Seroepidemiology aims to understand population-level exposure and immunity to infectious disease. Serological results are normally presented as binary outcomes describing the presence or absence of antibody, despite the fact that many assays measure continuous quantities. A population's antibody titers may include information on multiple serological states - naiveté, recent infection, non-recent infection, childhood infection - not just seropositivity or seronegativity. In the first part of this thesis, I investigate 20,152 general-population serum samples from southern Vietnam collected between 2009 and 2013 from which I report antibody titers to the influenza virus HA1 protein using a continuous titer measurement from a protein microarray assay. I describe titer distributions to subtypes 2009 H1N1 and H3N2, and using a model selection approach for mixture distributions, I determine that 2009 H1N1 is best described by four titer subgroups while H3N2 is best described by three titer subgroups. For H1N1, my interpretation is that the two highest-titer subgroups correspond to recent and historical infection, which is consistent with pandemic attack rates. For H3N2 however, right-censoring of titers makes interpretations difficult to validate. To move beyond this stationary interpretation of titers, I developed two methods for analyzing this serum collection as a time series. First, I attempted to analyze mixture categories in individual time windows. This approach did not lead to a consistent temporal picture of titer change; results differed by site and were sensitive to assumptions in the mixture fitting. Second, I attempted to fit a hybrid-dynamical model with free incidence parameters. This inference was robust to parameter assumptions, consistent across sites, and in agreement with the incidence reported in Vietnam's influenza surveillance network. In addition, my new approach showed evidence that there was a second silent wave of the 2009 influenza pandemic that was not recorded in national surveillance, which is this thesis' main novel result.

Copper exposures of 400 μg/L for 5,10 and 15 days resulted in no significant differences in antibody titers of largemouth bass, Micropterus salmoides injected with Aeromonas hydrophila compared to control-injected bass. Twenty days of exposure did significantly increase titers. The control group had significantly lower antibody titers than either control-injected or copper-exposed.

Lines of White Leghorn chickens selected > 20 generations for (HA) and against (LA) antibody response to SRBC injected i.v. from 41 to 51 days of age, are now known to have diverged in primary antibody response to SRBC. Experiments described in this dissertation were designed to further evaluate the immune competence of these lines as influenced by age, diet, and a disease agent. A crossing experiment was also conducted to further describe the mode of inheritance of such competence. Humoral immunocompetence was evaluated by primary, memory, and maternal antibody responses to SRBC. Primary antibody response, measured 5, 10, and 20 days after inoculation with SRBC was greater in HA than LA chicks inoculated at 14, 21, and 28 days of age. In chicks injected at 7 days of age, a higher frequency of responders was observed for HA than LA chicks suggesting an earlier onset of immunocompetence in the high than low antibody line. Immunological memory antibody responses (secondary and tertiary) was studied in parallel experiments on two groups of chicks hatched at a 14-day interval. Chicks in both hatches were from the same matings of parental Lines HA and LA. Memory responses were evident in chicks at 14 days of age. Antibody responses to a second and third inoculation with SRBC were similar for both lines suggesting that genetic factors that influence primary and memory responses are not the same. The responses of LA chicks to repeat inoculations with SRBC were anamnestic whereas those of HA chicks initially inoculated at 28 days of age were not anamnestic. This study did not establish any major influence of nutrient density on either primary or memory immune responses even though the higher nutrient density diet improved growth performance. Assays in chicks indicated that maternal antibodies were transferred earlier into eggs laid by HA hens than in those of LA hens ( 7 to 9 days vs 10 to 12 days after inoculation) regardless of dosage administered. Response patterns whether assessed in terms of frequency of detection or magnitude of response showed divergence between the lines. Chicks of parental, reciprocal F , F , and backcrosses of 1 2 mating combinations of Lines HA and LA were injected with SRBC at 36 days of age. Contrasts between parental lines for antibody titers measured 5 and 12 days later showed higher antibody titers in HA than LA chicks. Sex-linked effects were evident because reciprocal contrasts for F crosses, individual heterosis, and 1 maternal heterosis were sex dependent. Response to marble spleen disease virus ( MSDV) measured 6 days after inoculation of chicks from parental, reciprocal F1, F2, and backcross matings of the lines, indicated that the mode of inheritance of spleen weight differed after infection. In the infected chicks, parental contrasts for absolute and relative spleen weights showed greater resistance to MSDV in LA than HA chicks. No other genetic effect was consistently important after infection. / Ph. D.

Made available in DSpace on 2014-06-11T19:27:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-18Bitstream added on 2014-06-13T19:14:32Z : No. of bitstreams: 1 borges_la_me_jabo.pdf: 248872 bytes, checksum: bb6dce02b71fa4434990be14d38d0fe8 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O herpesvírus bovino tipo 1 (BoHV-1), agente etiológico da rinotraqueite infecciosa bovina (IBR)/Vulvovaginite Pustular Bovina (IPV), tem grande importância como agente causador de problemas reprodutivos em vacas por determinar baixas taxas de concepção ou parição, acarretando consideráveis perdas econômicas para o produtor. Assim, o presente estudo conduzido em rebanhos de três fazendas (A, B e C) onde se processa a transferência de embriões (TE) no município de Prata no Estado de Minas Gerais teve como objetivo verificar as condições sorológicas de 209 animais antes do processamento biotécnico, determinar a resposta imune de esquema vacinal pré-definido e analisar a relação entre títulos médios geométricos (TMG) de anticorpos antes e depois da vacinação com os parâmetros reprodutivos de fêmeas receptoras de embriões vacinadas contra o BoHV-1. O título dos anticorpos para BoHV-1 foi determinado por meio do teste de virusneutralização (VN), conforme protocolo definido pelo Organização Mundial de Saúde Animal (OIE) e o quadro reprodutivo foi caracterizado por meio do exame de ultrassonografia transretal. Com isso, verificou-se que as prevalências de 39,7% (27/68) na fazenda A, 27,5% (11/40) na fazenda B e 36,6% (37/101) na fazenda C não foram estatisticamente diferentes; essa situação epidemiológica definiu o aumento de títulos de anticorpos para o BoHV-1 em 72,7% (152/209) dos animais pela vacinação com dose única; o maior sucesso de prenhez (75%) na 1ª TE foi observada nos animais que eram positivos e atingiram títulos acima de 256 após a vacinação; mesmo assim, no contexto estatístico, os índices gerais de gestação não tiveram influência significativa em decorrência da vacinação com dose única / The bovine herpesvirus type 1 (BoVH-1), which causes infectious bovine rhinotracheitis (IBR) / infectious pustular vulvovaginitis (IPV), has major importance as an agent that causes reproductive problems by determining low conception or calving rates causing significant economical losses for the producer. The present study, was carried out in the cattle of three farms (A, B and C), where the embryos transfer is processed (ET), at Prata municipality in Minas Gerais State, aiming to verify the serological conditions of 209 animals before biotechnical processing, to determine immune response to a pre defined vaccination schedule and to analyze the relationship between geometric mean titers (TMG) of antibodies before and after vaccination with the reproductive parameters in embryo recipient heifers vaccinated against BoHV-1. The antibodies titers of BoHV-1 were determined by the virusneutralization test (VN), according to the protocol established by the World Organization for Animal Health (OIE) and the reproductive performance was characterized by transrectal ultrasonography examination. Thus, it was verified that the prevalence rates of 39.7% (27/68) in farm A, 27.5% (11/40) in farm B and 36.6% (37/101) in farm C had no statistical difference; this epidemiological situation defined the increase of antibody titers for BoHV-1 in 72.7% (152/209) of the animals by vaccination with a single dose; the greater success of pregnancy (75%) in the first ET was observed in animals that were positive and reached titers higher than 256 after vaccination; in the statistical context, the single dose vaccination had no significative influence in the overall rates of pregnancy

Orientador: Samir Issa Samara / Banca: Sandra Possebon Gatti / Banca: Walt Yamasaki / Resumo: O herpesvírus bovino tipo 1 (BoHV-1), agente etiológico da rinotraqueite infecciosa bovina (IBR)/Vulvovaginite Pustular Bovina (IPV), tem grande importância como agente causador de problemas reprodutivos em vacas por determinar baixas taxas de concepção ou parição, acarretando consideráveis perdas econômicas para o produtor. Assim, o presente estudo conduzido em rebanhos de três fazendas (A, B e C) onde se processa a transferência de embriões (TE) no município de Prata no Estado de Minas Gerais teve como objetivo verificar as condições sorológicas de 209 animais antes do processamento biotécnico, determinar a resposta imune de esquema vacinal pré-definido e analisar a relação entre títulos médios geométricos (TMG) de anticorpos antes e depois da vacinação com os parâmetros reprodutivos de fêmeas receptoras de embriões vacinadas contra o BoHV-1. O título dos anticorpos para BoHV-1 foi determinado por meio do teste de virusneutralização (VN), conforme protocolo definido pelo Organização Mundial de Saúde Animal (OIE) e o quadro reprodutivo foi caracterizado por meio do exame de ultrassonografia transretal. Com isso, verificou-se que as prevalências de 39,7% (27/68) na fazenda A, 27,5% (11/40) na fazenda B e 36,6% (37/101) na fazenda C não foram estatisticamente diferentes; essa situação epidemiológica definiu o aumento de títulos de anticorpos para o BoHV-1 em 72,7% (152/209) dos animais pela vacinação com dose única; o maior sucesso de prenhez (75%) na 1ª TE foi observada nos animais que eram positivos e atingiram títulos acima de 256 após a vacinação; mesmo assim, no contexto estatístico, os índices gerais de gestação não tiveram influência significativa em decorrência da vacinação com dose única / Abstract: The bovine herpesvirus type 1 (BoVH-1), which causes infectious bovine rhinotracheitis (IBR) / infectious pustular vulvovaginitis (IPV), has major importance as an agent that causes reproductive problems by determining low conception or calving rates causing significant economical losses for the producer. The present study, was carried out in the cattle of three farms (A, B and C), where the embryos transfer is processed (ET), at Prata municipality in Minas Gerais State, aiming to verify the serological conditions of 209 animals before biotechnical processing, to determine immune response to a pre defined vaccination schedule and to analyze the relationship between geometric mean titers (TMG) of antibodies before and after vaccination with the reproductive parameters in embryo recipient heifers vaccinated against BoHV-1. The antibodies titers of BoHV-1 were determined by the virusneutralization test (VN), according to the protocol established by the World Organization for Animal Health (OIE) and the reproductive performance was characterized by transrectal ultrasonography examination. Thus, it was verified that the prevalence rates of 39.7% (27/68) in farm A, 27.5% (11/40) in farm B and 36.6% (37/101) in farm C had no statistical difference; this epidemiological situation defined the increase of antibody titers for BoHV-1 in 72.7% (152/209) of the animals by vaccination with a single dose; the greater success of pregnancy (75%) in the first ET was observed in animals that were positive and reached titers higher than 256 after vaccination; in the statistical context, the single dose vaccination had no significative influence in the overall rates of pregnancy / Mestre

Made available in DSpace on 2016-12-23T13:56:12Z (GMT). No. of bitstreams: 1 Aline Lyra Pereira.pdf: 1742611 bytes, checksum: fac56687c54e0ab6545343dd5ab0a212 (MD5) Previous issue date: 2012-03-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A paracoccidioidomicose (PCM) é uma micose sistêmica causada pelo fungo dimórfico Paracoccidioides brasiliensis. Está entre as infecções fúngicas mais frequentes da América Latina, sendo o Brasil o país de maior endemicidade, com maior prevalência na região Sudeste. O diagnóstico considerado por muitos autores padrão-ouro para a PCM é o encontro de células fúngicas sugestivas de Paracoccidioides brasiliensis no Exame Microscópico Direto (EMD) de escarro ou outros espécimes clínicos, como raspado de lesão, aspirado de linfonodos, biopsia, etc. As provas sorológicas têm grande importância, complementando ou substituindo o exame micológico no diagnóstico/prognóstico da doença. O objetivo do presente estudo foi comparar dois desses testes sorológicos para PCM: a imunodifusão dupla (IDD) e o ensaio imunoenzimático ELISA. A metodologia foi estabelecida comparando-se títulos de anticorpos obtidos de três grupos de pacientes: 145 amostras de soros de 83 pacientes com PCM (Grupo I), 49 doadores saudáveis (Grupo II) e 13 pacientes com IDD positiva para outras micoses pulmonares: 11 com histoplasmose e 2 com aspergilose (Grupo III). Nossos resultados mostraram que 8 (9,6%) e 5 (6,0%) dos pacientes com PCM foram falso-negativos ao teste de IDD e ELISA, respectivamente. Dentro do grupo de pacientes saudáveis, não houve casos de falso positivo na IDD, porém, 5 (10,2%) amostras foram positivas com títulos baixos no ELISA. Entre os 13 pacientes com outras micoses, o ELISA mostrou que 10 (77,0%) foram positivos enquanto a IDD não apresentou qualquer caso de reação cruzada. A sensibilidade do ELISA (93,9%) foi um pouco superior ao da IDD (90,3%). A especificidade do ELISA calculada como base o controle saudável e os pacientes com outras micoses foi 89,7% e 23,1%, respectivamente. A IDD mostrou uma especificidade de 100% para ambos os casos. Os valores preditivos positivos e negativos foram de 100% e 83,8% para IDD e de 88,5% e 90,3% para ELISA, respectivamente. A acurácia dos testes também foi calculada: a IDD teve 94,4% e o ELISA 86,2% de acurácia. / Paracoccidioidomycosis (PCM) is a systemic mycosis caused by the dimorphic fungus Paracoccidioides brasiliensis. It is among the most common fungal infections in Latin America, with Brazil being the country of highest endemicity, mainly in the Southeast part. The diagnosis considered by many authors as gold standard for the PCM is the finding of suggestive yeast cells of Paracoccidioides brasiliensis in the Direct Microscopic Examination of sputum or other clinical specimens, such as scraping the lesion, lymph node aspirate, biopsy, etc. The serological tests are of great importance, since they complement or replace the mycological examination in the diagnosis / prognosis of the disease. The aim of this study was to compare two serological tests for PCM: a double immunodiffusion (IDD) and Enzyme-Linked Immunoabsorbent Assay (ELISA). The methodology was established by comparing antibody titers obtained from three groups of patients: 145 serum samples from 83 patients with PCM (Group I), 49 healthy blood donors (Group II) and 13 patients with IDD positive for other pulmonary mycoses: 11 with histoplasmosis and 2 with aspergillosis (Group III). Our results showed that eight (9.6%) and 5 (6.0%) of patients with PCM were false negative to the IDD and ELISA tests, respectively. In the group of healthy patients, no cases of false positive in IDD were observed; however, 5 (10.2%) of samples were positive with low titers in ELISA. Among the 13 patients with other mycoses, the ELISA showed that 10 (77.0%) were positive while the IDD tests did not show any case of cross-reaction. The sensitivity of the ELISA (93.9%) was slightly higher than the IDD (90.3%). The specificity of the ELISA calculated basing on the healthy control and patients with other mycoses was 89.7% and 23.1%, respectively. IDD showed 100% of specificity for both cases. The positive predictive and negative predictive values were 100% and 83.8% for IDD and 88.5% and 90.3% for ELISA, respectively. The accuracy of the tests was also calculated: the IDD was 94.4% while ELISA was 86.2%.