Efficacy of some avian influenza H5 vaccines against local highly pathogenic avian influenza viruses subtype H5N8 isolated in 2018 and 2020 in Egypt

Commercial inactivated avian influenza H5 vaccine is used as an essential control strategy for avian influenza disease in Egypt. Since the initial outbreaks of highly pathogenic avian influenza H5N8, the virus has diverged with new genotypes and variant viruses continuing to emerge which mainly stand behind vaccination failure. In the present work, four different commercial avian influenza vaccines were inoculated in specific pathogenic free chickens for assessing its efficacy against local highly pathogenic avian influenza H5N8 virus isolated in 2018 and 2020. Two hundred and forty specific pathogenic free chickens were clustered into four groups; each group was inoculated with the corresponding vaccine (60 specific pathogenic free chickens/vaccine). Sixty specific pathogenic free chicks were kept as control unvaccinated group. Sera collected from vaccinated chicken groups at 3rd and 4th week post vaccination were examined for calculating neutralizing antibodies using heterologous highly pathogenic avian influenza H5N8 2018 and 2020. At 4th week post vaccination, vaccinated chickens were challenged; moreover, oropharyngeal swabs were collected from challenged vaccinated chickens to calculate the viral shedding. Our findings revealed the groups vaccinated with vaccine code no 1 and 2 that contains two vaccine strains (H5N1 and H5N8) of local origin exhibited the highest hemagglutination inhibition titer, protection (percent) and reduction in viral shedding titer when examined by highly pathogenic avian influenza H5N8 2018 while, vaccine code no 3 induced lower antibody response, protection (percent) and reduction in viral shedding, but still within satisfactory level when compared to previous groups. When highly pathogenic avian influenza H5N8 2020 was used, it was found the seroconversion rate, protection (percent) and mean titer of reduction of viral shedding decreased in comparison to those recorded for highly pathogenic avian influenza H5N8 2018. Vaccine code no 4 was impotent to either highly pathogenic avian influenza 2018 or 2020. Accordingly, it was recommended to update vaccine strain according to epidemiological condition and used the predominant circulating strain isolate in challenge test(AU)

La vacuna comercial inactivada H5 se utiliza como estrategia esencial de control de la enfermedad de la gripe aviar en Egipto. Desde los brotes iniciales de la gripe aviar altamente patógena H5N8, el virus ha variado al aparecer continuamente nuevos genotipos y variantes virales, que son los principales responsables del fracaso de la vacunación. En el presente trabajo, cuatro vacunas comerciales diferentes contra la gripe aviar se inocularon en pollos libres de patógenos específicos para evaluar su eficacia contra cepas del virus local de la gripe aviar altamente patógeno H5N8 aisladas en 2018 y 2020. Se agruparon 240 pollos pollos libres de patógenos específicos en cuatro grupos, cada uno fue inoculado con la vacuna correspondiente (60 pollos pollos libres de patógenos específicos/vacuna). Sesenta pollos SPF se mantuvieron como grupo control sin vacunar. Los sueros de los pollos vacunados recogidos en la 3ª y 4ª semana después de la vacunación se examinaron para calcular los anticuerpos neutralizantes contra la gripe aviar heteróloga H5N8 2018 y 2020. En la cuarta semana después de la vacunación, los pollos vacunados fueron retados; además, se recogieron hisopados orofaríngeos de los pollos vacunados retados para calcular la diseminación viral. Nuestros resultados revelaron que los grupos vacunados con las vacunas con códigos nº 1 y 2, que contienen dos cepas vacunales (H5N1 y H5N8) de origen local, mostraron el mayor título de inhibición de la hemaglutinación, protección (por ciento) y reducción del título de excreción viral cuando se evaluaron contra la gripe aviar altamente patógena H5N8 2018, mientras que la vacuna con código nº 3 indujo menor respuesta de anticuerpos, protección (por ciento) y reducción de la excreción viral, pero todavía dentro de un nivel satisfactorio en comparación con los grupos anteriores. Al utilizar la vacuna contra la gripe aviar altamente patógena H5N8 2020, se observó que la tasa de seronconversión, la protección (por ciento) y el título medio de reducción de la excreción viral disminuyeron en comparación con los registrados para la gripe aviar altamente patógena H5N8 2018. La vacuna con código nº 4 no fue potente para la gripe aviar altamente patógena de 2018 o de 2020. Por consiguiente, se recomendó actualizar la cepa de la vacuna de acuerdo con las condiciones epidemiológicas y utilizar el aislamiento de la cepa circulante predominante en la prueba de reto(AU)

Evaluation of Immune Responses and Histopathological Effects against Gamma Irradiated Avian Influenza (Sub type H9N2) Vaccine on Broiler Chicken

Abstract Vaccination is a good strategy for the prevention of avian influenza virus. In this research Gamma Irradiated Avian Influenza (Sub type H9N2) Vaccine (GAIV) was prepared by 30 kGy irradiation and used for vaccination of broiler chickens. The purpose was a comparison of immune responses in the two routes of administration for the GAIV vaccine; intranasal and subcutaneously, use of Montanide ISA70 and Trehalose accompanied with irradiated vaccine and compare with formalin vaccine. The Influenza Virus A/Chicken/IRN/Ghazvin/2001/H9N2 was irradiated and used for vaccine formulation, and formalin inactivated AIV was used as conventional vaccine. Chickens were vaccinated by GAIV with and without Trehalose, GAIV and formalin vaccines with ISA70, two routes of administration were intranasal and subcutaneously. All the vaccinated chickens showed a significant increase in antibody titration. The most significant increase of antibody titration was in irradiated vaccine plus Trehalose groups intranasal and subcutaneously. After the first and second intranasal vaccination, the amount of IFN-gamma increased in the irradiated vaccine plus Trehalose group compared to other groups. However, most of the vaccinated groups did not show any significant increase of IFN-α concentration. Histopathological examination revealed lymphocyte infiltration (++), foci dispersed of hemorrhage and edema in intranasal vaccination groups and in addition to these, thickening of alveolar septa was observed in the injection groups. GAIV vaccine can be a good candidate for vaccine preparation, and Trehalose as a stabilizer protects viral antigenic proteins, also makes more absorbance of antigen by the inhalation route. In vaccinated chickens the ulcers in injected vaccines were lower than intranasal vaccines.

Avaliação situacional de influenza pós pandemia de 2009 - uma breve revisão / Situational assessment of influenza post 2009 Pandemic - a brief review

Os vírus influenza são responsáveis por epidemias anuais com gravidade da doença variável. Causam infecção respiratória aguda com elevada transmissibilidade devido sua alta variabilidade genética, capacidade de adaptação e rápida disseminação. Os vírus influenza apresentam genoma fragmentado,o que ocasiona variações antigênicas frequentes, e consequentemente pode induzir o aparecimento de subtipos mais virulentos, como ocorreu em 2009,quando foi registrada pandemia por um novo vírus Influenza A H1N1. A Organização Mundial de Saúde(OMS) estima que a gripe acometa 5 a 15% da população,ocasionando 3 a 5 milhões de casos graves e 250.000 a 500.000 mortes anualmente. As epidemias anuais de gripe e o risco de novas pandemias tornamo monitoramento epidemiológico do vírus influenza fundamental e, para isto, a OMS coordena a Rede Mundial de Vigilância da Influenza com a finalidade de fornecer informações necessárias para a escolha das variantes virais que farão parte da composição anual da vacina, visto que a vacinação é uma das medidas mais efetivas para prevenção da gripe e suas complicações. Além disso, a rede constitui uma vigilância rápida para identificações de vírus influenza emergentes com potencial epidêmico ou pandêmico.Esta vigilância é viabilizada pelos resultados dos testes laboratoriais que são ferramentas importantes para a Saúde Pública, sendo fundamentais para a contenção e prevenção dos vírus circulantes. O objetivo deste estudo foi apresentar informações relacionadas ao vírus influenza e a doença, como são realizados o diagnóstico e monitoramento pelas redes de vigilâncias mundiais pós-pandemia e, ainda, quais os novos desafios que se apresentam.

Influenza viruses are responsible for annual epidemics with patients presenting variable degrees of diseases everity. These virus can cause acute respiratory infection with a high transmissibility due to its high genetic variability, adaptability and rapid spread. Influenza viruses have fragmented genome which causes frequent antigenic variation, which can result in more virulent subtypes emergence, as occurred in 2009 when it was described a new pandemic influenza virus H1N1. WHO estimates that flu affects 5-15% of the population and it causes 3 to 5 million of severe cases and 250.000 to 500.000 deaths annually. The annual influenza epidemics and the new pandemics risk high lights the importance of Influenza virus epidemiological monitoring. Based in this concern WHO created and coordinates the Global Influenza Surveillance and Response System in order to provide necessary information for viral variants selection that will be part of vaccine annual composition, since that, vaccination is one of the most effective measures for influenza prevention and its complications. In addition, the network is a rapid surveillance of emerging influenza virus identifications with potential to cause epidemic or pandemic situations. The surveillance isenable due to laboratory tests results which are important tools for public health, with essential role for circulating viruses containment and prevention. The aim of this study was to present information related to influenza virus and flu disease, how the diagnosis and monitoring are performed by global surveillance networks at post pandemic time and, also,the new challenges facing.

comparison of the effects of commercial prebiotic [safmannan, biomos and fermacto] on performance, egg quality and antibody titer of Avian Influenza and Newcastle disease in laying hens

Effects of different sources of prebiotic on performance and immune response in laying hens were evaluated in this study. The aim of this experiment was to compare the effects of commercial prebiotics on performance, egg quality and antibody titer against Newcastle disease [ND] and Avian Influenza [AI] in laying hens. The experiment was performed for 11 weeks [from 33 to 44 weeks of age] on 240 laying hens [the LSL strain], in a completely randomized design with 4 treatments, and 5 replicate for each treatment and 12 birds for each replicate. Treatments were: 1] control; 2] control +Safmannan; 3] control +Bio-Mos and 4] control +Fermacto. The results showed that feed intake, feed conversion ratio and egg production percentage were not affected by different sources of prebiotic. However, egg weight and egg mass were significantly increased [p<0.05] by adding prebiotic, in comparison with control diet. Egg specific gravity and shell thickness were increased [p<0.05] by prebiotic addition. The results of experiment showed that antibody titers against AI and ND were significantly increased [p<0.05] by prebiotics compared with control group. The results showed that the effects of different sources of prebiotic on performance and immune response of laying hen are similar. However, inclusion of prebiotic in the diet results in improvement of the performance and antibody titer against Influenza and Newcastle

Estratificación epidemiológica del riesgo de las enfermedades emergentes y reemergentes por áreas de salud. Provincia de Matanzas, 2002-2006 / Risk epidemiologic stratification of the emergent and re-emergent diseases per health areas. Province of Matanzas, 2002-2006

Las enfermedades emergentes y reemergentes constituyen un problema de salud que preocupa a los gobiernos y a las autoridades de salud pública, por los efectos económicos y sociales que pueden ocasionar. Se realizó un estudio observacional descriptivo en la población de la provincia de Matanzas, distribuida geográficamente en sus áreas de salud, con el propósito de estratificar el riesgo para las enfermedades emergentes y reemergentes, en el período 2002-2006. Un grupo de expertos seleccionaron las enfermedades a estudiar y los indicadores, quedando definidos así: para la tuberculosis y el VIH/sida, la tasa de prevalencia y de letalidad; para el dengue y el paludismo, los casos importados y el índice de infestación; para la influenza aviar y la fiebre del Oeste del Nilo Occidental (FNO), el asentamiento de aves migratorias, el arribo de viajeros de áreas endémicas, y también para esta última, el índice de infestación. Los datos fueron obtenidos de las tarjetas de Enfermedades de Declaración Obligatoria y certificados de defunción, de la Dirección Provincial de Salud, del Centro Provincial de Higiene y Epidemiología, del sistema de vigilancia vectorial de la Unidad Provincial de Vectores y de aves migratorias de la Dirección Provincial de Medicina Veterinaria y el Ministerio de Ciencia Tecnología y Medio Ambiente (CITMA). Se obtuvo como resultado que Playa, Varadero, Agramante y Jagüey Grande fueron las áreas de salud de mayor riesgo, lo que es de vital importancia para los cuadros a diferentes niveles del sistema, ya que posibilita con una base científica la reorientación de la vigilancia, la organizar los servicios de salud e intervención oportuna.

The emergent and re-emergent diseases are a health problem worrying governments and public health authorities because of the economic and social effects they can produce. We carried out a descriptive observational study in the population of the province of Matanzas, geographically distributed in their health area, with the purpose of stratifying the risk for the emergent and re-emergent diseases, in the period 2002-2006. A group of experts selected the diseases to study and the indicators, being defined this way: for the tuberculosis and HIV/AIDS, the prevalence rate and the lethality; for dengue and malaria, the imported cases and the infestation index; for the avian flu and the West Nile fever, the migratory birds settlement and the traveler arrival from the endemic areas, and for the last one also the infestation rate. The data were collected from the cards of Obligatory Declaration Diseases and the decease certifications, from the Provincial Direction of Health, the Provincial Center of Hygiene and Epidemiology, the vectorial surveillance system of the Provincial Unit of Vectors, the Provincial Center of Veterinary Medicine, and the Ministry of Sciences, Technology and Environment. As a result we obtained that Playa, Varadero, Agramonte and Jagüey Grande were the health areas at higher risk. This is of great importance for the executives at the different levels of the system, making possible the reorientation of the surveillance, the organization of the health services and te opportune intervention on a scientific basis.

Estudo da eficácia de espuma para a depopulação de avespara situações de emergência sanitária / Experimental evaluation of foam-based poultry depopulation for emergencies

São inúmeras as dificuldades observadas na depopulação de elevado número de aves e é importante proceder-se àdepopulação no interior do próprio aviário por questões de biossegurança do homem em casos de emergência sanitáriacausada por doenças de aves de elevada transmissibilidade, como a influenza aviária e a doença de Newcastle. Construiuseo equipamento gerador de espuma para provocar a anóxia física em aves. Verificou-se a eficácia da espuma geradaatravés do uso de líquido detergente de alta expansão sobre o sacrifício de galinhas, avaliando-se os sinais sensoriais,tempo de morte, letalidade e lesões macro e microscópicas. Duzentas galinhas de postura com 78 semanas de idadeforam divididas em dez grupos experimentais e submetidas a diferentes períodos de exposição à espuma, variando de5min30s a 8min15s . A partir de seis minutos de exposição à espuma 100% das aves foram mortas. A presença de bolhasde espuma na cavidade oral e traqueia foram constatadas em todos os períodos de exposição à espuma, indicando aocorrência de asfixia física. Congestão nas mucosas da cavidade oral e traqueia foram também observadas em todos osperíodos de exposição. No exame histopatológico dos pulmões de todas as aves, observou-se a presença de congestãoe hemorragia difusa de moderada intensidade. Nenhuma alteração foi observada na traqueia das aves. A eficácia daespuma como método de depopulação de aves foi constatada neste trabalho, podendo ser recomendada diante danecessidade de atendimento a emergências sanitárias.

There are several difficulties in the control of quick spreading and highly contagious poultry diseases such as avianinfluenza and Newcastle disease, which require large numbers of poultry to be rapidly killed inside the poultry housesin order to minimize human exposure and disease spreading. We have built and tested an equipment that uses a waterbasedfoam from high expansion fire detergent that induces poultry anoxia measured by sensorial signs, time to death,lethality and macro and microscopically lesions. Two hundred 78-weeks old hens were divided into ten groups andexposed to different times of death according to exposure to water-foam varying from 5min30s to 8min15s. All poultrydied after six minutes of water-foam cover. Foam bubbles were observed in oral cavity and trachea of all poultry ateach time of exposure to foam, revealing physical asphyxia. Macroscopically, congestion in oral cavity and in tracheamucosa was observed. Histopathology revealed diffuse and moderate hemorrhage in lungs and no lesion in trachea.The efficacy of water-foam procedure for poultry depopulation was demonstrated validating its recommendation incase of emergency.

Influenza A: [revisión] / Influenza A: [review]

La influenza es una enfermedad viral aguda que afecta una gran parte de la población mundial cada año. Es producida por los virus de la influenza, los cuales pertenecen a la familia Orthomyxoviridae. Se conocen tres tipos: A, B y C; los virus tipo A afectan una gran variedad de especies animales, incluyendo la humana, en tanto que los tipos B y C usualmente se limitan al hombre, aunque se han aislado de focas y cerdos, respectivamente...

Risk factors, threats and prevention of highly pathogenic avian influenza (HPAI) in African countries

Highly pathogenic avian influenza (HPAI) is a viral disease that affects the digestive; nervous and respiratory systems of all domestic and wild birds with high morbidity and mortality. It is highly contagious disease which can be fatal in humans. The avian influenza viruses (AIVs) are classified as types A; B and C with 15 subtypes of the type A. To date; all disease causing HPAI Viruses belong to H5 or H7 subtypes; and affect pigs and humans with the pigs serving as a mixing vehicle for re-assortment of the virus. The domestic ducks get infected without showing clinical signs and serve as a source of infection for domestic poultry. Outbreaks of HPAl in Europe; Asia and Turkey are reported to be associated; with the presence of wet lands and lakes where migratory birds rest. In some African countries like Nigeria; such wet lands exist with free flying wild birds and domestic ducks visiting and resting. The possible source of introduction into a country could be through importation or smuggling of infected poultry products across the borders and through migratory birds that fly through identified pathways. The status of HPAl in many African countries including Nigeria is still under investigation so that appropriate strategies / measures to prevent introduction of the disease into the country can be implemented and / or strengthened through restriction of importation of poultry and poultry products from high risk countries; effective disease surveillance; functional National Veterinary services; quarantine and community based participatory epidemiological system for HPAI surveillance and control. This article reviewed the global epidemiology and risk factors of HPAI infection in Nigeria and other African countries with emphasis on specific preventive measures that can reduce introduction of the virus into the country and the epidemiological surveillance for case detection / identification; screening and management. This review provides useful information and updates for health workers in tropical countries on the trends of AIVs and HPAI; diagnostic criteria using case definitions for both community and health facility levels and management protocols for confirmed cases as recommended by the World health Organization

Avian influenza protection knowledge, awareness, and behaviors in a high-risk population in Suphan Buri Province, Thailand.

Avian influenza (Al) had outbreaks in Thailand from January 2004 to December 2005, which resulted in 22 human cases, and 14 deaths. Three confirmed cases were reported in Suphan Buri Province in 2004, one of whom died. A cross-sectional study aimed to investigate knowledge, attitudes, and practices about AI in Song Phi Nong District of Suphan Buri Province. Most of the respondents had moderate levels of knowledge. Most of their attitudes towards and practices of the prevention and control of AI were also appropriate. However, the peoples' knowledge about major signs and symptoms of AI was limited. The study suggested that those who had received information from media had better attitudes towards and practices of AI prevention and control, compared with those who had not received information from media. Therefore, the media played an important role in improving knowledge, attitudes, and behaviors; but for the better protection from AI, continuing health education will be necessary in Thailand.

Avian Influenza: Should China Be Alarmed?

Avian influenza has emerged as one of the primary public health concern of the 21st century. Influenza strain H5N1 is capable of incidentally infecting humans and other mammals. Since their reemergence in 2003, highly pathogenic avian influenza A (H5N1) viruses have been transmitted from poultry to humans (by direct or indirect contact with infected birds) in several provinces of Mainland China, which has resulted in 22 cases of human infection and has created repercussions for the Chinese economy. People have been concerned whether a new pandemic will occur in the future. The eradication of pathogenic avian influenza viruses appears to be the most effective way to prevent an influenza pandemic. This paper will examine the features of H5N1, including incidence, infection, immunity, clinical management, prevention and control, and therapy in Mainland China.

La influenza, un problema vigente de salud pública / Influenza, an existing public health problem

La influenza estacional es una enfermedad respiratoria aguda, recurrente y común que se conoce desde la antigüedad y se presenta sobre todo durante los meses de invierno con un elevado impacto para la salud pública mundial. La enfermedad se manifiesta con altas tasas de morbilidad en individuos de todas las edades y elevadas tasas de mortalidad en niños, individuos mayores de 60 años, pacientes con enfermedades crónicas y mujeres en gestación. Las estrategias de prevención incluyen el uso de vacunas: inactivadas, subunitarias o vacuna con virus genéticamente modificados. Dos subtipos de virus de influenza tipo A y un virus de influenza tipo B causan la enfermedad en humanos. Los virus de influenza A que afectan a los humanos mutan con facilidad, por lo que con frecuencia aparecen nuevas variantes antigénicas de cada subtipo, lo que obliga a incluir dichas variantes en las vacunas anuales para brindar una adecuada protección a la población. La influenza pandémica se refiere a la introducción y posterior diseminación mundial de un nuevo virus de influenza en la población humana, lo que ocurre de manera esporádica, y que debido a que los humanos carecen de inmunidad para el nuevo virus pueden suscitarse epidemias graves con elevadas tasas de morbilidad y mortalidad. Históricamente el origen de las pandemias de influenza se debe a la transmisión de virus de aves al hombre o la transferencia de genes de éstos a los virus de la influenza estacional. En las aves acuáticas silvestres, tanto migratorias como costeras, se mantiene una gran diversidad de subtipos de virus de influenza, los cuales se introducen eventualmente en aves domésticas, donde algunos virus adquieren la capacidad de infectar a mamíferos, incluido el hombre. El proceso de adaptación de los virus aviarios a hospederos mamíferos requiere tiempo, por lo que la presentación de estos casos puede tardar varios años. Desde diciembre de 2003, en varios países del sureste asiático, las aves domésticas han sido afectadas por una epidemia de influenza aviaria (subtipo H5N1) de grandes proporciones. A febrero de 2006 la epidemia ya afectó a países de Europa y Africa, con un fuerte impacto económico para la avicultura comercial por el sacrificio de más de 180 millones de aves. Algunos linajes de este virus adquirieron la capacidad de cruzar la barrera de especie e infectaron de manera directa pero incipiente a la población humana...

Influenza aviar / Avian influenza

Se hace referencia a las características virológicas de la influenza aviar, expansión geográfica y migración de las aves en los Continentes, probabilidad de riesgo de pandemia en un futuro cercano, descripción clínica de la patología y terapéutica disponible, así como también a los avances preventivos y recomendaciones.