Serological response to Neospora caninum infection in goats and agreement between three diagnostic techniques to detect caprine neosporosis / Resposta sorológica à infecção por Neospora caninum em cabras e concordância entre três técnicas diagnósticas para detecção de neosporose caprina

The present study aimed to measure the serological response of goats infected with Neospora caninum by assessing the diagnostic performance and agreement between three techniques (indirect immunofluorescent antibody test, IFAT; Neospora agglutitation test, NAT; enzyme-linked immunosorbent assay, ELISA). The panel of sera were comprised of 500 samples of goats, and 60 reference serum samples. These reference and field serum samples were tested by ELISA, NAT, and IFAT. In the field serum samples tested, the seroprevalences of anti-N. caninum antibodies were 3.2%, 4.6%, and 6.4% in the NAT, IFAT and ELISA, respectively. Using the IFAT as the gold standard, the NAT and the ELISA agreement was considered weak (k=0.28) and strong (k=0.75), respectively. When the IFAT performance was used for comparison purposes, the ELISA showed 91.3% sensitivity and 97.7%, specificity with a PPV of 65.2% and a NPV of 99.6%; The NAT presented sensitivity of 26.1% and specificity of 97.9% with a PPV of 37.5% and a NPV of 96.5%. Accordingly, the IFAT should remain the assay of choice for studies about N. caninum infection in goats in individual serum samples. A combination of serological assays with high sensitivity and specificity is recommended in serosurveys of caprine neosporosis.(AU)

Objetivou-se avaliar a resposta sorológica de caprinos infectados com Neospora caninum mediante o estudo da performance e concordância de três técnicas sorológicas (RIFI, NAT e ELISA). O painel de soros testes foi composto por 500 amostras de caprinos e ainda 60 soros classificados como de referência. Todos os soros de referência e de campo foram testados por ELISA, NAT e RIFI. Nos soros de campo, as soroprevalências de anticorpos anti-N. caninum foram de 3,2% no NAT, 4,6% na RIFI e 6,4% no ELISA. Utilizando a RIFI como técnica de referência, a concordância de NAT e ELISA foi considerada fraca (k=0,28) e substancial (k=0,75), respectivamente. Ainda utilizando a RIFI como comparação, foram obtidos valores de sensibilidade de 91,3% e 97,7% de especificidade no ELISA, e valores preditivos positivo de 65,2% e negativo de 99,6%; NAT apresentou resultados de sensibilidade de 26,1% e de especificidade de 97,9% com valores preditivos positivo de 37,5% e negativo de 96,5%. Com base nos resultados deste trabalho, sugerimos que a RIFI permaneça como técnica de escolha no estudo da neosporose caprina em amostras individuais, resguardando as recomendações e pontos de corte adotados neste estudo. Indicamos a associação de técnicas sorológicas de alta sensibilidade e especificidade.(AU)

The value of non-invasive prenatal genetic testing as first-trimester screening / 中华检验医学杂志

Objective To evaluate the value of non-invasive prenatal testing (NIPT) as first-trimester screen (FTS) for the detection of trisomies 21, 18 and 13. Methods This was a retrospective study. 8517 pregnancies who performed NIPT at Obstetrics and Gynecology Hospital of Fudan University from 2017 May to 2018 June. 14 cases (0.16％) were failed. 8503 pregnancies were divided into 2 groups:NIPT joint traditional screening, NIPT. High risk pregnancies were verified by prenatal diagnosis. Evaluate the performance of NIPT. All pregnancies were followed up. Frequencies were compared with Fisher′s exact test. Results 8517 pregnancies underwent NIPT. 14 cases (0.16％) were failed. 83 cases of remaining 8503 cases had high risk results, among which 29 were trisomy 21, 14 were trisomy 18, 6 were trisomy 13 and 34 were sex chromosome aneuploidies (SCA). In 2996 cases who underwent NIPT joint traditional screening, NIPT found 14 cases of common aneuploidies 12 cases of SCA. 11 and 3 cases were validated by invasive prenatal diagnosis, respectively. In 5507 NIPT cases, 35 cases of common aneuploidies and 22 cases of SCA were found, among which 29 and 11 cases were validated. There was no significant differences between two groups for common aneuploidies (P=1.00). The sensitivity were 11/11 and 29/29 respectively,the specificity were 99.90％(2982/2985) and 99.89％(5472/5478), the positive predictive value (PPV) were 78.57％(11/14) and 82.86％(29/35), the negative predictive value (NPV) were 100％(2982/2982) and 100％ (5472/5472), respectively. Besides, the sensitivity and PPV of NIPT for SCA were 100％ and 41.18％. No false negative was found. Conclusions The proportion of pregnancies underwent NIPT alone was 64.77％. NIPT had excellent performance (the specificity and PPV) for common aneuploidies, and also had a certain value for SCA, which greatly reduced in invasive diagnosis. NIPT is a commendable essay as a first-line prenatal screening. Invasive diagnosis is still necessary for pregnancies with high-risk of NIPT.

The value of plasma fetal free DNA in the screening of Down syndrome in pregnant women of advanced maternal age / 国际检验医学杂志

Objective To investigate the value of plasma fetal free DNA in the screening of Down syndrome in pregnant women of advanced maternal age .Methods 298 cases of pregnant women of advanced maternal age in our hospital from February 2012 to May 2014 were chosen as the research object ,who experienced prenatal serological screening and fetal free DNA detection by high-throughput gene sequencing technology .According to the karyotype analysis of amniotic fluid/umbilical cord blood puncture ,we compared the detection efficiency of traditional serological screening and high-throughput noninvasive DNA detection for prenatal Down's syndrome screening in pregnant women of advanced maternal age ,and evaluated their sensitivity and specificity .Results 26 cases of high risk pregnant women were screened by using serological methods (positive rate was 8 .7% ) .Among them ,we found 20 cases of high risk pregnant women with Down syndrome (21-trisomy) (Tang screening positive rate was 6 .7% ) ,and 5 cases of 18-trisomy syndrome (1 .7% ) and 2 cases of 13-trisomy syndrome(0 .7% ) .9 cases of high risk pregnant women (positive rate was 8 .7% ) was detected with noninvasive DNA technology ,all within the range of serological screening results (positive rate was 3% ) .Among them ,there were 6 cases of high risk 21-trisomy (positive rate was 2% ) ,and 3 cases of high risk 18-trisomy (1% ) . High risk pregnant women were further verified by amniotic fluid/umbilical cord blood cell karyotype analysis .The results showed that there were 5 cases of 21-trisomy positive(1 .7% ) ,2 cases of 18-trisomy positive(0 .7% ) ,and 2 cases were normal(0 .7% ) .The sensitivity ,specificity and accuracy of serological screening were 100% ,93 .3% and 94 .9% respectively .The sensitivity ,specificity and accuracy of noninvasive DNA detection were 100% ,97 .9% and 99 .6% respectively .There were statistically significant differ-ences on the total positive rate ,Tang screen positive rate ,Tang screening false positive rate ,specificity and positive predictive value between the two methods (P<0 .05) .Conclusion Analysis of cffDNA using noninvasive DNA detection technique has a high sen-sitivity ,specificity and accuracy for DS screening in elderly patients ,and deserves clinical promotion .

Problemas de salud en individuos que acuden a donar sangre en Cienfuegos / Health problems in individuals attending in Cienfuegos to donate blood

Introducción: a través de la selección médica predonación y la pesquisa de infecciones postdonación se reconocen enfermedades ocultas o en sus estadios asintomáticos iniciales, sus factores de riesgos o ambos. Objetivos: determinarlos principales problemas de salud en donantes de sangre de Cienfuegos. Métodos: estudio observacional descriptivo de corte transversal retrospectivocon los individuos que acudieron a donar sangre total en la provincia de Cienfuegos desde 2010 hasta 2014.Las unidades de análisis fueron los donantes identificados como no aptos para donar sangre y aquellos con resultados positivos en las pruebas de tamizaje postdonación. Resultados: la décima parte de los individuos presentaron algún problema o desviación de la salud presente o potencial. Las principales causas vinculadas al rechazo del donante fueron: el aspecto turbio del plasma, alteraciones en las cifras de tensión arterial, concentración de hemoglobina fuera de los valores aceptados, enfermedades infecciosas o sus factores de riesgos, el uso de medicamentos y otras condiciones médicas. Además, entre los individuos que donaron hubo una proporción pequeña que presentaron resultados positivos / reactivos a las pruebas infecciosas, en lo fundamental para anticuerpos contra la hepatitis C. Conclusiones: aunque los hallazgos de este estudio son consistentes con la mayoría de otros autores, la presencia de desviaciones de la salud en una población supuestamente sana resulta significativa. Futuras investigaciones deberían centrarse en esta temática, puntualizando en el componente educativo, las políticas y los procedimientos de selección, consejería y seguimiento clínico-epidemiológico de donantes de sangre, entre otras(AU)

Introduction: Through medical selection and pre-donation screening for hidden infections post-donation illness or asymptomatic in its early stages, its risk factors or both are recognized. Aims: Identify the main health problems in Cienfuegos blood donors. Methods: A descriptive cross section study with all individuals who came to donate whole blood in the province of Cienfuegos from 2010 to 2014 was performed. The analysis units were the donors identified as ineligible to donate blood and those with positive results in screening tests post-donation. Results: Tenth of the individuals had a problem or deviation from present or potential health. The main causes linked to rejection of the donor were: the cloudy appearance of plasma, alterations in blood pressure levels, hemoglobin concentration outside the accepted values, infectious diseases or risk factors, use of medicines and other medical conditions . Also among individuals who donated there was a small proportion had positive / reactive to infectious test results, fundamentally for antibodies to hepatitis C. Conclusions. Although the findings of this study are consistent with most other authors, the presence of deviations from health in a supposedly healthy population is significant. Future research should focus on this subject, pointing in the educational component, policies and selection procedures, counseling and clinical and epidemiological monitoring of blood donors, among others(AU)

Perfil de inaptidão na triagem clínica e sorológica de candidatos à doação de sangue / Profile of inability in the clinic and serological screening of candidates for blood donation

Objetivo: Caracterizar os candidatos quanto ao gênero e analisar a prevalência dos critérios de inaptidão adotados às doações de sangue, realizadas no Banco de Sangue Santa Maria, em Santa Maria, RS. Métodos: Dados retrospectivos arquivados foram avaliados, analisando-se os critérios de exclusão na triagem clínica e sorológica, no período de janeiro de 2005 até dezembro de 2010. Foram analisados 20.264 doadores. O estudo foi aprovado pelo Comitê de Ética e Pesquisa da Universidade Federal do Rio Grande do Sul-UFRGS, sob número de protocolo 18147. Resultados: Novecentos e setenta e seis (5%) candidatos foram considerados inaptos pela triagem clínica e 19.288 (95%) foram considerados aptos para prosseguirem com os testes laboratoriais. Dos doadores aptos, 941 (5%) foram excluídos na triagem sorológica, totalizando 18.347 bolsas de sangue disponíveis para uso. Predominaram os doadores do sexo masculino (62%) e a principal causa de exclusão, na triagem clínica, foi hipertensão (0,7%). Para a triagem sorológica, a principal causa de exclusão foi a Doença de Chagas (1,5%). Conclusão: Ressaltou-se a importância da triagem clínica, tendo em vista que ela excluiu 5% dos candidatos à doação e a relevância da triagem sorológica ser feita corretamente, evitando que resultados falso-negativos sejam liberados.

Objective: Characterize donors by gender and analyze theprevalence of the inability criteria of donations made at the SantaMaria Blood Bank, located at Santa Maria, Brazil. Methods: First,we searched historical data for exclusion criteria used in clinicaland serological screenings during the period from January, 2005 toJuly, 2010. We evaluated 20,264 blood donors' data for this study.The Ethical Committee of Rio Grande do Sul Federal UniversityUFRGSapproved this study under the protocol number 18147.Results: Nine hundred and seventy-six (5%) candidates wereconsidered unfit by the clinical screening and 19,288 (95%) wereconsidered fit. From the resulting fit population of the clinicalscreening, 941 (5%) were excluded from donating by the serologicalscreening, totaling 18.347 blood donations fit for use. The resultsshows that majority of the donors were male (62%) and the leadingcause of exclusion from donating in the clinical screening washypertension (0.7%). As for the serological screening, the leadingcause for exclusion was Chagas disease (1.5%). Conclusion: Thestudy stress the importance of the clinical screening process, giventhat it excluded 5% of blood donations, which were unfit for use. Wealso notice the relevance of a correctly done serological screening,thus avoiding that false-negative results are released.

Prevalência de infecção chagásica em doadores de sangue no estado de Pernambuco, Brasil / The prevalence of chagasic infection among blood donors in the State of Pernambuco, Brazil

A doença de Chagas é uma infecção sistêmica de evolução crônica cujo agente etiológico é o parasita Trypanosoma cruzi. O último relato encontrado sobre a soroprevalência da doença em doadores de sangue realizado na capital pernambucana, Recife, data de 1970, onde foi encontrada uma prevalência de 4,4 por cento em doadores de um hospital local. Devido à falta de informações divulgadas sobre a infecção por T. cruzi e sendo Pernambuco uma região endêmica para esta enfermidade, o presente estudo se propôs a analisar o perfil dos doadores de sangue do Hemocentro de Pernambuco (Hemope), que apresentaram reatividade para doença de Chagas, no período de 2002 a 2007. O perfil dos doadores inaptos foi avaliado de acordo com gênero, idade e procedência segundo as mesorregiões de Pernambuco. Foi encontrada uma prevalência de 0,17 por cento para doença de Chagas e 6,89 por cento das bolsas descartadas deveram-se a essa reatividade. Em relação ao gênero dos doadores, foi significativamente maior a contribuição dos homens (p<0,0001). A faixa etária de 18-30 anos apresentou menor quantidade de sorologias reativas (20,21 por cento). Foi verificado também que, na Região Metropolitana do Recife, a quantidade de reações inconclusivas foi estatisticamente maior que a quantidade de sorologias reagentes (p=0,0440). Desta forma, estudos epidemiológicos fornecem dados importantes no sentido de se avaliar diretamente o risco de transmissão de uma doença por transfusão sanguínea e permitem que também em regiões endêmicas se avalie a eficácia das medidas para o controle vetorial.

Chagas disease is a systemic infection with a chronic onset transmitted by Trypanosoma cruzi. The last study conducted in Recife, capital of Pernambuco state, was carried out during 1970. At that time a prevalence of 4.4 percent was found among blood donors of a local hospital. Due to the lack of epidemiology data on T. cruzi infection and as Pernambuco is an endemic region, the present study describes the profile of blood donors who presented reactivity for Chagas disease during the period of 2002 to 2007 in the state's blood bank (Hemope). The profile of unsuitable donors was evaluated according to gender, age and according to the meso-regions of Pernambuco. A prevalence of 0.17 percent was found for Chagas disease, whereas 6.89 percent of the rejected blood bags were due to this reactivity. As far as gender is concerned, the reactivity of men was higher than that of women (p<0.0001). Additionally, the age group between 18-30 years was less infected (20.21 percent). On analyzing the reactivity in each one of the meso-regions of the state, it was found that, in the Metropolitan Region of Recife, the number of inconclusive reaction cases was statistically higher than the number of reactive serology cases (p=0.0440). Thus, epidemiological studies provide important data to indirectly evaluate the risk of blood-borne diseases and allow indirect evaluation of the effectiveness of vectorial control measures in endemic regions.

Epidemiological profile of hepatitis C in blood donors at the Uberaba Regional Blood Center / Perfil epidemiológico para hepatite C em doadores de sangue do Hemocentro Regional de Uberaba

The aim of the present study was to outline the serological profile of hepatitis C among blood donors seen at the Uberaba Regional Blood Center, Hemominas Foundation, over the last 14 years. The frequency of hepatitis C was compared between first-time and repeat donors and the epidemiological characteristics of those with positive and indeterminate ELISA anti-HCV (third and fourth generation) were analyzed based on the donor histories kept in the archives of the Uberaba Regional Blood Center. The serological ineligibility rate was 0.3 percent, with higher prevalence in the group of first-time donors. We did not find any significant differences regarding age, skin color, marital status or place of residence between eligible and ineligible donors; however, the frequency of positive serology was higher among men. The lower (0.3 percent) rate of ineligibility due to hepatitis C that was observed at the Uberaba Regional Blood Center, in relation to most Brazilian blood centers, is probably due to the large number of repeat donors (83.3 percent). This reinforces the importance of achieving donor commitment for increasing transfusion safety.

O objetivo deste estudo foi traçar o perfil sorológico para a hepatite C nos doadores de sangue do Hemocentro Regional de Uberaba/Fundação Hemominas nos últimos 14 anos, comparando a sua ocorrência em doadores iniciais e de retorno e analisando as características epidemiológicas daqueles com ELISA anti-HCV (terceira e quarta geração) positivo e indeterminado, a partir dos históricos dos doadores nos arquivos do Hemocentro Regional de Uberaba. A inaptidão sorológica encontrada foi de 0,3 por cento, com maior ocorrência no grupo de doadores iniciais. Não encontramos diferenças significativas quanto à idade, cor da pele, estado civil e local de residência entre os aptos e os inaptos, porém a ocorrência de sorologia positiva foi maior nos homens. A menor prevalência de inaptidão para hepatite C (0,3 por cento) no Hemocentro Regional de Uberaba, em relação à maioria dos hemocentros do país, é provavelmente devido ao grande (83,3 por cento) número de doadores de repetição, reforçando assim a importância da fidelização do doador para o aumento da segurança transfusional.

Anti-Trypanosoma cruzi antibody detection in blood donors in the Southern Brazil

Trypanosoma cruzi, the causal agent of Chagas' Disease, is a widely spread protozoa in America. Blood transfusion is the secondly most important way of acquiring the infection. In blood banks, tests are performed to eliminate potentially infected blood. This study aimed to evaluate the positivity for T. cruzi in blood samples of donor's candidates in Southern Brazil. The study was based on a sampling containing all blood donors of Hemopel - a Pelotas City Blood Center, Rio Grande do Sul State, Brazil, from 2004 to 2005. Serological study was performed using ELISA Chagatest. Sampling containing values ± 20 percent cut off were evaluated using ELISA Chagatek, ELISA Alka/Adaltis, IHA Chagatest and IIF Imunocruzi. TESA-Blot was used as a confirmatory procedure in situations where blood samples showed conflicting results. From 4,482 samples collected in 2004 and 2005, the reactivity for anti-T. cruzi was 0.96 percent (43). Among those, 21 cases (0.47 percent) were confirmed as positive - most of them were female, with low school level and averaging 47.2 percent years old. Interestingly, the blood donors are not aware of being contaminated and this fact makes it difficult for controlling the disease. Chagas' Disease was one of the main reasons for discarding blood bags through serological control in Southern Brazil. Sampling reactivity showed variation among the different techniques used for anti-T. cruzi research. In order to obtaining more secure and conclusive results, more than one diagnostic technique must be used.

Importância dos testes sorológicos de triagem e confirmatórios na detecção de doadores de sangue infectados pelo vírus da hepatite C / Importance of screening and confirmatory tests to detect blood donors infected by the hepatitis C virus

A triagem sorológica de doadores de sangue com baixos índices de prevalência de infecção, como no caso da hepatite C (HCV), gera um percentual considerável de resultados falso-positivos e descarte de bolsas de hemocomponentes freqüentemente não infectados. O objetivo deste estudo foi pesquisar o perfil sorológico e, com base no teste confirmatório, a ocorrência de hepatite C nos doadores com sorologia positiva ou indeterminada do Hemocentro Regional de Uberaba (HRU). Os testes confirmatórios foram realizados por meio da detecção do RNA do HCV no plasma, utilizando-se o método RT-PCR qualitativa. Foram realizadas, no período de 1992 a 2005, 171.027 doações de sangue no HRU, sendo 24,3 por cento de doadores iniciais e 75,7 por cento de retorno. O índice de inaptidão para HCV foi de 0,3 por cento (561 doações), sendo que 53,0 por cento destas eram de doadores iniciais e 47,0 por cento de retorno, com prevalências de 0,5 por cento e 0,2 por cento, respectivamente (p<0,0001). O índice de reações inconclusivas foi significativamente maior nos doadores de retorno (p=0,0214). Noventa e oito candidatos foram submetidos à PCR qualitativa e apenas 34 (34,7 por cento) apresentaram resultados positivos, com índice de positividade significativamente menor nos doadores de retorno (p=0,0184) e quase três vezes menor nos inconclusivos. Assim, verificamos que grande número de doadores, tanto anti-HCV positivos quanto indeterminados, não tiveram confirmada a presença da infecção pelo HCV, levando-nos a concluir que a inaptidão sorológica para hepatite C no HRU, na maioria das vezes, não correspondeu à presença de infecção viral no doador.

Serological screening of blood donors with low indexes of infection, including hepatitis C virus (HCV), accounts for a substantial percentage of false-positive results with consequent loss of non-infected blood components. The aim of this study was to evaluate the occurrence of hepatitis C using confirmatory tests for blood donors with positive or inconclusive results at Hemocentro Regional de Uberaba (HRU). Confirmatory tests were performed by the detection of HCV RNA in plasma using qualitative RT-PCR. The study was carried out from 1992 to 2005 for 171,027 blood donors, 24.3 percent first-time and 75.7 percent repeat donors. The ineligibility rate to HCV was 0.3 percent (561 donors) with 52.9 percent of them being first-time donors and 47.0 percent repeat donors with prevalences of 0.5 percent and 0.2 percent respectively (p<0.0001). The rate of inconclusive results was significantly higher among repeat donors (p=0.0214). Ninety-eight samples were subjected to qualitative PCR and only 34.7 percent (34) had positive results, with a significantly lower rate of positiveness for repeat donors (p = 0.0184) and almost a threefold lower rate of inconclusive results for the same donors. These results showed that, for a large number of donors with positive and inconclusive tests for anti-HCV, the infection was not confirmed. We concluded that serological ineligibility for hepatitis C of donors at HRU was not always associated with the presence of viral infection.