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Pesqui. vet. bras ; 38(1): 143-146, Jan. 2018. tab, ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-895551


Leptospirosis is a worldwide zoonosis, affecting humans, domestic and wild animals. The present study aimed to evaluate prevalence of anti-Leptospira spp. antibodies in Barbary sheep at the Curitiba zoo. Microscopic agglutination test (MAT) was performed using 17 serogroups. Antibodies against Leptospira spp. were observed in 23.5% samples and Icterohaemorrhagiae was the only prevalent serogroup. The presence of anti-Leptospira antibodies in Barbary sheep indicates exposure to leptospires; thus monitoring and preventive measures are necessary in zoo's captive animals, since they can act as sentinels of environmental exposure in an area with high movement of people.(AU)

A leptospirose é uma zoonose mundial que afeta seres humanos, animais domésticos e selvagens. O presente estudo objetivou avaliar a prevalência de anticorpos anti-Leptospira spp. em aoudads do zoológico de Curitiba. Foi realizado o teste de Soroaglutinação microscópica (SAM) utilizando 17 sorogrupos. Anticorpos contra Leptospira spp. foram observados em 23.5% das amostras de aoudads e Icterohaemorrhagiae foi o único sorogrupo prevalente. A presença de anticorpos em aoudads indica exposição a leptospiras portanto monitoramento e medidas preventivas são necessários em animais confinados em zoológicos, uma vez eles podem atuar como sentinelas de exposição ambiental em uma área com alta circulação de pessoas.(AU)

Animais , Anticorpos Antivirais/análise , Leptospirose/epidemiologia , Ruminantes/imunologia , Animais de Zoológico/imunologia , Testes Sorológicos/veterinária
Mem. Inst. Oswaldo Cruz ; 113(8): e170433, 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-955113


BACKGROUND The diagnosis of dengue is complex. Until recently, only specialised laboratories were able to confirm dengue infection. However, this has changed with the newly available immunochromatographic rapid tests. Early diagnosis is of great interest, and point-of-care rapid tests have been increasingly used in Brazil. Most of those tests have not undergone validation in the Brazilian population. In this context, we decided to evaluate a rapid test introduced in the Federal District (FD). OBJECTIVES To estimate the accuracy and reliability of the SD Bioeasy Dengue Duo rapid test and its components to detect dengue infections in a consecutive sample of symptomatic residents in the FD, Brazil. METHODS In total, 1353 venous blood samples were collected between 2013 and 2014. Two hundred and six positive samples (cases) and 246 negative samples (non cases) were required for sensitivity and specificity estimation, respectively; for agreement evaluation, we used 401 samples. The reference standard used was a composite of MAC-ELISA, virus isolation and real-time polymerase chain reaction (RT-qPCR). The evaluation was conducted prospectively under field conditions in the public health units of the FD. FINDINGS The results for the overall accuracy of the rapid test (NS1/IgM combined) showed 76% sensitivity and 98% specificity. The sensitivity for the NS1 component (67%) was better than that for the IgM component (35%). The positive likelihood ratio was 46, and the negative likelihood ratio was 0.24. The reliability of the test (NS1/IgM combined) demonstrated crude agreement of 98% (Kappa index 0.94). MAIN CONCLUSIONS The present phase III, large-scale validation study demonstrates that the rapid test SD Bioeasy Dengue Duo has moderate sensitivity (NS1/IgM combined) and high specificity. Therefore, the test is useful in confirming the diagnosis of dengue, but not enough to rule out the diagnosis. Our results also suggest that Dengue virus (DENV) viral load estimated through the RT-qPCR and antibody level measured through the MAC-ELISA could have had a direct influence on the accuracy of the rapid test.

Humanos , Imunoglobulina M/análise , Dengue/diagnóstico , Diagnóstico Precoce , Brasil/epidemiologia , Chile/epidemiologia , Reação em Cadeia da Polimerase em Tempo Real , Anticorpos Antivirais/sangue
Braz. j. microbiol ; 49(supl.1): 68-75, 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-974318


Abstract Serological testing and culling infected animals are key management practices aiming eradication of bovine leukemia virus infection. Here, we report the development of an indirect ELISA based on BLV recombinant capsid protein (BLVp24r) to detect anti-BLV antibodies in cattle serum. The BLVp24r was expressed in Escherichia coli and purified by affinity chromatography, and then used to set up the ELISA parameters. The Polysorp ® plate coated with 50 ng of antigen/well and bovine serum diluted 1:100 gave the best results during standardization. Using sera from infected and non-infected cattle we set up the cutoff point at 0.320 (OD450 nm) with a sensitivity of 98.5% and specificity of 100.0%. Then, we tested 1.187 serum samples from dairy (736 samples) and beef cattle (451 samples) with unknown status to BLV. We found that 31.1% (229/736) and 9.5% (43/451) of samples amongst dairy and beef cattle, respectively, had IgGs to BLV. The rate of agreement with a commercial competitive ELISA was 84.3% with a κ value of 0.68. Thus, our BLVp24r iELISA is suitable to detect BLV infected animals and should be a useful tool to control BLV infection in cattle.

Animais , Bovinos , Ensaio de Imunoadsorção Enzimática/métodos , Testes Sorológicos/métodos , Leucose Enzoótica Bovina/diagnóstico , Vírus da Leucemia Bovina/imunologia , Proteínas do Capsídeo/imunologia , Anticorpos Antivirais/sangue , Proteínas Recombinantes/análise , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Ensaio de Imunoadsorção Enzimática/instrumentação , Sensibilidade e Especificidade , Leucose Enzoótica Bovina/sangue , Leucose Enzoótica Bovina/virologia , Vírus da Leucemia Bovina/isolamento & purificação , Vírus da Leucemia Bovina/genética , Proteínas do Capsídeo/análise , Proteínas do Capsídeo/genética
Mem. Inst. Oswaldo Cruz ; 112(7): 520-522, July 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-841817


This study aimed to detect dengue virus (DENV) serotypes in serum samples obtained in Matamoros Tamaulipas, Mexico, and to determine the concordance of conventional nested reverse transcriptase polymerase chain reaction (RT-PCR) and a serological test [enzyme-linked immunosorbent assay (ELISA NS1)]. Here, we detected mixed infections consisting of four serotypes of DENV. The most prevalent serotype was DENV-1, followed by DENV-4. This is the first report of DENV-4 in our region. Mixed infections were also detected in 21.5% of samples, and the predominant coinfection consisted of DENV-1 and DENV-2. Therefore, continuous epidemiological surveillance of DENV in this area is required to predict future forms of dengue heterologous infections and the effect of this on health care.

Humanos , Masculino , Ensaio de Imunoadsorção Enzimática , Reação em Cadeia da Polimerase , DNA Polimerase Dirigida por RNA , Dengue/diagnóstico , Dengue/virologia , Vírus da Dengue/genética , Sorogrupo , Anticorpos Antivirais/sangue , México
Mem. Inst. Oswaldo Cruz ; 112(6): 428-436, June 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-841805


BACKGROUND During pregnancy, toxoplasmosis and rubella can cause serious damage to the mother and the foetus through vertical transmission. Early diagnosis enables implementation of health measures aimed at preventing vertical transmission and minimising damage caused by these diseases. OBJECTIVE Here, we report the development of a multiplex assay for simultaneous detection of IgG antibodies produced during toxoplasmosis and rubella infection. METHODS This assay is based on xMap technology. Initially, by singleplex assays, we evaluated the following antigens: one Toxoplasma gondii lysate; two antigenic extracts of T. gondii (TOX8131 and TOX8122); fragments of T. gondii antigens [SAG-1 (amino acids 45-198), GRA-7 (24-100), GRA-1 (57-149), ROP-4, and MIC-3 (234-306)]; two chimeric antigens composed of fragments of SAG-1, GRA-7, and P35 (CTOX and CTOXH); and fragments of Rubella virus antigens [E-1 (157-176, 213-239, 374-390), E-2 (31-105), and C (1-123)]. FINDINGS A multiplex assay to simultaneously diagnose toxoplasmosis and rubella was designed with the best-performing antigens in singleplex and multiplex assays, which included CTOXH, T. gondii lysate, TOX8131, E-1, and E-2. The multiplex assay showed 100% sensitivity and specificity for anti-T. gondii IgG detection and 95.6% sensitivity and 100% specificity for anti-R. virus IgG detection. MAIN CONCLUSIONS We found that, despite the difficulties related to developing multiplex systems, different types of antigens (extracts and recombinant proteins) can be used to develop high-performance diagnostic tests. The assay developed is suitable to screen for prior T. gondii and R. virus infections, because it is a rapid, high-throughput, low-cost alternative to the current standard diagnostic tools, which require multiple individual tests.

Humanos , Vírus da Rubéola/imunologia , Toxoplasma/imunologia , Anticorpos Antiprotozoários/sangue , Toxoplasmose/imunologia , Anticorpos Antivirais/sangue , Rubéola (Sarampo Alemão)/diagnóstico , Imunoensaio , Sensibilidade e Especificidade , Reação em Cadeia da Polimerase Multiplex
Rev. panam. salud pública ; 41: e56, 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-961706


ABSTRACT Objective To develop and evaluate serological methods for chikungunya diagnosis and research in Nicaragua. Methods Two IgM ELISA capture systems (MAC-ELISA) for diagnosis of acute chikungunya virus (CHIKV) infections, and two Inhibition ELISA Methods (IEM) to measure total antibodies against CHIKV were developed using monoclonal antibodies (mAbs) and hyperimmune serum at the National Virology Laboratory of Nicaragua in 2014-2015. The sensitivity, specificity, predictive values, and agreement of the MAC-ELISAs were obtained by comparing the results of 198 samples (116 positive; 82 negative) with the Centers for Disease Control and Prevention's IgM ELISA (Atlanta, Georgia, United States; CDC-MAC-ELISA). For clinical evaluation of the four serological techniques, 260 paired acute and convalescent phase serum samples of suspected chikungunya cases were used. Results All four assays were standardized by determining the optimal concentrations of the different reagents. Processing times were substantially reduced compared to the CDC-MAC-ELISA. For the MAC-ELISA systems, a sensitivity of 96.6% and 97.4%, and a specificity of 98.8% and 91.5% were obtained using mAb and hyperimmune serum, respectively, compared with the CDC method. Clinical evaluation of the four serological techniques versus the CDC real-time RT-PCR assay resulted in a sensitivity of 95.7% and a specificity of 88.8%-95.9%. Conclusion Two MAC-ELISA and two IEM systems were standardized, demonstrating very good quality for chikungunya diagnosis and research demands. This will achieve more efficient epidemiological surveillance in Nicaragua, the first country in Central America to produce its own reagents for serological diagnosis of CHIKV. The methods evaluated here can be applied in other countries and will contribute to sustainable diagnostic systems to combat the disease.

RESUMEN Objetivo Elaborar y evaluar métodos serológicos para el diagnóstico y la investigación del chikungunya. Métodos Se elaboraron dos sistemas de ELISA de captura de IgM (MAC-ELISA por sus siglas en inglés) para el diagnóstico de la infección aguda por el virus de (CHIKV) y dos métodos de ELISA de inhibición (MEI) para determinar el valor cuantitativo de los anticuerpos totales contra el CHIKV, en el Laboratorio Nacional de Virología de Nicaragua en 2014-2015, para lo cual se utilizaron anticuerpos monoclonales (AcMo) y sueros hiperinmunes. Se determinó la sensibilidad, la especificidad y los valores predictivos, así como la concordancia de los MAC-ELISA, comparando los resultados de 198 muestras (116 positivas y 82 negativas) con el ELISA de los Centros para el Control y la Prevención de Enfermedades de los Estados Unidos (Atlanta; MAC-ELISA-CDC). Para la evaluación clínica de las cuatro técnicas serológicas, se emplearon 260 muestras de suero obtenidas en la fase aguda y en la fase de convalecencia de presuntos casos de chikungunya. Resultados Se estandarizaron los cuatro métodos analíticos determinando las concentraciones óptimas de los diferentes reactivos. La duración del procesamiento se redujo sustancialmente en comparación con el MAC-ELISA-CDC. Con los sistemas de MAC-ELISA, se obtuvo una sensibilidad del 96,6% y del 97,4% y una especificidad del 98,8% y del 91,5% al utilizar AcMo y suero hiperinmune, respectivamente, en comparación con el método de los CDC. La evaluación clínica de las cuatro técnicas serológicas, en comparación con la PCR en tiempo real de los CDC, arrojó una sensibilidad del 95,7% y una especificidad del 88,8%-95,9%. Conclusiones Se estandarizaron dos sistemas de ELISA-MAC y dos de MEI y se comprobó que poseen la calidad adecuada para el diagnóstico y las investigaciones del chikungunya, con lo cual mejorará la eficiencia de la vigilancia epidemiológica en Nicaragua, el primer país centroamericano que produce sus propios reactivos para el diagnóstico serológico del CHIKV. Los métodos estudiados en este trabajo pueden aplicarse en otros países y contribuyen al desarrollo de sistemas de diagnóstico sostenibles para combatir la enfermedad.

Vírus Chikungunya/imunologia , Febre de Chikungunya/diagnóstico , Febre de Chikungunya/epidemiologia , Anticorpos Antivirais/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Nicarágua/epidemiologia
Rev. panam. salud pública ; 41: e59, 2017. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-961709


RESUMEN Objetivo Estimar la seroprevalencia, la tasa de ataque clínica y la proporción de infecciones subclínicas por chikungunya, Métodos Se realizó un estudio transversal en 39 sitios distribuidos en todo el territorio nacional de Nicaragua en octubre 2015. Se recopiló información demográfica y clínica a través de una encuesta personal. Se recolectaron muestras hemáticas para detectar la presencia de anticuerpos antivirus chikungunya utilizando el método de ELISA de inhibición desarrollado por el Centro Nacional de Diagnóstico y Referencia. Se utilizaron modelos lineales generalizados y modelos de multinivel de Poisson en el análisis de los resultados. Resultados Se enrolaron 11 722 participantes mayores de dos años de edad y se procesaron 11 280 muestras. En el nivel nacional, la seroprevalencia fue de 32,8% (IC95% [intervalo de confianza de 95%]: 31,9-33,6), con una tasa de ataque clínica de 26,5% (IC95%: 25,7-27,3) y una proporción de infecciones subclínicas de 19,1% (IC95%: 17,8-20,4). Se observó variabilidad en la seroprevalencia de los 39 sitios, y los que presentaron mayor índice de infestación por el vector mostraron una mayor seroprevalencia. A nivel individual, esta fue más elevada en los participantes mayores de 11 años. Conclusión Este es el primer estudio sobre la seroprevalencia de chikungunya en América Latina continental desde su introducción, en el que se determinaron la prevalencia a nivel nacional, la tasa de ataque clínico y la proporción de infecciones subclínicas. El modelo utilizado, con una amplia participación comunitaria y el rol rector del Ministerio de Salud de Nicaragua, puede constituir un ejemplo para la realización de estudios similares en la región.

ABSTRACT Objective Estimate seroprevalence, clinical case rate, and proportion of subclinical infections from chikungunya. Methods A cross-sectional study was conducted in October 2015 at 39 sites distributed across Nicaragua. Demographic and clinical information was compiled through a personal survey. Blood samples were collected to detect chikungunya antibodies using the ELISA inhibition method developed by Nicaragua's National Diagnostic and Reference Center. Results were analyzed using generalized linear models and multilevel Poisson models. Results A total of 11 722 participants aged >2 years were enrolled and 11 280 samples were processed. National seroprevalence was 32.8% (95% CI [95% confidence interval]: 31.9-33.6), with a clinical case rate of 26.5% (95% CI: 25.7-27.3) and a proportion of subclinical infections of 19.1% (95% CI: 17.8-20.4). Seroprevalence varied among the 39 sites and was greater at sites with higher vector infestation indices. Individually, seroprevalence was higher in participants aged >11 years. Conclusion Since its introduction, this is the first study on chikungunya seroprevalence in continental Latin America to determine national prevalence, clinical case rate, and proportion of subclinical infections. The study model, employing broad community participation and leadership by the Ministry of Health of Nicaragua, can be an example for conducting similar studies in the region.

Humanos , Vírus Chikungunya/imunologia , Febre de Chikungunya/diagnóstico , Febre de Chikungunya/epidemiologia , Anticorpos Antivirais/sangue , Nicarágua/epidemiologia
Rev. Inst. Med. Trop. Säo Paulo ; 59: e2, 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-842764


ABSTRACT Introduction: The World Health Organization (WHO) recommends one single dose of the Yellow Fever (YF) vaccine based on studies of antibody persistency in healthy adults. We assessed the prevalence and titers of YF virus neutralizing antibodies in previously vaccinated persons aged ≥ 60 years, in comparison to younger adults. We also evaluated the correlation between antibody titers and the time since vaccination among participants who received one vaccine dose, and the seropositivity among participants vaccinated prior to or within the past 10 years. Methods: previously vaccinated healthy persons aged ≥ 18 years were included. YF virus neutralizing antibody titers were determined by means of the 50% Plaque Reduction Neutralization Test. Results: 46 persons aged ≥ 60 years and 48 persons aged 18 to 59 years were enrolled. There was no significant difference in the prevalence of YF virus neutralizing antibodies between the two groups (p = 0.263). However, titers were significantly lower in the elderly (p = 0.022). There was no correlation between YF virus neutralizing antibody titers and the time since vaccination. There was no significant difference in seropositivity among participants vaccinated prior to or within the past 10 years. Conclusions: the clinical relevance of the observed difference in YF virus neutralizing antibody titers between the two groups is not clear.

Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Adulto Jovem , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Vacina contra Febre Amarela/imunologia , Vírus da Febre Amarela/imunologia , Febre Amarela/prevenção & controle , Fatores Etários , Brasil , Imunoglobulina M/sangue , Febre Amarela/imunologia
Braz. J. Vet. Res. Anim. Sci. (Online) ; 54(1): 88-91, 2017. tab.
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-846779


Leptospirosis is a systemic disease caused by the species of bacteria Leptospira spp., which affects human beings, domestic and wild animals. The present study searched the presence of antibodies against Leptospira spp. in the canine population of the city Teresina, Piauí, and the most common serovars. Blood samples from 425 stray dogs were collected in the local zoonosis center in Teresina from July 2010 to January 2012 and submitted to the Microscopic Seroagglutination Test (MAT). This study found an average infection rate of 17.41% (IC 95%; 13,8 ­ 21,0) by 11 different serovars; the four most frequent were Canicola (18.9%), Autumnalis (16.2%), Icterohaemorrhagiae (12.1%), and Butembo (12.1%). The questions raised in this study indicated the occurrence of Leptospira spp infection in dogs of Terezina- Piaui, Brazil.(AU)

A leptospirose é uma doença sistêmica causada por bactéria Leptospira spp. que afeta seres humanos, animais domésticos e selvagens. O presente trabalho investigou a presença de anticorpos anti-Leptospira spp. na população canina da cidade de Teresina-Piauí, e os respectivos sorovares predominantes. Amostras de sangue de 425 cães foram coletadas no Centro de Controle de Zoonoses de Teresina, no período de julho de 2010 a janeiro de 2012, e submetidas à prova de Soroaglutinação Microscópica (SAM). Este estudo encontrou uma taxa de infecção média com 17,41% (IC 95%; 13,8 ­ 21,0) e 11 sorovares reagentes, sendo os prevalentes Canicola (18,9%), Autumnalis (16,2%), Icterohaemorrhagiae (12,1%) e Butembo (12,1%). As questões levantadas neste estudo indicam a ocorrência de infecção por Leptospira spp em cães da cidade de Teresina-Piauí, Brasil.(AU)

Animais , Cães , Anticorpos Antivirais/análise , Leptospira/isolamento & purificação , Leptospirose/epidemiologia
Mem. Inst. Oswaldo Cruz ; 111(4): 258-266, Apr. 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-779000


This study was conducted to analyse the course and the outcome of the liver disease in the co-infected animals in order to evaluate a possible synergic effect of human parvovirus B19 (B19V) and hepatitis A virus (HAV) co-infection. Nine adult cynomolgus monkeys were inoculated with serum obtained from a fatal case of B19V infection and/or a faecal suspension of acute HAV. The presence of specific antibodies to HAV and B19V, liver enzyme levels, viraemia, haematological changes, and necroinflammatory liver lesions were used for monitoring the infections. Seroconversion was confirmed in all infected groups. A similar pattern of B19V infection to human disease was observed, which was characterised by high and persistent viraemia in association with reticulocytopenia and mild to moderate anaemia during the period of investigation (59 days). Additionally, the intranuclear inclusion bodies were observed in pro-erythroblast cell from an infected cynomolgus and B19V Ag in hepatocytes. The erythroid hypoplasia and decrease in lymphocyte counts were more evident in the co-infected group. The present results demonstrated, for the first time, the susceptibility of cynomolgus to B19V infection, but it did not show a worsening of liver histopathology in the co-infected group.

Masculino , Vírus da Hepatite A , Hepatite A/complicações , Falência Hepática Aguda/virologia , Macaca fascicularis/virologia , Infecções por Parvoviridae/complicações , Parvovirus B19 Humano , Anticorpos Antivirais/sangue , Coinfecção/virologia , Modelos Animais de Doenças , Vírus da Hepatite A/imunologia , Hepatite A/imunologia , Infecções por Parvoviridae/imunologia , Parvovirus B19 Humano/imunologia , Viremia
Braz. j. microbiol ; 47(1): 231-242, Jan.-Mar. 2016. tab
Artigo em Inglês | LILACS | ID: lil-775108


Abstract This study was designed with the goal of adding as much information as possible about the role of pigeons (Columba livia) and chickens (Gallus gallus) in Newcastle disease virus epidemiology. These species were submitted to direct experimental infection with Newcastle disease virus to evaluate interspecies transmission and virus-host relationships. The results obtained in four experimental models were analyzed by hemagglutination inhibition and reverse transcriptase polymerase chain reaction for detection of virus shedding. These techniques revealed that both avian species, when previously immunized with a low pathogenic Newcastle disease virus strain (LaSota), developed high antibody titers that significantly reduced virus shedding after infection with a highly pathogenic Newcastle disease virus strain (São Joao do Meriti) and that, in chickens, prevent clinical signs. Infected pigeons shed the pathogenic strain, which was not detected in sentinel chickens or control birds. When the presence of Newcastle disease virus was analyzed in tissue samples by RT-PCR, in both species, the virus was most frequently found in the spleen. The vaccination regimen can prevent clinical disease in chickens and reduce viral shedding by chickens or pigeons. Biosecurity measures associated with vaccination programs are crucial to maintain a virulent Newcastle disease virus-free status in industrial poultry in Brazil.

Animais , Doença de Newcastle/patologia , Doença de Newcastle/virologia , Vírus da Doença de Newcastle/crescimento & desenvolvimento , Estruturas Animais/virologia , Anticorpos Antivirais/sangue , Brasil , Galinhas , Columbidae , Modelos Animais de Doenças , Transmissão de Doença Infecciosa , Testes de Inibição da Hemaglutinação , Interações Hospedeiro-Patógeno , Doença de Newcastle/imunologia , Doença de Newcastle/transmissão , Vírus da Doença de Newcastle/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Eliminação de Partículas Virais
Cad. saúde pública ; 32(1): e00095815, 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-772666


Abstract Dengue cases have increased in younger age groups in Brazil. Maternal anti-dengue antibodies can have a protective effect in the first months of life, but their decline can increase the risk of severe dengue. A prospective birth cohort was established in 2011-2012 in the city of Recife, Pernambuco State, Brazil, to determine the incidence of serotype-specific dengue infection and the kinetics of transferred maternal anti-dengue antibodies in the first years of life. This article describes the design, methods and preliminary results of this cohort study. 354 children underwent clinical and laboratory monitoring for two years, with 15% losses to follow-up. The overall rate of new infections was approximately 10% in the first year of follow-up. Information on the force of serotype-specific dengue infection and the evaluation of transferred maternal antibodies can contribute to understanding dengue etiopathogenesis.

Resumo Casos de dengue têm aumentado em grupos etários mais jovens no Brasil. Anticorpos antidengue maternos podem exercer efeito protetor nos primeiros meses de vida, mas seu declínio pode aumentar o risco de dengue grave. Uma coorte de nascimento prospectiva foi estabelecida na cidade do Recife, Pernambuco, Brasil, entre 2011-2012, para determinar a incidência de infecção sorotipo-específica do dengue e cinética dos anticorpos antidengue materno-transferidos nos primeiros anos de vida. Este artigo descreve o desenho, os métodos e resultados preliminares deste estudo de coorte. Trezentas e cinquenta e quatro crianças foram acompanhadas clínico e laboratorialmente por dois anos, com 15% de perdas de seguimento. A taxa global de novas infecções foi de aproximadamente 10% na coorte de crianças no primeiro ano de seguimento. Informações sobre a força de infecção sorotipo-específica do dengue nos primeiros anos de vida, bem como a avaliação da cinética de anticorpos materno-transferidos poderão contribuir para a compreensão da etiopatogenia da doença.

Resumen Los casos de dengue han aumentado en los grupos de edad más jóvenes en Brasil. Los anticuerpos antidengue maternos pueden ejercer un efecto protector en los primeros meses de vida, pero su decremento puede aumentar el riesgo de dengue grave. Una cohorte de nacimientos prospectiva se estableció en la ciudad de Recife, Pernambuco, Brasil, entre 2011-2012, para determinar la incidencia de infección serotipo-específica de dengue y la cinética de los anticuerpos antidengue materno-transferidos durante los primeros años de vida. Este artículo describe el diseño, los métodos y resultados preliminares de este estudio de cohorte. 354 niños fueron acompañados clínicamente y en laboratorio durante dos años, con un 15% de pérdidas en el seguimiento. La tasa global de nuevas infecciones fue de aproximadamente un 10% en la cohorte de niños durante el primer año de seguimiento. La información sobre la fuerza de infección serotipo-específica del dengue en los primeros años de vida, así como la evaluación de la cinética de los anticuerpos materno-transferidos, podrá contribuir a la comprensión de la etiopatogenia de la enfermedad.

Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Anticorpos Antivirais/sangue , Vírus da Dengue/imunologia , Dengue/epidemiologia , Doenças Endêmicas , Brasil/epidemiologia , Dengue/imunologia , Ensaio de Imunoadsorção Enzimática , Métodos Epidemiológicos , Imunidade Materno-Adquirida , Imunoglobulina G/sangue , Imunoglobulina M/sangue
Recife; s.n; 2016. 97 p. ilus, graf, tab.
Tese em Português | LILACS | ID: biblio-870271


Anticorpos antidengue materno transferidos têm sido implicados na imunopatogênese da dengue grave em lactentes. Postula-se que esses anticorpos possuam um papel distinto durante os primeiros anos de vida: ao nascimento, anticorpos antidengue materno adquiridos conferem proteção, e em seguida declinam a níveis subneutralizantes capazes de facilitar a infecção pelo vírus dengue (DENV) mediante o mecanismo de ADE (Antibody dependent enhancement), aumentando o risco de ocorrência das formas graves da dengue. Estudos prospectivos conduzidos em lactentes Asiáticos têm mostrado que o pico de anticorpos materno adquiridos com a capacidade de mediar aumento da infecção pelo DENV ocorre entre o sexto e o nono mês de vida, o que correlaciona com a epidemiologia da dengue grave em lactentes dessa região. Esta tese descreve o perfil de imunidade materna antidengue e a transferência placentária de anticorpos dengue-específicos em pares mãe-cordão recrutados em um estudo de coorte prospectivo conduzido na cidade do Recife, Nordeste do Brasil. Adicionalmente, esse trabalho analisa o papel dos níveis de IgG total maternos e da imunidade antidengue materna na transferência de anticorpos ao feto. Na coorte de lactentes, a tese avalia a cinética de declínio dos anticorpos antidengue materno-transferidos e sua capacidade de mediar ADE durante os primeiros anos de vida. Níveis de IgG DENV-especifico e de anticorpos neutralizantes sorotipo específicos (DENV1-4) foram determinados em 376 pares mãe-cordão. A cinética de anticorpos materno transferidos neutralizantes e/ou mediadores de ADE foi investigada em uma subamostra das crianças inseridas na coorte. A maior parte das gestantes apresentava imunidade ao sorotipo DENV-3 (53,7 por cento) ou a combinação DENV-3/ DENV-4 (30,6 por cento)...

Maternal-fetal transferred Dengue virus (DENV)-specific antibodies have been implicated in the immunopathogenesis of dengue during infancy. These antibodies play a dual role in infants during the first year of life: first, maternally-acquired antibodies confer protection at birth, and then decline to a lower level capable of enhance DENV infection through the mechanism of ADE (antibody-dependent enhancement), increasing the chance of development of severe dengue. Prospective studies conducted in Asian infants have provided evidence that the peak of enhancing activity by maternally transferred dengue antibodies occurs between 6th to 9th month of age, which correlates with the age-related epidemiology of the dengue severe cases in this region. This thesis describes the placental transfer of dengue-specific antibodies in mother-cord pairs enrolled in a prospective cohort study carried out in the city of Recife, Northeast Brazil. Moreover, we analyze the role of maternal total IgG levels and dengue immunity in the transference of dengue-specific antibodies to the fetus. In the cohort of children, we determine the kinetics of Enhancing Activity (EA) by maternally acquired dengue antibodies during their first year of life. DENV-specific IgG and serotype-specific (DENV1-4) neutralizing antibody (Nab) levels were assessed in 376 mother-cord paired samples...

Humanos , Dengue/epidemiologia , Imunidade Materno-Adquirida , Lactente , Vírus da Dengue/imunologia , Anticorpos Antivirais/sangue , Anticorpos Neutralizantes/sangue , Brasil , Estudos de Coortes , Imunoglobulina G/sangue
Rev. chil. infectol ; 32(6): 618-627, tab
Artigo em Espanhol | LILACS | ID: lil-773267


Background: Dengue is an infection of great global importance with different clinical presentations. Objective: To establish the seroprevalence of infection by the dengue virus in a district of the Paraguayan Chaco. Material and Methods: Cross-sectional study in 418 inhabitants of three villages in the district of Villa Hayes, Paraguay, using a probabilistic household sampling, a questionnaire and blood sampling. Antibodies were determined by the ELISA capture IgG anti dengue method and factors associated with seroprevalence were evaluated. Results: The overall seroprevalence for dengue virus infection was 24,2% (CI95%: 20,2%-28,6%); 34% (n: 142) of respondents reported history of dengue in the previous 10-year period. Of the 276 people (66%) who reported no history of dengue infection, 37 (13%) tested positive, which points out asymptomatic individuals. The main factors associated with infection were: males with significantly higher prevalence than women (31%); to be over 60 years of age (44%), be residents of Villa Hayes (31,1%). No association with educational level or monthly income of the participants, nor housing condition, drinking water source or type of bathroom were observed. The larval infestation rate was 0,51%. Conclusions: The relatively low seroprevalence of infection by the dengue virus is consistent with the small size of the district and highlights the potential risk of infection in future epidemics.

Introducción: El dengue es una infección de gran importancia mundial con diferentes formas clínicas de presentación. Objetivo: Establecer la seroprevalencia de infección por el virus del dengue en un distrito del Chaco paraguayo. Material y Métodos: Estudio transversal en 418 habitantes de tres localidades del Distrito de Villa Hayes, Paraguay, mediante un muestreo probabilístico por hogares, aplicación de cuestionario y toma de muestras sanguíneas. Se buscaron anticuerpos por el método ELISA de captura de IgG anti dengue y se evaluaron factores asociados a la seroprevalencia. Resultados: La seroprevalencia global para el virus del dengue fue 24,2% (IC 95%: 20,2%-28,6%); 34% (n: 142) de los encuestados refirió haber enfermado alguna vez de dengue en el período de 10 años anteriores. De las 276 personas (66%) que refirieron no haber enfermado de dengue, 37 (13%) resultaron positivos en la prueba serológica, lo que destaca la condición de asintomáticos con que cursaron la enfermedad. Los principales factores vinculados con la infección fueron: sexo masculino (prevalencia: 31,7%); ser mayor de 60 años (prevalencia: 44%); residencia en la localidad de Villa Hayes (prevalencia: 31,1%). No se observó asociación con el nivel educativo o ingreso mensual de los encuestados, tampoco con el tipo de vivienda, fuente de agua potable o tipo de baño. El índice de infestación larvaria fue 0,51%. Conclusiones: La relativa baja seroprevalencia de la infección por el virus del dengue es consistente con el tamaño pequeño del distrito y demuestra el riesgo potencial de enfermar en futuras epidemias.

Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Anticorpos Antivirais/sangue , Vírus da Dengue/imunologia , Dengue/epidemiologia , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Imunoglobulina G/sangue , Prevalência , Estudos Soroepidemiológicos , Fatores Socioeconômicos
Rev. Inst. Med. Trop. Säo Paulo ; 57(6): 497-503, Nov.-Dec. 2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-770116


The outbreaks of rabies in humans transmitted by Desmodus rotundus in 2004 and 2005, in the northeast of the Brazilian State of Para, eastern Amazon basin, made this a priority area for studies on this zoonosis. Given this, the present study provides data on this phenomenon in an urban context, in order to assess the possible circulation of the classic rabies virus (RABV) among bat species in Capanema, a town in the Amazon basin. Bats were collected, in 2011, with mist nets during the wet and dry seasons. Samples of brain tissue and blood were collected for virological and serological survey, respectively. None of the 153 brain tissue samples analyzed tested positive for RABV infection, but 50.34% (95% CI: 45.67-55.01%) of the serum samples analyzed were seropositive. Artibeus planirostris was the most common species, with a high percentage of seropositive individuals (52.46%, 95% CI: 52.31 52.60%). Statistically, equal proportions of seropositive results were obtained in the rainy and dry seasons (c2 = 0.057, d.f. = 1, p = 0.88). Significantly higher proportions of males (55.96%, 95% CI: 48.96-62.96%) and adults (52.37%, 95% CI: 47.35-57.39%) were seropositive. While none of the brain tissue samples tested positive for infection, the high proportion of seropositive specimens indicates that RABV may be widespread in this urban area.

Os surtos de raiva em humanos transmitida por Desmodus rotundus em 2004 e 2005 no nordeste do estado do Pará, Brasil, Amazônia Oriental, fizeram desta uma área prioritária para estudos sobre essa zoonose. Diante disso, o presente estudo fornece dados sobre esse fenômeno em contexto urbano, afim de avaliar uma possível circulação do vírus clássico da raiva (RABV) entre espécies de morcegos em Capanema, cidade localizada na bacia Amazônica. Os morcegos foram coletados em 2011, com auxílio de redes de espera durante as estações seca e chuvosa. Amostras de encéfalo e de sangue foram coletadas para o diagnóstico virológico e sorológico, respectivamente. Das 153 amostras de encéfalo analisadas, nenhuma encontrou-se positiva para infecção pelo RABV, porém, 50,34% (95% CI: 45,67-55,01) das amostras de soro analisadas estavam soropositivas. Artibeus planirostris foi a espécie mais comum, e seu percentual de indivíduos soropositivos foi bem elevado (52.46%, 95% CI: 52,31-52,60). Porções estatisticamente iguais de soropositivos foram registrados nas estações (c2 = 0,057, d.f. = 1, p = 0,88). Uma porção significativamente elevada de machos (55,96%, 95% CI: 48,96%-62,96%), e adultos (52,37%, 95% CI: 47,35%-57,39%) foram soropositivos. Apesar de nenhuma das amostras de encéfalo terem sido positivas para raiva, a alta proporção de espécimes soropositivos indica uma possível circulação do RABV nessa área urbana.

Animais , Anticorpos Antivirais/sangue , Quirópteros/virologia , Vírus da Raiva/imunologia , Vírus da Raiva/isolamento & purificação , Raiva/veterinária , Saúde da População Urbana , Brasil , Encéfalo/virologia , Distribuição de Qui-Quadrado , Quirópteros/sangue , Cidades/estatística & dados numéricos , Vetores de Doenças , Raiva/sangue , Raiva/diagnóstico , Estações do Ano , Estudos Soroepidemiológicos , Fatores Sexuais
Rev. Inst. Med. Trop. Säo Paulo ; 57(5): 455-457, Sept.-Oct. 2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-766280


SUMMARY We describe the case of an eight-year-old boy with X-linked agammaglobulinemia who developed mild varicella despite regular intravenous immunoglobulin (IVIG) therapy. He maintained protective antibody levels against varicella and the previous batches of IVIG that he received had adequate varicella-specific IgG levels. The case illustrates that IVIG may not prevent VZV infection.

RESUMO Relatamos o caso de uma criança com agamaglobulinemia ligada ao X, sexo masculino, oito anos de idade, que desenvolveu quadro de varicela leve, apesar do tratamento regular com imunoglobulina intravenosa (IVIG). O paciente mantinha níveis adequados de imunoglobulina (IgG) contra varicela, assim como, os últimos lotes de IVIG por ele recebido também apresentavam níveis adequados do anticorpo específico. O caso ilustra que o tratamento regular com IVIG não é suficiente para prevenir a infecção pelo vírus da varicela-zoster.

Criança , Humanos , Masculino , Agamaglobulinemia/imunologia , Anticorpos Antivirais/sangue , Varicela/diagnóstico , Doenças Genéticas Ligadas ao Cromossomo X/imunologia , /imunologia , Soros Imunes/administração & dosagem , Imunoglobulina G/sangue , Agamaglobulinemia/tratamento farmacológico , Varicela/imunologia , Varicela/prevenção & controle , Doenças Genéticas Ligadas ao Cromossomo X/tratamento farmacológico , Falha de Tratamento
Rev. Soc. Bras. Med. Trop ; 48(5): 514-523, Sept.-Oct. 2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-763338


ABSTRACTINTRODUCTION:While no single factor is sufficient to guarantee the success of influenza vaccine programs, knowledge of the levels of immunity in local populations is critical. Here, we analyzed influenza immunity in a population from Southern Brazil, a region with weather conditions that are distinct from those in the rest of country, where influenza infections are endemic, and where greater than 50% of the population is vaccinated annually.METHODS:Peripheral blood mononuclear cells were isolated from 40 individuals. Of these, 20 had received the H1N1 vaccine, while the remaining 20 were unvaccinated against the disease. Cells were stimulated in vitro with the trivalent post-pandemic influenza vaccine or with conserved major histocompatibility complex I (MHC I) peptides derived from hemagglutinin and neuraminidase. Cell viability was then analyzed by [3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide)]-based colorimetric assay (MTT), and culture supernatants were assayed for helper T type 1 (Th1) and Th2-specific cytokine levels.RESULTS:Peripheral blood lymphocytes from vaccinated, but not unvaccinated, individuals exhibited significant proliferation in vitro in the presence of a cognate influenza antigen. After culturing with vaccine antigens, cells from vaccinated individuals produced similar levels of interleukin (IL)-10 and interferon (IFN)-γ, while those from unvaccinated individuals produced higher levels of IFN-γ than of IL-10.CONCLUSIONS:Our data indicate that peripheral blood lymphocytes from vaccinated individuals are stimulated upon encountering a cognate antigen, but did not support the hypothesis that cross-reactive responses related to previous infections can ameliorate the immune response. Moreover, monitoring IL-10 production in vaccinated individuals could comprise a valuable tool for predicting disease evolution.

Adulto , Humanos , Adulto Jovem , Anticorpos Antivirais/imunologia , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza/imunologia , Influenza Humana/imunologia , Linfócitos/imunologia , Anticorpos Antivirais/sangue , Brasil/epidemiologia , /imunologia , Estudos Transversais , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Interferon gama/biossíntese , /biossíntese , Leucócitos Mononucleares/imunologia , Pandemias
Braz. j. microbiol ; 46(3): 867-874, July-Sept. 2015. tab, ilus
Artigo em Inglês | LILACS | ID: lil-755808


This study was conducted in order to evaluate the transmission of caprine lentivirus to sheep using different experimental groups. The first one (colostrum group) was formed by nine lambs receiving colostrum from goats positive for small ruminant lentiviruses (SRLV). The second group (milk group) was established by nine lambs that received milk of these goats. Third was a control group, consisting of lambs that suckled colostrum and milk of negative mothers. Another experimental group (contact group) was formed by eight adult sheep, confined with two naturally infected goats. The groups were monitored by immunoblotting (IB), enzyme-linked immunosorbent assay (ELISA), agar gel immunodiffusion (AGID) and nested polymerase chain reaction (nPCR). All lambs that suckled colostrum and milk of infected goats and six sheep of the contact group had positive results in the nPCR, although seroconversion was detected only in three of the exposed animals, with no clinical lentiviruses manifestation, in 720 days of observation. There was a close relationship between viral sequences obtained from infected animals and the prototype CAEV-Cork. Thus, it was concluded that SRLV can be transmitted from goats to sheep, however, the degree of adaptation of the virus strain to the host species probably interferes with the infection persistence and seroconversion rate.


Animais , Vírus da Artrite-Encefalite Caprina/patogenicidade , Colostro/virologia , Doenças das Cabras/transmissão , Infecções por Lentivirus/transmissão , Doenças dos Ovinos/transmissão , Vírus Visna-Maedi/patogenicidade , Anticorpos Antivirais/sangue , Doenças das Cabras/virologia , Cabras/virologia , Interações Hospedeiro-Patógeno/fisiologia , Infecções por Lentivirus/virologia , Ruminantes/virologia , Soroconversão/fisiologia , Doenças dos Ovinos/virologia , Ovinos/virologia