Production and MUC5AC Expression in Human Airway Epithelial Cells / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: MUC5AC is one of the major secretory mucin genes in the human airway epithelium. MUC5AC expression is increased by a variety of inflammatory mediators. Protopanaxadiol (PPD), one of the major active metabolites in ginseng, is known to have anti-inflammatory, antitumor and antioxidant properties. However, the effects of PPD on mucin secretion of airway epithelial cells still have not been reported. Therefore, the aim of this study is to investigate the effect of PPD on lipopolysaccharide (LPS)-induced MUC5AC expression in human airway epithelial cells. MATERIALS AND METHOD: In the mucin-producing human NCI-H292 airway epithelial cells, the effect of PPD on MUC5AC expression was investigated using reverse transcription-polymerase chain reaction and enzyme immunoassay after treated with LPS. N-acetylcysteine (NAC) as a reactive oxygen species (ROS) scavenger, and apocynin as a nicotinamide adenine dinucleotide phosphate oxidase inhibitor were used to compare the inhibitory effect of PPD on LPS-induced ROS production in human NCI-H292 cells. RESULTS: LPS significantly increased MUC5AC mRNA expression and protein production. LPS also increased ROS production. PPD inhibited LPS-induced MUC5AC mRNA expression and protein production as well as ROS production. In addition, NAC and apocynin inhibited LPS-induced MUC5AC mRNA expression and protein production. CONCLUSION: These results demonstrate that PPD inhibits LPS-induced MUC5AC expression via ROS in human airway epithelial cells and the inhibitory effect of PPD was similar to that of NAC and apocynin. These findings indicate that PPD may be a therapeutic agent for control of mucus secretion and oxidative stress in human airway epithelial cells.

Endoplasmic Reticulum Stress Induces MUC5AC and MUC5B Expression in Human Nasal Airway Epithelial Cells

OBJECTIVES: Endoplasmic reticulum (ER) stress is known to be associated with inflammatory airway diseases, and three major transmembrane receptors: double-stranded RNA-activated protein kinase-like ER kinase, inositol requiring enzyme 1, and activating transcription factor 6 (ATF6) play important roles in ER stress-related proinflammatory signaling. However, the effects of ER stress and these three major signaling pathways on the regulation of the production of airway mucins in human nasal airway epithelial cells have not been elucidated. METHODS: In primary human nasal epithelial cells, the effect of tunicamycin (an ER stress inducer) and 4-phenylbutyric acid (4-PBA, ER stress inhibitor) on the expression of MUC5AC and MUC5B was investigated by reverse transcriptasepolymerase chain reaction, real-time polymerase chain reaction, enzyme immunoassay, and immunoblot analysis. Small interfering RNA (siRNA) transfection was used to identify the mechanisms involved. RESULTS: Tunicamycin increased the expressions of MUC5AC and MUC5B and the mRNA expressions of ER stress-related signaling molecules, including spliced X-box binding protein 1 (XBP-1), transcription factor CCAAT-enhancer-binding protein homologous protein (CHOP), and ATF6. In addition, 4-PBA attenuated the tunicamycin-induced expressions of MUC5AC and MUC5B and the mRNA expressions of ER stress-related signaling molecules. Furthermore, siRNA knockdowns of XBP-1, CHOP, and ATF6 blocked the tunicamycin-induced mRNA expressions and glycoprotein productions of MUC5AC and MUC5B. CONCLUSION.: These results demonstrate that ER stress plays an important role in the regulation of MUC5AC and MUC5B via the activations of XBP-1, CHOP, and ATF6 in human nasal airway epithelial cells.