Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 361
Mem. Inst. Oswaldo Cruz ; 112(8): 532-536, Aug. 2017. graf
Article in English | LILACS | ID: biblio-894866


BACKGROUND In this study, we evaluated the role of free-living domestic pigeons (Columba livia) as a reservoir of arboviruses in the city of Belém, state of Pará, Brazil. We investigated the presence of antibodies against the most prevalent arboviruses. OBJECTIVES This study was aimed at evaluating some clinical and physical parameters of domestic pigeons, including the presence of antibodies to Amazon-endemic arboviruses. METHODS Eighty-five healthy pigeons were captured in Mangal das Garças Park, in Belém, and were bled. Upon capture, the birds were subjected to a clinical examination in search of alterations that could indicate the presence of arboviruses. Blood samples were converted to serum and tested using the haemagglutination inhibition (HI) technique with a panel of 19 antigens of arboviruses circulating in the Amazon. The confirmation assay for the positive reactions to the viral species tested by HI was a neutralisation test in new-born Swiss albino mice (Mus musculus) [mouse neutralisation test (MNT)]. FINDINGS A total of 10 (11.8%) serum samples tested positive for antiflavivirus antibodies by HI. All the samples positive for the HI test were subjected to MNT for detection of viruses and yielded negative results (logarithmic neutralisation index < 1.7). MAIN CONCLUSION The results represent the first serological detection of antiarbovirus antibodies in domestic pigeons as potential hosts of arboviruses in Brazil. The detection of haemagglutination-inhibiting antibodies against genus Flavivirus indicated that there was recent contact between the analysed domestic pigeons and these arboviruses. Further studies are needed to evaluate the role of free-living pigeons in the maintenance cycle and spread of arboviruses in the Amazon.

Animals , Male , Female , Mice , Arbovirus Infections/diagnosis , Arbovirus Infections/veterinary , Arbovirus Infections/virology , Columbidae/virology , Bird Diseases/diagnosis , Bird Diseases/virology , Brazil , Hemagglutination Inhibition Tests , Disease Vectors
Braz. j. infect. dis ; 21(1): 63-70, Jan.-Feb. 2017. tab, graf
Article in English | LILACS | ID: biblio-839185


Abstract The World Health Organization influenza forecast now includes an influenza B strain from each of the influenza B lineages (B/Yamagata and B/Victoria) for inclusion in seasonal influenza vaccines. Traditional trivalent influenza vaccines include an influenza B strain from one lineage, but because two influenza B lineages frequently co-circulate, the effectiveness of trivalent vaccines may be reduced in seasons of influenza B vaccine-mismatch. Thus, quadrivalent vaccines may potentially reduce the burden of influenza compared with trivalent vaccines.In this Phase III, open-label study, we assessed the immunogenicity and safety of Southern Hemisphere inactivated quadrivalent influenza vaccine (Fluarix™ Tetra) in Brazilian adults (NCT02369341). The primary objective was to assess hemagglutination-inhibition antibody responses against each vaccine strain 21 days after vaccination in adults (aged ≥18–60 years) and older adults (aged >60 years). Solicited adverse events for four days post-vaccination, and unsolicited adverse events and serious adverse events for 21 days post-vaccination were also assessed.A total of 63 adults and 57 older adults received one dose of inactivated quadrivalent influenza vaccine at the beginning of the 2015 Southern Hemisphere influenza season. After vaccination, in adults and older adults, the hemagglutination-inhibition titers fulfilled the European licensure criteria for immunogenicity. In adults, the seroprotection rates with HI titer ≥1:40 were 100% (A/H1N1), 98.4% (A/H3N2), 100% (B/Yamagata), and 100% (B/Victoria); in older adults were 94.7% (A/H1N1), 96.5% (A/H3N2), 100% (B/Yamagata), and 100% (B/Victoria). Pain was the most common solicited local adverse events in adults (27/62) and in older adults (13/57), and the most common solicited general adverse events in adults was myalgia (9/62), and in older adults were myalgia and arthralgia (both 2/57). Unsolicited adverse events were reported by 11/63 adults and 10/57 older adults.The study showed that inactivated quadrivalent influenza vaccine was immunogenic and well-tolerated in Brazilian adults and older adults.

Humans , Male , Female , Adult , Middle Aged , Young Adult , Influenza Vaccines/immunology , Influenza, Human/immunology , Influenza, Human/prevention & control , Immunogenicity, Vaccine , Time Factors , Brazil , Hemagglutination Inhibition Tests , Influenza Vaccines/adverse effects , Vaccines, Inactivated/adverse effects , Vaccines, Inactivated/immunology , Reproducibility of Results , Age Factors , Vaccination/adverse effects , Treatment Outcome , Hemagglutination, Viral/immunology , Antibodies, Viral/blood
Infection and Chemotherapy ; : 117-122, 2017.
Article in English | WPRIM | ID: wpr-105547


BACKGROUND: In March 2013, human infection with avian influenza A (H7N9) virus emerged in China, causing serious public health concerns and raising the possibility of avian-source pandemic influenza. Thus, the development of an effective vaccine for preventing and rapidly controlling avian influenza A (H7N9) virus is needed. In this study, we evaluated the immunogenicity of a synthetic DNA vaccine against H7 HA antigens in mice. MATERIALS AND METHODS: The synthetic consensus H7 HA DNA vaccine (25 or 50 µg) was administered to BALB/c mice at 0, 14, and 28 days by intramuscular injection followed by electroporation. Humoral and cellular immune responses were analyzed in a hemagglutination inhibition test and interferon-gamma enzyme-linked immunospot (ELISpot) assay, respectively. RESULTS: H7 HA-vaccinated mice showed 100% seroprotection and seroconversion rate against H7N9 reassortant influenza virus after both second and third immunizations. The geometric mean titer by the hemagglutination inhibition test increased with an increasing number of immunizations. However, there was no significant difference in geometric titer between the two groups injected with 25 and 50 µg of H7 HA DNA vaccine after two (79.98 vs. 107.65, P = 0.39) and three (159.96 vs. 215.28, P = 0.18) doses. In addition, the ELISpot assay revealed that administration of H7 HA DNA vaccine induced potent interferon-gamma production from mouse splenocytes. CONCLUSIONS: This study demonstrated the humoral and cellular immunogenicity of synthetic consensus H7 HA DNA vaccine in mice. This work demonstrates the potential of the H7 HA DNA vaccine as an efficient tool for the rapid control of emerging influenza A (H7N9) virus.

Animals , China , Consensus , DNA , Electroporation , Enzyme-Linked Immunospot Assay , Hemagglutination Inhibition Tests , Humans , Immunity, Cellular , Immunization , Influenza in Birds , Influenza, Human , Injections, Intramuscular , Interferon-gamma , Mice , Orthomyxoviridae , Pandemics , Public Health , Seroconversion
Braz. j. microbiol ; 47(1): 231-242, Jan.-Mar. 2016. tab
Article in English | 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.

Animals , Newcastle Disease/pathology , Newcastle Disease/virology , Newcastle disease virus/growth & development , Animal Structures/virology , Antibodies, Viral/blood , Brazil , Chickens , Columbidae , Disease Models, Animal , Disease Transmission, Infectious , Hemagglutination Inhibition Tests , Host-Pathogen Interactions , Newcastle Disease/immunology , Newcastle Disease/transmission , Newcastle disease virus/immunology , Reverse Transcriptase Polymerase Chain Reaction , Virus Shedding
Chinese Journal of Virology ; (6): 141-144, 2016.
Article in Chinese | WPRIM | ID: wpr-296206


Preparation of maternal strain A/PR/8/34 HA antiserum for influenza virus classical reassortment. A/PR/8/34 virus was digested by bromelain after inactivation and purification. 5%-20% sucrose continuous density gradient centrifugation method was used to purify HA protein. SIRD method was used to select the target protein. SDS-PAGE method was used to identified HA protein. High Immunogenic A/PR/8/34 HA protein was successfully prepared and HI titer reached 10240. High purity HA antiserum was identified by SIRD method. The key reagent in the classical reassortment of influenza virus was prepared, and the complete set of technical methods were explored, which laid the foundation for the independent research and development of seasonal influenza vaccine strains of China.

Animals , Antibodies, Viral , Allergy and Immunology , Electrophoresis, Polyacrylamide Gel , Female , Hemagglutination Inhibition Tests , Hemagglutinin Glycoproteins, Influenza Virus , Allergy and Immunology , Humans , Influenza A Virus, H1N1 Subtype , Genetics , Allergy and Immunology , Influenza, Human , Allergy and Immunology , Virology , Rabbits , Reassortant Viruses , Genetics , Allergy and Immunology
Arq. Inst. Biol ; 83: e0202014, 2016. tab, mapas
Article in English | LILACS, VETINDEX | ID: biblio-1006845


The State of Pará comprises 26% of Brazilian Amazon region, where a large diversity of arboviruses has been described. This study sought to assess the prevalence and distribution of hemagglutination inhibition (HI) antibodies against antigens of four alphaviruses (Togaviridae: Alphavirus ) from the species: Eastern equine encephalitis (EEEV), Western equine encephalitis (WEEV), Mayaro virus (MAYV), and Mucambo virus (MUCV) in 753 serum samples of horses in Pará State, Brazil. All investigated arboviruses were detected and indicate that horses are susceptible to these alphaviruses, and show evidences of their active circulation in farm animals in the Brazilian Amazon.(AU)

O estado do Pará corresponde a 26% da Amazônia brasileira, onde uma grande diversidade de arbovírus foi descrita. Este estudo procurou avaliar a prevalência e a distribuição de anticorpos inibidores da hemaglutinação (IH) contra antígenos de quatro alfavirus (Togaviridae: Alphavirus ), das espécies: Vírus da encefalite equina do leste (EEEV), Vírus da encefalite equina do oeste (WEEV), Vírus mayaro (MAYV) e Vírus mucambo (MUCV), de 753 amostras de soro de equinos no estado do Pará, Brasil. Todos os arbovirus pesquisados foram detectados, indicando que os equinos são suscetíveis a esses Alphavirus e mostrando evidências de sua circulação ativa em animais de fazenda na Amazônia brasileira.(AU)

Animals , Arboviruses , Hemagglutination Inhibition Tests , Encephalitis Virus, Eastern Equine , Encephalitis Virus, Western Equine , Horses , Zoonoses
Article in English | WPRIM | ID: wpr-13821


The virus neutralization (VN) test was used to determine potency of the infectious bronchitis (IB) vaccine. The results of VN, hemagglutination inhibition (HI), and enzyme-linked immunosorbent assay (ELISA) were compared with those of the IBV M41. The r² values between VN and HI titers and the ELISA antibody titer were 0.8782 and 0.0336, respectively, indicating a high correlation between VN and HI, but not VN and ELISA. The Cohen's kappa coefficient between the VN titer of 2 log₁₀ and HI titer of 5 log₂ was 0.909. Our results showed that VN could be replaced with HI for testing the potency of IBV M41.

Bronchitis , Enzyme-Linked Immunosorbent Assay , Hemagglutination Inhibition Tests , Hemagglutination , Infectious bronchitis virus , Neutralization Tests , Vaccine Potency
Rev. Inst. Med. Trop. Säo Paulo ; 56(6): 487-492, Nov-Dec/2014. tab, graf
Article in English | LILACS | ID: lil-725807


The prevalence of antibodies against Equine Influenza Virus (EIV) was determined in 529 equines living on ranches in the municipality of Poconé, Pantanal area of Brazil, by means of the hemagglutination inhibition test, using subtype H3N8 as antigen. The distribution and possible association among positive animal and ranches were evaluated by the chi-square test, spatial autoregressive and multiple linear regression models. The prevalence of antibodies against EIV was estimated at 45.2% (95% CI 30.2 - 61.1%) with titers ranging from 20 to 1,280 HAU. Seropositive equines were found on 92.0% of the surveyed ranches. Equine from non-flooded ranches (66.5%) and negativity in equine infectious anemia virus (EIAV) (61.7%) were associated with antibodies against EIV. No spatial correlation was found among the ranches, but the ones located in non-flooded areas were associated with antibodies against EIV. A negative correlation was found between the prevalence of antibodies against EIV and the presence of EIAV positive animals on the ranches. The high prevalence of antibodies against EIV detected in this study suggests that the virus is circulating among the animals, and this statistical analysis indicates that the movement and aggregation of animals are factors associated to the transmission of the virus in the region.

A prevalência de anticorpos para o vírus da Influenza Equina (VIE) no município de Poconé, MT. foi determinada em 529 equídeos pela técnica de Inibição da hemaglutinação utilizando como antígeno a variante H3N8 (SP/1/85). A distribuição da positividade e possíveis associações entre os animais e as propriedades foram avaliadas pelo teste do Qui-quadrado e pelos modelos espacial autoregressivo misto e de regressão linear múltipla. A prevalência de anticorpos para o VIE no município de Poconé foi estimada em 45,2% (IC 95% 30,2 - 61,1%) com títulos variando entre 20 e 1280UIH. Das fazendas analisadas 23 (92,0%) apresentaram animais soropositivos. Animais de fazendas não alagadas (66,5%) e negativos para Anemia Infecciosa Equina (AIE) (61,7%) foram associados a soropositividade. Não houve correlação espacial entre as fazendas estudadas, entretanto aquelas localizadas nas áreas não alagadas foram associadas à infecção. Observou-se correlação negativa entre a prevalência de anticorpos para o VIE e a presença de animais positivos para AIE nas propriedades. A elevada prevalência de anticorpos para o VIE detectada neste estudo sugere circulação viral ativa entre os animais, e as análises estatísticas indicam que o trânsito e aglomeração animal são fatores associados à transmissão do vírus na região.

Animals , Female , Male , Antibodies, Viral/blood , Horse Diseases/epidemiology , /immunology , Orthomyxoviridae Infections/veterinary , Brazil/epidemiology , Horses , Hemagglutination Inhibition Tests/veterinary , Horse Diseases/diagnosis , Orthomyxoviridae Infections/diagnosis , Orthomyxoviridae Infections/epidemiology , Population Surveillance , Prevalence
Rev. Soc. Bras. Med. Trop ; 47(3): 280-286, May-Jun/2014. tab, graf
Article in English | LILACS | ID: lil-716403


Introduction Saint Louis encephalitis virus (SLEV) primarily occurs in the Americas and produces disease predominantly in humans. This study investigated the serological presence of SLEV in nonhuman primates and horses from southern Brazil. Methods From June 2004 to December 2005, sera from 133 monkeys (Alouatta caraya, n=43; Sapajus nigritus, n=64; Sapajus cay, n=26) trap-captured at the Paraná River basin region and 23 blood samples from farm horses were obtained and used for the serological detection of a panel of 19 arboviruses. All samples were analyzed in a hemagglutination inhibition (HI) assay; positive monkey samples were confirmed in a mouse neutralization test (MNT). Additionally, all blood samples were inoculated into C6/36 cell culture for viral isolation. Results Positive seroreactivity was only observed for SLEV. A prevalence of SLEV antibodies in sera was detected in Alouatta caraya (11.6%; 5/43), Sapajus nigritus (12.5%; 8/64), and S. cay (30.8%; 8/26) monkeys with the HI assay. Of the monkeys, 2.3% (1/42) of A. caraya, 6.3% 94/64) of S. nigritus, and 15.4% (4/26) of S. cay were positive for SLEV in the MNT. Additionally, SLEV antibodies were detected by HI in 39.1% (9/23) of the horses evaluated in this study. Arboviruses were not isolated from any blood sample. Conclusions These results confirmed the presence of SLEV in nonhuman primates and horses from southern Brazil. These findings most likely represent the first detection of this virus in nonhuman primates beyond the Amazon region. The detection of SLEV in animals within a geographical region distant from the Amazon basin suggests that there may be widespread and undiagnosed dissemination of this disease in Brazil. .

Animals , Mice , Encephalitis Virus, St. Louis/immunology , Encephalitis, St. Louis/veterinary , Horse Diseases/epidemiology , Monkey Diseases/epidemiology , Antibodies, Viral/blood , Brazil/epidemiology , Encephalitis, St. Louis/diagnosis , Encephalitis, St. Louis/epidemiology , Horses , Hemagglutination Inhibition Tests/veterinary , Horse Diseases/diagnosis , Horse Diseases/virology , Monkey Diseases/diagnosis , Monkey Diseases/virology , Platyrrhini , Prevalence
Biomédica (Bogotá) ; 34(2): 198-206, abr.-jun. 2014. ilus, graf, tab
Article in Spanish | LILACS | ID: lil-712402


Introducción. El diagnóstico de infección por Trypanosoma cruzi en fase crónica se hace por medio de pruebas serológicas cuya reproducibilidad no está muy documentada. Objetivo. Evaluar la reproducibilidad de las pruebas serológicas ELISA, IFI y HAI para el diagnóstico de infección por T. cruzi en mujeres embarazadas de una zona endémica de Santander. Materiales y métodos. Mediante la evaluación de la tecnología diagnóstica se determinó la reproducibilidad de las pruebas serológicas ELISA, IFI y HAI en muestras de suero y elución sanguínea, seleccionadas mediante muestreo de corte transversal y pertenecientes a mujeres embarazadas de una zona endémica para enfermedad de Chagas en Santander. Se usó el software Stata, versión 10.0, para los análisis estadísticos. La prueba con la mejor reproducibilidad se determinó por medio de la comparación de los índices kappa más altos de cada técnica. Resultados. Se evaluaron 777 sueros y elución sanguíneas. En suero, la prueba ELISA (punto de corte=0,3), la IFI (punto de corte=1/32) y la HAI (punto de corte=1/16) presentaron índices kappa mayores de 0,8 (0,98, IC 95% : 0,93-1,00; 0,98, IC 95% : 0,92-1,00 y 0,88, IC 95% : 0,74-0,97, respectivamente); no se observaron diferencias estadísticamente significativas entre las tres pruebas evaluadas (p>0,05). Para la elución sanguínea, el índice kappa estuvo por debajo de 0,8 (valor kappa más alto: 0,55, IC 95% : 0,41-0,68). Conclusiones. Las tres pruebas serológicas presentaron reproducibilidad perfecta en suero, determinada mediante el índice kappa, por lo que cualquiera de ellas sería útil para establecer el diagnóstico de infección por T. cruzi . Por su simplicidad y su costo, la prueba ELISA se recomienda como prueba de elección para los programas de tamización de esta infección.

Introduction: The diagnosis of chronic Trypanosoma cruzi infection is supported by serological tests whose reproducibility has not been well documented. Objective: To evaluate the reproducibility of the serological tests ELISA, IFAT and IHAT for the diagnosis of T. cruzi infection in pregnant women in an endemic zone in Santander. Materials and methods: Through an evaluation study of diagnostic technologies, the reproducibility of the serological tests ELISA, IFAT and IHAT was determined in serum and eluted blood from pregnant women living in an endemic area for Chagas´ disease in Santander. The samples were selected by cross sectional sampling. The software Stata ™ version 10.0 was used for statistical analysis. By means of the comparison of the highest kappa coefficient of each technique, the test with the best reproducibility was determined. Results: A total of 777 samples were tested. In serum, ELISA (cutoff point: 0.3), IFAT (cutoff point: 1/32) and IHAT (cutoff point: 1/16) had kappa coefficients greater than 0.8 (0.98, 95% CI: 0.93-1.00; 0.98, 95% CI: 0.92-1.00 and 0.88, 95% CI: 0.74-0.97, respectively); no statistically significant differences among the three tests were found (p> 0.05). For the blood eluates, kappa coefficients were below 0.8 (highest kappa: 0.55, 95% CI: 0.41-0.68). Conclusions: For the three serological tests using serum, the reproducibility determined by the kappa coefficient was perfect. Selecting any of them is useful for the diagnosis of T. cruzi infection. Given its simplicity and cost, the ELISA test is recommended for screening for this infection.

Adolescent , Adult , Female , Humans , Middle Aged , Pregnancy , Young Adult , Antibodies, Protozoan/blood , Chagas Disease/diagnosis , Endemic Diseases , Enzyme-Linked Immunosorbent Assay , Fluorescent Antibody Technique, Indirect , Hemagglutination Inhibition Tests , Pregnancy Complications, Infectious/diagnosis , Trypanosoma cruzi/immunology , Cross-Sectional Studies , Chagas Disease/epidemiology , Colombia/epidemiology , Pilot Projects , Population Surveillance , Pregnancy Complications, Infectious/epidemiology , Reproducibility of Results
Rev. Inst. Med. Trop. Säo Paulo ; 56(3): 191-195, May-Jun/2014. tab, graf
Article in English | LILACS | ID: lil-710407


Equines are susceptible to respiratory viruses such as influenza and parainfluenza. Respiratory diseases have adversely impacted economies all over the world. This study was intended to determine the presence of influenza and parainfluenza viruses in unvaccinated horses from some regions of the state of São Paulo, Brazil. Blood serum collected from 72 equines of different towns in this state was tested by hemagglutination inhibition test to detect antibodies for both viruses using the corresponding antigens. About 98.6% (71) and 97.2% (70) of the equines responded with antibody protective titers (≥ 80 HIU/25µL) H7N7 and H3N8 subtypes of influenza A viruses, respectively. All horses (72) also responded with protective titers (≥ 80) HIU/25µL against the parainfluenza virus. The difference between mean antibody titers to H7N7 and H3N8 subtypes of influenza A viruses was not statistically significant (p > 0.05). The mean titers for influenza and parainfluenza viruses, on the other hand, showed a statistically significant difference (p < 0.001). These results indicate a better antibody response from equines to parainfluenza 3 virus than to the equine influenza viruses. No statistically significant differences in the responses against H7N7 and H3N8 subtypes of influenza A and parainfluenza 3 viruses were observed according to the gender (female, male) or the age (≤ 2 to 20 years-old) groups. This study provides evidence of the concomitant presence of two subtypes of the equine influenza A (H7N7 and H3N8) viruses and the parainfluenza 3 virus in equines in Brazil. Thus, it is advisable to vaccinate equines against these respiratory viruses.

Os equinos são susceptíveis aos vírus respiratórios, como o vírus influenza, e também tem sido citado o vírus parainfluenza. Doenças respiratórias têm impactado a economia em todo mundo. Este estudo intencionou determinar a presença dos vírus influenza e parainfluenza em equinos não vacinados de certas regiões do Estado de São Paulo, Brasil. Os soros coletados de 72 equinos, de diferentes cidades deste Estado, foram submetidos ao teste de Inibição da Hemaglutinação (IH) com objetivo de detectar anticorpos contra os referidos vírus, usando antígenos correspondentes. Cerca de 98,8% (72) e 97,2% (70) desses equinos responderam com títulos protetores (≥ 80 UIH/25µL) para os subtipos H7N7 e H3N8 de vírus influenza, respectivamente. Todos equinos (72) responderam com títulos protetores (≥ 80 UIH/25µL) contra o vírus parainfluenza 3. A diferença entre as médias de anticorpos contra o vírus influenza A não foi estatisticamente significante (p > 0,05). As médias de títulos dos vírus influenza e parainfluenza, por outro lado, demonstraram diferença estatisticamente significante (p < 0,001). Esses resultados indicam melhor resposta de anticorpos pelos equinos ao vírus parainfluenza 3 do que ao vírus da influenza equina. Nenhuma diferença estatística foi observada nas respostas contra os vírus da influenza equina A (H7N7 e H3N8) e parainfluenza 3, com relação ao gênero (fêmeas e machos) e grupo etário (≤ 2 até 20 anos) nos equinos avaliados. Este estudo fornece evidência da presença concomitante dos dois subtipos vírus influenza A (H7N7 e H3N8) e do parainfluenza 3 em cavalos no Brasil. Portanto, é aconselhável a vacinação dos cavalos contra esses vírus respiratórios.

Animals , Female , Male , Horse Diseases/virology , /immunology , /immunology , Orthomyxoviridae Infections/veterinary , Age Factors , Antibodies, Viral/blood , Brazil/epidemiology , Hemagglutination Inhibition Tests , Horses , Horse Diseases/diagnosis , Horse Diseases/epidemiology , Orthomyxoviridae Infections/diagnosis , Orthomyxoviridae Infections/epidemiology
Pesqui. vet. bras ; 34(5): 462-468, May 2014. tab
Article in Portuguese | LILACS | ID: lil-714718


Este estudo descreve a primeira investigação de anticorpos para arbovírus em primatas não humanos do Novo Mundo no nordeste brasileiro. No período de março de 2008 a setembro de 2010 foram colhidos soros sanguíneos de 31 macacos-prego-galegos (Cebus flavius) de vida livre na Paraíba e de 100 macacos-prego (Cebus libidinosus) em cativeiro nos estados de Alagoas, Paraíba, Pernambuco, Piauí e Rio Grande do Norte. Para a pesquisa de anticorpos utilizou-se o teste de inibição da hemaglutinação (IH), usando antígenos de 19 diferentes tipos de arbovírus, pertencentes aos gêneros Flavivirus,Alphavirus e Bunyavirus. As amostras de soro foram testadas nas diluições de 1:20 a 1:1280. Dentre as amostras examinadas, todas as de C. flavius foram negativas e 46 por cento das de C. libidinosus em cativeiro apresentaram anticorpos para arbovírus. Foram detectados anticorpos para nove (9/19) arbovírus. Foram observadas 17 reações heterotípicas, para dois ou mais vírus, do gênero Flavivirus, e 15 para o gênero Alphavirus, com títulos variando de 1:20 a 1:1280. Quinze amostras apresentaram reação monotípica para ILHV (n=4), MAYV (n=6), SLEV (n=1), ROCV (n=2), OROV (n=1) e MUCV (n=1). Estes resultados sugerem que houve intensa circulação de arbovírus na população estudada de macacos-prego em cativeiro.

This paper describes the first investigation of arbovirus antibodies on New World non-human primates from Northeast Brazil. From March 2008 to September 2010 blood serum samples were collected from 31 wild blond capuchin monkeys (Cebus flavius) from Paraíba and 100 captive capuchin monkeys from Alagoas, Paraíba, Pernambuco, Piauí and Rio Grande do Norte. The haemagglutination-inhibition test (HI) was employed for 19 arbovirus of the Flavivirus,Alphavirus and Bunyavirus genus. Serum samples were tested from 1:20 to 1:1280 dilutions. Among the primates tested all C. flavius were negative and 46 percent C. libidinosus presented antibodies to arbovirus. Antibodies were detected for nine arbovirus (9/19). Seventeen heterotypic reactions were observed for at least two Or Flavirus and 15 for Alphavirus, at titers varying between 1:20 to 1:1280. Fifteen samples presented monotypic reaction for ILHV (n=4), MAYV (n=6), SLEV (n=1), ROCV (n=2), OROV (n=1) and MUCV (n=1). These results suggest that there was an intense arbovirus circulation in the studied population of captive capuchin monkeys.

Animals , Alphavirus/isolation & purification , Antibodies, Viral/analysis , Cebus/immunology , Cebus/virology , Flavivirus/isolation & purification , Orthobunyavirus/isolation & purification , Arboviruses/isolation & purification , Hemagglutination Inhibition Tests/veterinary
Chinese Journal of Epidemiology ; (12): 949-952, 2014.
Article in Chinese | WPRIM | ID: wpr-261592


<p><b>OBJECTIVE</b>To evaluate the safety and immunogenicity of seasonal inactivated influenza vaccine (split virion) and to analyze its cross-reactive antibody responses to H7N9 avian influenza virus.</p><p><b>METHODS</b>An open-labeled clinical trial was carried out in infants aged 6-35 months, adults aged 18-60 years and the elderly aged >60 years. After vaccinations (one dose for adults and the elderly and two doses for infants), adverse events were observed. Serum samples were obtained before vaccination and 21 days after vaccination from adults and elderly subjects. Three types of antibody against seasonal influenza virus and antibody against H7N9 avian influenza virus were tested using microhemagglutination inhibition (HI) assay. Immunogenicity of the vaccine was evaluated based on the immunogenicity criteria for adults and the elderly, set by the Committee for Medicinal Products for Human Use (CHMP) for the European Medicines Agency.</p><p><b>RESULTS</b>A total of 202 subjects (65 infants, 69 adults and 68 elderly) were enrolled and injected for at least one dose. The overall rate of adverse events was 12.4% (25/202) and most of them were under systemic reaction. No serious adverse event was reported. Pre- and post-vaccination serum samples were collected from 124 subjects (64 adults, 60 elderly). After 21 days of vaccination, the sero-conversion rate, sero-protection rate, and geometric mean titer (GMT) ratio (post-/pre-vaccination) of antibody against seasonal influenza virus were 78.1%-90.6%, 92.2%-100.0% and 7.9-41.0 among adults while 66.7%-83.3%, 86.7%-100.0% and 5.7-20.4 among the elderly, respectively. However, after vaccination, both sero-conversion rate and sero-protection rate of antibody against H7N9 avian influenza virus among adults and the elderly became zero, with GMT ratio between 1.2 and 1.4.</p><p><b>CONCLUSION</b>This trial vaccine appeared to have good safety and immunogenicity but inducing no cross-reactive antibody response to H7N9 avian influenza virus.</p>

Adult , Aged , Aged, 80 and over , Antibodies, Viral , Blood , Antibody Formation , Child, Preschool , Cross Reactions , Hemagglutination Inhibition Tests , Humans , Infant , Influenza A Virus, H7N9 Subtype , Influenza Vaccines , Allergy and Immunology , Therapeutic Uses , Middle Aged , Vaccines, Inactivated , Allergy and Immunology , Therapeutic Uses , Young Adult
Article in English | WPRIM | ID: wpr-632612


BACKGROUND: Dengue is a major health problem. The lack of data on the usefulness of rapid diagnostic tests for early detection of dengue has generated interest in determining their validity. OBJECTIVES: This research aimed to determine the validity of dengue IgA antibody versus NS1 antigen test as rapid diagnostic tests for early detection of dengue using Hemagglutination Inhibition test (HI) as standard reference. METHODOLOGY: This study included 51 pediatric patients being evaluated for dengue in a private hospital from March 01, 2012 to October 30, 2012. Paired serum samples from patients suspected of dengue and had fever of not more than seven days were examined. Initial blood samples were collected on the first day of consult and tested for dengue IgA antibody, dengue NS1 antigen, and dengue HI tests. Second blood samples for HI were collected seven days after the initial extraction RESULTS: The 51 serum samples used in this study came from 29 males and 22 females. From these samples, sensitivity of dengue IgA antibody was 80% with 95% CI (70-90) while specificity was at 50% with 95% CI(34-64) while dengue NS1 antigen which showed sensitivity of 27% with 95% CI (15-39) and specificity of 67% with 95% CI (54-86). IgA rapid test demonstrated 71% positivity in detecting acute primary dengue infection and 82% for acute secondary infection. NS1 detected 43% of primary infection and 24% of secondary infection. CONCLUSION: Dengue IgA antibody rapid test was more sensitive than NS1 antigen test for early diagnosis of dengue and had better performance in detecting primary and secondary dengue.

Humans , Male , Female , Adolescent , Child , Immunoglobulin A , Antigens , Hemagglutination Inhibition Tests
Rev. Soc. Bras. Med. Trop ; 46(6): 684-690, Nov-Dec/2013. tab, graf
Article in English | LILACS | ID: lil-698054


Introduction A sero-epidemiological survey was undertaken to detect the circulation of arboviruses in free-living non-human primates. Methods Blood samples were obtained from 16 non-human primates (13 Sapajus spp. and three Alouatta caraya) that were captured using terrestrial traps and anesthetic darts in woodland regions in the municipalities of Campo Grande, Aquidauana, Jardim, Miranda and Corumbá in the State of Mato Grosso do Sul, Brazil. The samples were sent to the Instituto Evandro Chagas (IEC) in Ananindeua, Pará, Brazil, to detect antibodies against 19 species of arboviruses using a hemagglutination inhibition test (HI). Results Of the 16 primates investigated in the present study, five (31.2%) were serologically positive for an arbovirus. Of these five, two (12.5%) exhibited antibodies to the Flavivirus genus, one (6.2%) exhibited a monotypic reaction to Cacipacoré virus, one (6.2%) was associated with Mayaro virus, and one (6.2%) was positive for Oropouche virus. Conclusions Based on the positive serology observed in the present study, it was possible to conclude that arboviruses circulate among free-living primates. The viruses in the areas studied might have been introduced by infected humans or by primates from endemic or enzootic areas. Studies of this nature, as well as efficient and continuous surveillance programs, are needed to monitor viral activities in endemic and enzootic regions. .

Animals , Female , Male , Alouatta/virology , Arboviruses/isolation & purification , Carrier State/veterinary , Antibodies, Viral/blood , Arboviruses/immunology , Brazil/epidemiology , Carrier State/virology , Hemagglutination Inhibition Tests , Seroepidemiologic Studies
Article in English | WPRIM | ID: wpr-92902


A recombinant hemagglutinin-neuraminidase (rHN) protein from Newcastle disease virus (NDV) with hemagglutination (HA) activity was expressed in Spodoptera frugiperda cells using a baculovirus expression system. The rHN protein extracted from infected cells was used as an antigen in a hemagglutination inhibition (HI) test for the detection and titration of NDV-specific antibodies present in chicken sera. The rHN antigen produced high HA titers of 2(13) per 25 microL, which were similar to those of the NDV antigen produced using chicken eggs, and it remained stable without significant loss of the HA activity for at least 12 weeks at 4degrees C. The rHN-based HI assay specifically detected NDV antibodies, but not the sera of other avian pathogens, with a specificity and sensitivity of 100% and 98.0%, respectively, in known positive and negative chicken sera (n = 430). Compared with an NDV-based HI assay, the rHN-based HI assay had a relative sensitivity and specificity of 96.1% and 95.5%, respectively, when applied to field chicken sera. The HI titers of the rHN-based HI assay were highly correlated with those in an NDV-based HI assay (r = 0.927). Overall, these results indicate that rHN protein provides a useful alternative to NDV antigen in HI assays.

Animals , Antibodies, Viral/blood , Antigens, Viral , Baculoviridae/genetics , Chickens , HN Protein , Hemagglutination Inhibition Tests/methods , Newcastle Disease/diagnosis , Newcastle disease virus/genetics , Poultry Diseases/diagnosis , Recombinant Proteins , Sf9 Cells , Spodoptera
Article in English | WPRIM | ID: wpr-78971


PURPOSE: Although influenza is regarded as a major cause of morbidity and mortality in immunocompromised patients, vaccine coverage remains poor. We evaluated the immunogenicity of influenza vaccines in colorectal cancer patients. MATERIALS AND METHODS: In this study, 40 colorectal cancer patients who received an influenza vaccine at the Korea Cancer Center Hospital during the 2009-2010 and 2010-2011 influenza seasons were analyzed. The blood samples were collected at prevaccination and 30 days post vaccination, and antibody titers were measured using the hemagglutination-inhibition tests. RESULTS: In the 2009-2011 season, the seroprotection rate for H1N1 (94.7%) was significantly higher than that for H3N2 (42.1%) and B (47.3%). The seroconversion rate was 52.6%, 26.3%, and 36.8% for H1N1, H3N2, and B, respectively. Fold increase of geometric mean titer (MFI) was 3.86, 1.49, and 3.33 for H1N1, H3N2, and B, respectively. In the 2010-2011 season, the seroprotection rate for H1N1 (57.1%) was significantly higher than that for H3N2 (52.4%) and B (38.1%). The seroconversion rate was 52.4%, 47.6% and 33.3% for H1N1, H3N2, and B, respectively. MFI was 12.29, 3.62 and 4.27 for H1N1, H3N2, and B, respectively. CONCLUSION: Our study cohort showed an acceptable immune response to an influenza vaccine without significant adverse effects, supporting the recommendation for annual influenza vaccination in colorectal cancer patients.

Cohort Studies , Colorectal Neoplasms , Hemagglutination Inhibition Tests , Humans , Immunocompromised Host , Influenza Vaccines , Influenza, Human , Korea , Mortality , Seasons , Vaccination
Article in English | WPRIM | ID: wpr-25347


We aimed to compare the immune response induced by natural infection with 2009 pandemic influenza A/H1N1 (pH1N1) virus and by monovalent pH1N1 vaccination in children and adolescents. This cross-sectional clinical study was conducted at 3 hospitals in Korea from February to May 2010. A total of 266 healthy subjects aged from 6 months to 18 yr were tested for the presence of the antibody against pH1N1 using hemagglutination inhibition (HI) test. Information about pH1N1 vaccination and laboratory-confirmed pH1N1 infection history was obtained. The overall rate of HI titers of > or = 1:40 against pH1N1 was 38.7%, and the geometric mean titer (GMT) was 20.5. Immunogenicity of pH1N1 vaccination only was reflected by a 41.1% of seroprotection rate and a GMT of 22.5. Immunogenicity of natural infection only was reflected by a 61.0% of seroprotection rate and a GMT of 40.0. GMT was significantly higher in the subjects of natural infection group than in the subjects of pH1N1 vaccination group (P < 0.001). The immune responses induced by natural pH1N1 infection exceed those induced by pH1N1 vaccinations.

Adolescent , Antibodies, Neutralizing/blood , Antibody Formation , Child , Child, Preschool , Cross-Sectional Studies , Hemagglutination Inhibition Tests , Humans , Infant , Influenza A Virus, H1N1 Subtype/immunology , Influenza, Human/epidemiology , Pandemics , Vaccination
Rev. Inst. Med. Trop. Säo Paulo ; 54(6): 311-314, Nov.-Dec. 2012. ilus, tab
Article in English | LILACS, SES-SP | ID: lil-656265


In 1970, searching for the interspecies transmission of influenza viruses led to the first study on influenza viruses in domestic animals. Birds and mammals, including human beings, are their natural hosts; however, other animals may also play a role in the virus epidemiology. The objective was to investigate the incidence of influenza viruses in adult dogs raised in rural (9, 19.56%) and urban (37, 80.43%) areas in the state of São Paulo, Brazil. Dog serum samples were examined for antibodies to influenza viruses by the hemagglutination inhibition (HI) test using the corresponding antigens from the circulating viruses in Brazil. Dogs from rural areas presented antibodies to influenza A H3N2, and influenza A H7N7 and H3N8. In rural areas, dog sera displayed mean titers as 94.37, 227.88, 168.14, 189.62 HIU/25 µL for subtypes H1N1, H3N2, H7N7, H3N8, respectively. About 84% and 92% of dogs from urban areas exhibited antibodies to human influenza A H1N1 and H3N2, respectively, with statistical difference at p < 0.05 between the mean titers of antibodies to H1N1 and H3N2. About 92% and 100% were positive for H7N7 and H3N8, respectively. In dogs from urban areas, the mean titers of antibodies against influenza A H1N1, H3N2, H7N7 and H3N8, were 213.96, 179.42, 231.76, 231.35 HIU/25 µL respectively. The difference among them was not statistically significant at p > 0.05. In conclusion, these dogs were positive for both human and equine influenza viruses. The present study suggests the first evidence that influenza viruses circulate among dogs in Brazil.

A transmissão interespecífica do vírus influenza é relatada em estudo sobre influenza com animais domésticos desde 1970. Pássaros e mamíferos, incluindo o homem, são seus hospedeiros naturais, porém outros animais podem participar da sua epidemiologia. Foi investigada a incidência do vírus influenza em cães adultos criados em zonas rural (9, 19,56%) e urbana (37, 80,43%), do Estado de São Paulo. Os soros dos cães foram examinados pelo teste de inibição da hemaglutinação (IH), usando antígeno dos vírus influenza circulantes no Brasil. Nos cães rurais foram detectados títulos médios de 94,37, 227,88, 168,14 e 189,62 UIH/25 mL (unidades inibidoras de hemaglutinação/25 mL) para os subtipos H1N1, H3N2, H7N7, H3N8 de vírus influenza A, respectivamente, com diferenças estatisticamente significativas (p<0,05) entre as médias de títulos de anticorpos contra H1N1 e H3N2. Cerca de 84% e 92% dos cães urbanos responderam aos vírus influenza A humano H1N1 e H3N2, respectivamente e destes 92% e 100% foram positivos para os vírus eqüinos H7N7 e H3N8, respectivamente. Para esses cães as médias de títulos de anticorpos para os vírus influenza A H1N1, H3N2, H7N7 e H3N8 foram 213,96, 179,42, 231,76 e 231,35UIH/25 mL, respectivamente. As diferenças entre as médias não foram estatisticamente significativas (p>0,05). Conclui-se que os cães apresentaram positividade para ambos vírus influenza humano e equino. O presente estudo sugere, pela primeira vez, evidências de que há circulação do vírus influenza em cães, no Brasil.

Animals , Dogs , Antibodies, Viral/blood , Dog Diseases/virology , Orthomyxoviridae Infections/veterinary , Orthomyxoviridae/immunology , Brazil , Dog Diseases/diagnosis , Enzyme-Linked Immunosorbent Assay , Hemagglutination Inhibition Tests , Incidence , Influenza A Virus, H1N1 Subtype/immunology , /immunology , /immunology , /immunology , Orthomyxoviridae Infections/diagnosis , Orthomyxoviridae/classification , Rural Population , Urban Population