Global epidemiology of Equine Influenza viruses: "A possible emerging zoonotic threat in future" an extensive systematic review with evidence / Epidemiologia global dos vírus da Gripe Equina: "Uma possível ameaça zoonótica emergente no futuro" uma extensa revisão sistemática com evidências

There are different opinions around the World regarding the zoonotic capability of H3N8 equine influenza viruses. In this report, we have tried to summarize the findings of different research and review articles from Chinese, English, and Mongolian Scientific Literature reporting the evidence for equine influenza virus infections in human beings. Different search engines i.e. CNKI, PubMed, ProQuest, Chongqing Database, Mongol Med, and Web of Knowledge yielded 926 articles, of which 32 articles met the inclusion criteria for this review. Analyzing the epidemiological and Phylogenetic data from these articles, we found a considerable experimental and observational evidence of H3N8 equine influenza viruses infecting human being in different parts of the World in the past. Recently published articles from Pakistan and China have highlighted the emerging threat and capability of equine influenza viruses for an epidemic in human beings in future. In this review article we have summarized the salient scientific reports published on the epidemiology of equine influenza viruses and their zoonotic aspect. Additionally, several recent developments in the start of 21st century, including the transmission and establishment of equine influenza viruses in different animal species i.e. camels and dogs, and presumed encephalopathy associated to influenza viruses in horses, have documented the unpredictable nature of equine influenza viruses. In sum up, several reports has highlighted the unpredictable nature of H3N8 EIVs highlighting the need of continuous surveillance for H3N8 in equines and humans in contact with them for novel and threatening mutations.

Existem diferentes opiniões em todo o mundo a respeito da capacidade zoonótica dos vírus da influenza equina H3N8. Neste relatório, tentamos resumir os resultados de diferentes pesquisas e artigos de revisão da literatura científica chinesa, inglesa e mongol relatando as evidências de infecções pelo vírus da influenza equina em seres humanos. Diferentes mecanismos de busca, como CNKI, PubMed, ProQuest, Chongqing Database, Mongol Med e Web of Knowledge geraram 926 artigos, dos quais 32 atenderam aos critérios de inclusão para esta revisão. Analisando os dados epidemiológicos e filogenéticos desses artigos, encontramos uma considerável evidência experimental e observacional de vírus da influenza equina H3N8 infectando seres humanos em diferentes partes do mundo no passado. Artigos publicados recentemente no Paquistão e na China destacaram a ameaça emergente e a capacidade dos vírus da influenza equina para uma epidemia em seres humanos no futuro. Neste artigo de revisão, resumimos os relatórios científicos relevantes publicados sobre a epidemiologia dos vírus da influenza equina e seu aspecto zoonótico. Além disso, vários desenvolvimentos recentes no início do século 21, incluindo a transmissão e estabelecimento de vírus da influenza equina em diferentes espécies animais, ou seja, camelos e cães, e presumida encefalopatia associada aos vírus da influenza em cavalos, documentaram a natureza imprevisível dos vírus da influenza equina. Em suma, vários relatórios destacaram a natureza imprevisível de H3N8 EIVs destacando a necessidade de vigilância contínua para H3N8 em equinos e humanos em contato com eles para novas mutações ameaçadoras.

Effect of coinfection with influenza virus and bacteria on host damage / Efecto de la coinfección por virus de la influenza y bacterias en el daño al hospedero

Abstract Background: Influenza virus infection is often complicated by a bacterial infection, with this coinfection causing severe pneumonia. If not timely treated, the disease can cause death. Objective: To demonstrate, in animal models, that coinfection with influenza virus and bacteria that affect the respiratory tract causes multisystemic damage. Method: Six groups of mice were formed: a control group, one infected with the influenza virus, two infected with bacteria: Haemophilus influenzae and Streptococcus pneumoniae, respectively; and two co-infected with influenza virus and Haemophilus influenzae or Streptococcus pneumoniae, respectively. Results: Of the six groups of mice, only the group co-infected with influenza virus and Streptococcus pneumoniae showed damage to thoracic and abdominal organs. A decrease in serum cytokine levels was found in all study groups, which was more pronounced in the co-infected mice. Conclusions: The groups of mice infected with Streptococcus pneumoniae or influenza virus alone showed no damage, which indicates that coexistence of these infections caused the damage in the group of co-infected mice.

Resumen Antecedentes: La infección por el virus de la influenza con frecuencia se complica con una infección bacteriana, coinfección que provoca cuadros graves de neumonía, la cual puede ocasionar la muerte si no es tratada en forma oportuna. Objetivo: Demostrar en modelos animales que la coinfección por el virus de la influenza y bacterias que afectan el tracto respiratorio ocasiona daño multisistémico. Método: Se formaron seis grupos de ratones: un grupo control, uno infectado de virus de la influenza, dos infectados de bacterias: Haemophilus influenzae y Streptococcus pneumoniae, respectivamente; y dos coinfectados de virus de la influenza y Haemophilus influenzae y Streptococcus pneumoniae, respectivamente. Resultados: De los seis grupos de ratones, solo en el grupo coinfectado de virus de la influenza y Streptococcus pneumoniae se observó daño en órganos torácicos y abdominales. En todos los grupos se encontró disminución de los niveles séricos de las citocinas, mayor en los ratones coinfectados. Conclusiones: Los grupos de ratones infectados solo de Streptococcus pneumoniae o el virus de la influenza no presentaron daños, lo cual indica que la coexistencia de estas infecciones fue la que ocasionó el daño en el grupo de ratones coinfectados.

Infectious diseases dynamics in growing/finishing pigs in Southern Brazil (2005-2016) / Dinâmica de ocorrência das doenças infecciosas em suínos nas fases de crescimento e terminação no sul do Brasil (2005-2016)

This study aimed to determine the frequency and distribution of infectious diseases diagnosed through necropsy examination and histopathological analysis in growing/finishing pigs along 12 years (2005-2016) in Southern Brazil. We evaluated 1906 anatomopathological exams of pigs at growing/finishing phases, of which the infectious diseases corresponded to 75.6% of the cases (1,441/1,906). Porcine circovirus type 2 (PCV2) infections were the most frequent, accounting for 51.3% of the cases (739/1,441) with a higher frequency from 2005 to 2007, characterizing an epidemic distribution, with a gradual decline after 2008. Infectious diseases affecting the respiratory system were the second major cause with 30.1% of the cases. Among these, necrotizing bronchiolitis caused by swine Influenza (15.1%, 218/1,441) and bacterial pneumonia (15%, 216/1,441) were the main conditions. Influenza was mostly diagnosed from 2010 to 2013, accounting for 43.1% (167/387) of the cases. After this period, both respiratory infectious diseases were endemic. Digestive system infectious diseases accounted for 10.5% of the diagnoses (151/1,441), with the following main conditions: Salmonella spp. enterocolitis (43.7%, 66/151), Lawsonia spp. proliferative enteropathy (41.7%, 63/151), and Brachyspira spp. colitis (14.6%, 22/151). The latter had a higher incidence from 2012 to 2014 with all cases detected in this period. Polyserositis and bacterial meningitis represented, respectively, 5.8% (84/1,441) and 2.3% (33/1,441) of the cases diagnosed, with a constant endemic character.(AU)

O objetivo deste estudo consistiu em determinar a frequência e a distribuição das doenças infecciosas diagnosticadas através de exame de necropsia e análise histopatológica em suínos nas fases de crescimento/terminação ao longo de 12 anos (2005-2016) no sul do Brasil. Foram avaliados 1906 laudos anatomopatológicos de suínos nas fases de crescimento/terminação, dos quais as doenças infecciosas corresponderam a 75,6% (1441/1906) do total. As infecções por circovírus suíno tipo 2 (PCV2) foram as mais frequentes, contabilizando 51,3% (739/1441) dos casos, com uma alta frequência de 2005 a 2007 caracterizando uma distribuição epidêmica neste período, e um declínio gradual após o ano de 2008. A segunda principal causa incluiu as doenças infecciosas que afetam o sistema respiratório (30,1% dos casos). Dentre essas, destacaram-se a influenza suína (15,1%; 218/1441) e pneumonias bacterianas (15%; 216/1441). O diagnóstico de influenza apresentou uma frequência elevada de 2010 a 2013, totalizando 43,1% (167/387) dos casos. Após este período, ambas doenças infecciosas respiratórias exibiram caráter endêmico. As doenças infecciosas do sistema digestório totalizaram 10,5% (151/1441) dos diagnósticos, com as seguintes principais condições: enterocolite por Salmonella spp. (43,7%; 66/151), enteropatia proliferativa por Lawsonia spp. (41,7%; 63/151) e colite por Brachyspira spp. (14,6%; 22/151). A colite por Brachyspira spp. apresentou uma alta incidência de 2012 a 2014 com todos os casos detectados no período. As polisserosites e meningites bacterianas representaram 5,8% (84/1441) e 2,3% (33/1441) dos casos diagnosticados, respectivamente, com um caráter endêmico constante.(AU)

Conocimientos sobre enfermedades tipo influenza en estudiantes de Medicina de la Universidad de Guayaquil, Ecuador / Knowledge about influenza-like illnesses in medical students at Guayaquil University, Ecuador

RESUMEN Fundamento: las enfermedades tipo influenza son de fácil contagio y sus vías de transmisión difíciles de controlar si no son tratadas adecuadamente. Objetivo: determinar los conocimientos que poseen los estudiantes de pregrado y posgrado de la Facultad de Ciencias Médicas de la Universidad de Guayaquil sobre las enfermedades tipo influenza. Métodos: se realizó un estudio descriptivo transversal durante el mes de febrero de 2018. Se utilizaron métodos teóricos: análisis-síntesis e inducción-deducción, y empíricos: la encuesta en forma de cuestionario para indagar sobre el conocimiento de los estudiantes sobre la influenza. Resultados: la totalidad de ellos refirió poseer conocimientos sobre el tema. El 96,32 % de los de pregrado identificaron como más frecuentes la transmisión de tipo viral y el contagio por contacto con persona enferma; mientras en posgrado el 100 % expresó conocimientos al respecto; la complicación habitual más señalada fue la automedicación referida por el 72 % en pregrado y en el posgrado por el 57 %. En relación con las medidas preventivas, manifestaron conocerlas el 87 % y 89 % en el pregrado y posgrado respectivamente. Conclusiones: se comprobó que el grado de conocimientos sobre las enfermedades tipo influenza en cuanto a transmisión, etiología, acciones de protección y medidas preventivas en estos estudiantes de la Facultad de Ciencias Médicas de la Universidad de Guayaquil es aceptable, pero aún persisten algunas carencias identificadas en el estudio realizado.

ABSTRACT Background: influenza is an easily transmitted disease and its way of transmission is difficult to control if it is not properly treated. Objective: to determine the knowledge undergraduate and graduate students have on influenza-like disease at Guayaquil University Medical Sciences Faculty. Methods: a cross-sectional descriptive study was carried out at Guayaquil University Medical Sciences Faculty, during the month of February 2018. Theoretical methods were used: analysis-synthesis and induction-deduction, and empirical methods: the survey in the form of a questionnaire to inquire about students' knowledge on influenza. Results: all the students reported having knowledge on influenza. 96,32 % of the undergraduates identified the transmission of viral type by contact with the sick person as more frequent; in postgraduate studies 100 % expressed knowledge in this regard; the most common complication was self-medication referred by 72 % of undergraduate students in 72 % and in postgraduate students by 57 %. In relation to preventive measures, 87 % and 89 % expressed knowledge in undergraduate and postgraduate respectively. Conclusions: it was found that the degree of knowledge on the influenza-like disease in terms of transmission, etiology, protective actions and preventive measures in these students at Guayaquil University Medical Sciences Faculty is acceptable. There are still some shortcomings identified in the study carried out.

Análisis de las Campañas de Vacunación Antigripal destinadas al personal de salud del HIBA: período 2016-2018 / Analysis of Influenza Vaccination Campaigns for HIBA health personnel: 2016-2018 period

Introducción: la vacunación antigripal es la forma más eficaz para prevenir la enfermedad por virus Influenza y sus complicaciones. La cobertura en los profesionales sanitarios es un indicador de calidad hospitalaria. Material y métodos: estudio descriptivo de corte transversal. A partir de registros vacunales, se calculó la cobertura para las campañas 2013 a 2018. Se compararon las coberturas por trienios. Se describieron características generales de las campañas de 2016 a 2018. Resultados: en 2016 se alcanzó la mayor tasa del período (59,79%, IC 95%:58,75-60,81); en 2017, la menor (34,46%, IC 95%:33,48-35,46). La campaña 2018 obtuvo una cobertura de 54,90% (IC 95%: 53,88-55,92) y se inició más tempranamente que otras. Al comparar las tasas trienales del período se observó una diferencia de proporción de -1,3% (IC 95%: -2.84-0.24). Durante los tres últimos años, el personal vacunado correspondió mayormente al sexo femenino, a la Sede Central y tenía relación contractual directa. Las mayores coberturas específicas correspondieron a la sede de San Justo y a los profesionales de enfermería. El puesto ambulante fue el que aplicó más vacunas. Conclusión: si bien hubo variaciones en las coberturas alcanzadas a lo largo de los años, siendo la del año 2016 la más elevada y la del año 2017 la más baja, no se observaron diferencias estadísticamente significativas en las coberturas alcanzadas al comparar trienios. Resulta necesario continuar realizando intervenciones adaptadas al contexto local que permitan alcanzar los objetivos de cobertura esperados. Discusión: se reconocieron varios obstáculos para alcanzar las coberturas esperadas. La educación al personal de salud, la evaluación sistematizada de los ESAVI (Eventos supuestamente atribuibles a vacunación e inmunización) y la descripción de los elementos que facilitaron las coberturas específicas elevadas de algunas subpoblaciones podrían contribuir para mejorar los resultados. (AU)

Introduction: influenza vaccination is the most effective way to prevent influenza virus disease and its complications. Coverage in health professionals measurement is an indicator of hospital quality. Material and methods: descriptive cross-sectional study. From vaccination records, the coverage was calculated for the 2013 to 2018 campaigns. The coverage for three years was compared. General characteristics of the campaigns from 2016 to 2018 were described. Results: in 2016, the highest was achieved during the period (59.79%, IC 95%: 58.75 -60.81). In 2017, the lowest (34.46%, IC 95%: 33.48-35,46). The 2018 campaign achieved a coverage of 54.90% (IC 95%: 53.88-55.92) and started earlier than others. When comparing the triennial rates of the period, a difference of proportion of -1.3% was observed (IC 95%: -2.84-0.24). During the last three years, the vaccinated staff corresponded mostly to the female sex, to the headquarters and had a direct contractual relationship. The largest specific coverage corresponded to the San Justo headquarters and to nursing professionals. The ambulatory position was the post that applied the most vaccines. Conclusion: although there were variations in the coverage achieved over the years, with 2016 being the highest and 2017 being the lowest, there were no statistically significant differences in the coverage achieved when comparing trienniums. It is necessary to continue carrying out interventions adapted to the local context to achieve the expected coverage objectives. Discussion: several obstacles were recognized to reach the expected coverage. The education of health personnel, the systematic evaluation of the ESAVIs and the description of the elements that facilitated the high specific coverage of some subpopulations could contribute to improve the results. (AU)

Evolution of equine influenza viruses (H3N8) during a Brazilian outbreak, 2015

Abstract Equine influenza is one of the major respiratory infectious diseases in horses. An equine influenza virus outbreak was identified in vaccinated and unvaccinated horses in a veterinary school hospital in São Paulo, SP, Brazil, in September 2015. The twelve equine influenza viruses isolated belonged to Florida Clade 1. The hemagglutinin and neuraminidase amino acid sequences were compared with the recent isolates from North and South America and the World Organisation for Animal Health recommended Florida Clade 1 vaccine strain. The hemagglutinin amino acid sequences had nine substitutions, compared with the vaccine strain. Two of them were in antigenic site A (A138S and G142R), one in antigenic site E (R62K) and another not in antigenic site (K304E). The four substitutions changed the hydrophobicity of hemagglutinin. Three distinct genetic variants were identified during the outbreak. Eleven variants were found in four quasispecies, which suggests the equine influenza virus evolved during the outbreak. The use of an out of date vaccine strain or updated vaccines without the production of protective antibody titers might be the major contributing factors on virus dissemination during this outbreak.

Detección serológica de Brucella suis, virus de influenza y virus de la enfermedad de Aujeszky en criaderos porcinos familiares de menos de 100 madres en Argentina / Serological detection of Brucella suis, influenza virus and Aujeszky's disease virus in backyard and small swine holders in Argentina

Los criaderos porcinos de menos de 100 madres representan más del 99% de los de todo el país; sin embargo, existen escasos reportes sobre su situación sanitaria y productiva. Se recabó información productiva y se tomaron muestras para detectar anticuerpos contra Brucella suis (Bs), virus de la enfermedad de Aujeszky (VA) y virus de influenza (VI) en 68 establecimientos de menos de 100 madres ubicados en la región norte, centro y sur del país. El 80% de los establecimientos fueron positivos al VI H1 pandémico 2009, el 11% al H3 clúster 2, mientras que el 11,7% presentó anticuerpos contra el VA y el 6% contra Bs. Ninguno de los productores conocía los factores de riesgo para la transmisión de enfermedades del cerdo al humano. El 47% compra sus reproductores a pares o en ferias. En lo que respecta a normas de bioseguridad, solo el 16% de los establecimientos tenía cerco perimetral y el 37% de las granjas contaba con asesoramiento veterinario. Los resultados de este estudio demuestran que la caracterización productiva y el relevamiento sanitario son de suma importancia para mejorar la productividad y reducir el riesgo de transmisión de enfermedades. El conocimiento de la situación sanitaria y de los factores de riesgo es necesario para conseguir un mejor control y la erradicación de enfermedades en sistemas de baja tecnificación. Se deberían llevar a cabo estudios más representativos a nivel país para detectar los agentes circulantes y, sobre la base de esta información, implementar medidas de prevención y control.

Farmers raising less than 100 sows represent more than 99% of swine producers in Argentina, although little is known about their sanitary status and productive characteristics in the country. Sanitary and productive information was obtained. Furthermore, samples for serological studies were taken to detect antibodies against Brucella suis (Bs), Aujeszky's disease virus (AV) and influenza virus (IV) in 68 backyard and small producers with less than 100 sows located in the north, central and south regions of Argentina. Antibodies against H1 pandemic were detected in 80% of the farms while 11%, 11.7% and 6.0% of the producers were positive to influenza H3 cluster 2, AV and Bs, respectively. None of the producers was aware of the risk factors concerning the transmission of diseases from pigs to humans. A percentage of 47% of them buy pigs for breeding from other farmers and markets. With regard to biosecurity measures, only 16% of the farms had perimeter fences. The results of this study demonstrate that productive characterization and disease surveys are important to improve productivity and to reduce the risk of disease transmission among animals and humans. The study of sanitary status and risk factors is necessary for better control and eradication of diseases in backyard or small producers. More representative studies at country level should be carried out to detect the pathogensthat circulate and, with this knowledge, to implement prevention and control measures.

Prevalence of attibodies against influenza viru in non-vaccinated equines fromm the Brazilian pantaall / Prevalência de anticorpos contra o vírus da Influenza em equinos não vacinados do Pantanal Brasileiro

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.

The rapid and sustained responses of dendritic cells to influenza virus infection in a non-human primate model

Dendritic cells (DCs) are readily infected by influenza viruses and play a crucial role in regulating host innate and adaptive immune responses to viral infection. The aims of this study are to characterize the dynamic changes in the numbers and maturation status of dendritic cells present in the lung and lung-associated lymph nodes (LALNs) in the model of a non-human primate (NHP) infected by influenza A virus (IAV). Cynomolgus macaques were infected with influenza A virus (H3N2) via bronchoscopy. Flow cytometry was used to analyze the DC numbers, maturation status and subsets during the time of acute infection (days 1, 2, 3, 4, 7) and the resolution phase (day 30). A dramatic increase in the numbers of influenza A virus-infected CD11c+CD14- myeloid dendritic cells (mDCs) and CD11c-CD123+ plasmacytoid dendritic cells (pDCs) were observed from day 1 to day 4 and peak up from day 7 post-infection. In lung and lung-associated lymph nodes, the numbers and maturation status of myeloid dendritic cells and plasmacytoid dendritic cells increased more slowly than those in the lung tissues. On day 30 post-infection, influenza A virus challenge increased the number of myeloid dendritic cells, but not plasmacytoid dendritic cells, compared with baseline. These findings indicate that dendritic cells are susceptible to influenza A virus infection, with the likely purpose of increasing mature myeloid dendritic cells numbers in the lung and lung and lung-associated lymph nodes, which provides important new insights into the regulation of dendritic cells in a non-human primate model.

Presence of resiiratory viruses in equines in Brazil / Presença de vírus respiratórios em equinos do Brasil

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.

Influenza A virus infection of healthy piglets in an abattoir in Brazil: animal-human interface and risk for interspecies transmission

Asymptomatic influenza virus infections in pigs are frequent and the lack of measures for controlling viral spread facilitates the circulation of different virus strains between pigs. The goal of this study was to demonstrate the circulation of influenza A virus strains among asymptomatic piglets in an abattoir in Brazil and discuss the potential public health impacts. Tracheal samples (n = 330) were collected from asymptomatic animals by a veterinarian that also performed visual lung tissue examinations. No slaughtered animals presented with any noticeable macroscopic signs of influenza infection following examination of lung tissues. Samples were then analysed by reverse transcription-polymerase chain reaction that resulted in the identification of 30 (9%) influenza A positive samples. The presence of asymptomatic pig infections suggested that these animals could facilitate virus dissemination and act as a source of infection for the herd, thereby enabling the emergence of influenza outbreaks associated with significant economic losses. Furthermore, the continuous exposure of the farm and abattoir workers to the virus increases the risk for interspecies transmission. Monitoring measures of swine influenza virus infections and vaccination and monitoring of employees for influenza infection should also be considered. In addition regulatory agencies should consider the public health ramifications regarding the potential zoonotic viral transmission between humans and pigs.

Influenza viruses in adult dogs raised in rural and urban areas in the state of São Paulo, Brazil / Incidência do vírus influenza em cães adultos criados em áreas rural e urbana do estado de São Paulo, Brasil

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.

VaxcineTM: an oil-based adjuvant for influenza vaccines

Vaccination is the method of choice for the prevention of influenza infection. However, the quantity of the antigen available, especially in the case of pandemics, often fails to meet the global demand. However, improved adjuvants can overcome this problem. Preliminary results obtained in this study revealed that one year after a single subcutaneous immunisation with influenza A H3N2 virus in an oil-based carrier, VaxcineTM, outbreed mice produced a high immunoglobulin G response that lasted for up to one year and exhibited less variation in titre compared with the response of the control group treated with alum. The haemagglutination-inhibition titres induced by VaxcineTM were also higher than those generated by alum. These data indicate that VaxcineTM is a good adjuvant candidate for seasonal influenza vaccines.

Diversidade genética dos vírus influenza A detectados em crianças de São Paulo / Genetic diversity of influenza virus A detected in children of São Paulo

Os vírus Influenza A infectam um largo espectro de hospedeiros e causam epidemias anuais. São vírus com alta variabilidade genética e RNA segmentado, que podem sofrer rearranjos entre os genes de diferentes vírus. Em 2006, foram analisadas 521 amostras de crianças menores de 5 anos atendidas no HU-USP e 25 foram positivas para Influenza A, sendo H3N2 o mais prevalente (68%). Cinco genes de 18 amostras foram seqüenciados e obtivemos 13 sequencias de HA, 12 da NP, 12 de NA, 14 da M e 10 da NS. Verificou-se a presença de várias mutações, especialmente na HA e NA, que favoreceram a substituição da cepa vacinal naquele ano. Todas as amostras H3N2 apresentaram sítios de resistências aos inibidores da M2. Diferentes linhagens circularam no mesmo ano, tanto de H1 como de H3, favorecendo rearranjos entre elas. Foram verificados, também rearranjos envolvendo os genes da HA e NP, indicando o complexo mecanismo de evolução desses vírus e enfatizando a necessidade de monitoramento da circulação e caracterização de seus genes.

Influenza A virus infects a wide range of hosts and cause annual outbreaks. RNA segmented virus has high genetic variability and may have rearrangements between the genes of different viruses. In 2006, 521 samples of children younger than 5 years were analyzed and 25 tested positive for Influenza A virus, of which the subtype H3N2 is the most prevalent (68%). Five genes of 18 samples were sequenced and 13 sequences of HA, 12 of NP, 14 of M and 10 of NS obtained were. The presence of this several mutations, especially in the HA and NA genes probably helped the replacement of the vaccine strain in that year. All H3N2 subtype samples showed points of resistance to M2 inhibitors. The phylogenetic analysis revealed the circulation of different lineages in the same year, for both H1 and H3, and the presence of two rearrangements involving the HA and NP genes. These results indicate the influence of rearrangements in the evolution of the virus and emphasize the need for monitoring of circulation and characterization of genes.

Prevalencia serológica del virus de influenza A en cerdos en Argentina durante la temporada 2002: evaluación mediante inhibición de la hemaglutinación y ELISA / Seroprevalence of the swine Influenza virus in fattening pigs in Argentina in the 2002 season: evaluation by hemagglutination-inhibition and ELISA tests

Se evaluó la prevalencia serológica del virus de influenza mediante las pruebas de inhibición de la hemaglutinación (IHA) y ELISA para los subtipos H1N1 y H3N2 en 13 granjas porcinas de Argentina. Se compararon los resultados obtenidos mediante ambas pruebas en términos individuales y de establecimientos. La prevalencia individual por la técnica de IHA fue de 38,46% a 100% para H1 y de 7,69% a 100% para H3. Por la técnica de ELISA, la prevalencia individual fue de 2,33% a 6,9% para H1 y de 9,65% a 48% para H3. No se observaron diferencias significativas entre ambas técnicas a escala de granja (H1: p=0,20; H3: p=0,11). La concordancia entre las pruebas fue nula al tomar como unidad de referencia el animal (H1: 0,005; H3: 0,070), mientras que en términos de establecimiento fue escasa (H1: 0,350; H3: 0,235). Considerando la alta prevalencia individual obtenida por la prueba de IHA y la alta sensibilidad de esta técnica, se podría sugerir que en las poblaciones porcinas de la Argentina circularon cepas virales humanas o cepas porcinas con gran proximidad filogenética a las utilizadas en este estudio desde el año 2002.

The seroprevalence of the Influenza virus against H1N1 and H3N2 was determined by the hemagglutination-inhibition test (HI) and a commercial swine influenza ELISA kit, in 13 Argentinean swine herds. The results of within-herd and between-herd prevalence obtained by both tests were statistically correlated. The within-herd prevalence observed by the HI test varied from 38.46 to 100% against H1 and 7.69 to 100% for H3. When the within-herd prevalence was measured with the ELISA test, it varied from 2.33 to 6.9% for H1 and 9.65 to 48% for H3. No statistical differences were observed at herd level between HI and ELISA (H1: p = 0. 20; H3: p=0.11). No agreement between HI and ELISA detected prevalence was observed when the within-herd prevalence was compared (H1: 0.005; H3: 0.070), while the agreement at herd level was considered poor (H1: 0,350; H3: 0,235). The high within-herd prevalence values observed with the HI test and the high sensibility of this test might show that human strains or swine strains phylogenetically closely related to the humans strains used in the HI test in this study have been affecting the swine population since 2002.

Gripe aviar h5n1: h1n1: ¿la nueva pandemia del siglo? / Avian influenza h5n1: h1n1: the new pandemy of the century?

Las pandemias de gripe se han caracterizado hasta ahora por la adaptación en humanos de un virus que contiene determinantes antigénicos derivados de cepas de virus propios de aves para los cuales no existe inmunidad en humanos. La ausencia de vacunas y de fármacos eficaces contra una posible epidemia provoca una gran expectativa en cuanto a la repercusión que una pandemia de tales magnitudes tendrá sobre la humanidad no sólo en el aspecto económico sino sobre la tasa de mortalidad tan elevada que podría producirse. Este artículo va dirigido al personal de salud, tanto profesionales como estudiantes, con el fin de informarlos y prevenirlos frente a una nueva pandemia de influenza.

The influenza pandemies are characterized by the adaptation in humans of viruses that only affect the avian population. This is because there is not immunity by humans in front of these new serotypes of influenza. The absence of vaccines and efficient drugs against a possible pandemy, provoke huge expectations according to the repercussion of this kind of pandemy in the humanity, not only in the economical aspect but in a possible mortality rate that could be produced. This article is aimed at the professional and students of the health area. Its objective is to inform and prevent them in the case they need to face a new pandemy of influenza.

Identificación de otros agentes infecciosos en casos sospechosos de síndrome cardiopulmonar por hantavirus / Identification of infectious agents in cases suspicious of Hantavirus infection but with negative serology

Background: The diagnosis of acute respiratory illness caused by Hantavirus is based in the rapid and progressive clinical course, epidemiological background and the serological confirmation of the virus. When the presence of the virus is not confirmed a differential diagnosis must be made with other infections. Between 1999 and 2001, the Chilean Public Health Institute received 1063 blood samples from patients with a suspicious clinical picture, to study the presence of Andes strain of Hantavirus. In 134 of these samples, the presence of the virus was confirmed. Aim: To study the presence of other infections in sera from patients with suspected Hantavirus acute respiratory illness but serologically negative for Hantavirus. Material and methods: A retrospective study of 98 serum samples, received at the National Public Health Institute, of patients with negative serology for Hantavirus. The presence of antibodies against influenza virus, Mycoplasma pneumoniae, Leptospira and Streptococcus pneumoniae was determined using Latex techniques. Results: Leptospira was detected in 23 patients, influenza virus in 13, Streptococcus pneumoniae in six and Mycoplasma pneumoniae in one case. Leptospira infections were confirmed in four cases by ELISA determination of IgM antibodies. Influenza virus infection was confirmed in three cases by Hemmaglutation Inhibition Assay. Conclusions: In suspected cases of Hantavirus acute respiratory infection, but with negative serology, other infectious agents such as Leptospira, influenza virus and Streptococcus pneumoniae, must be sought.