Impact of H5N8 duck and chicken viral isolates on the immunological profile of vaccinated specific pathogen free chickens

Nowadays, there is a global concern about outbreaks caused by the highly pathogenic avian influenza virus H5N8 clade 2.3.4.4 which caused devastating losses in the poultry industry sector. This clade was subdivided into two waves: clade 2.3.4.4A from 2014 to 2015 and clade 2.3.4.4b from 2016 until now. In this literature we aimed to evaluate the efficacy of recently used inactivated commercial avian influenza vaccines against two new Egyptian highly pathogenic avian influenza virus H5N8 isolates of clade 2.3.4.4b, A/chicken/Egypt/1526v/2020/H5N8 (H5N8-CH) and A/Duck/Egypt/Qalubia321/2021 (H5N8-D). Three-week-old specific pathogen free chickens were vaccinated with eight types of the most recently used inactivated avian influenza vaccines containing homologous and heterologous virus to the circulating H5N8 isolates. All specific pathogen free chicken groups were bled weekly post vaccination for antibody analysis using two H5N8 isolates of chicken and duck origin as antigen in hemagglutination inhibition test. Also, all vaccinated chicken groups were challenged 4 weeks post vaccination against the H5N8 duck isolate with a dose of 109 EID50/0.1 mL per chicken to measure the protection percentage of the commercial vaccines used. The results showed that vaccines with homologous and heterologous virus showed variable degrees of accepted protection percentage ranged from 90percent to 100percent, thus it was concluded that not only the genetic and antigenic match of the vaccine strains with the circulating highly pathogenic avian influenza viruses influences vaccine efficiency; other factors, such as manufacturing procedures, adjuvant, antigen content, vaccine dose and administration factors could affect vaccine efficacy, therefore, further vaccine development studies are needed to improve the percentage of protection and prevention of viral shedding against local highly pathogenic avian influenza H5 viruses in Egypt(AU)

En la actualidad, existe una preocupación mundial por los brotes causados por el virus de la gripe aviar altamente patógena H5N8 clado 2.3.4.4 que causó pérdidas devastadoras en el sector de la industria avícola. Este clado se subdividió en dos oleadas: clado 2.3.4.4A de 2014 a 2015 y clado 2.3.4.4b de 2016 hasta ahora. En el presente trabajo, dos aislamientos egipcios de la gripe aviar altamente patógena H5N8 del clado 2.3.4.4b, A/chicken/Egypt/1526v/2020/H5N8 (H5N8_CH) y A/Duck/Egypt/Qalubia321/2021 (H5N8_D), se utilizaron para evaluar la eficacia de vacunas comerciales inactivadas contra la gripe aviar de reciente utilización. Pollos libres de patógenos específicos de tres semanas de edad fueron vacunados con ocho vacunas inactivadas contra la influenza aviar, de uso reciente, que contenían virus homólogos y heterólogos a los aislamientos circulantes de H5N8. Todos los grupos de pollos libres de patógenos específicos fueron sangrados semanalmente tras la vacunación para el análisis de anticuerpos; dos virus H5N8 aislados de pollo y pato se utilizaron como antígeno en la prueba de inhibición de la hemaglutinación. Además, todos los grupos de pollos vacunados fueron retados 4 semanas después de la vacunación con el virus H5N8 aislado de pato, con una dosis de 109 EID50/0,1 mL por pollo, para medir el porcentaje de protección de las vacunas comerciales utilizadas. Los resultados mostraron que las vacunas con virus homólogos y heterólogos presentaron grados variables de aceptada protección, la que osciló entre el 90 por ciento y el 100 por ciento, por lo que se concluyó que no sólo la coincidencia genética y antigénica de las cepas vacunales con los virus circulantes de la influenza aviar altamente patógena influye en la eficacia de la vacuna; otros factores, como los procedimientos de fabricación, el adyuvante, el contenido en antígenos, la dosis de la vacuna y los factores de administración podrían afectar a la eficacia de la vacuna, por lo que es necesario seguir estudiando el desarrollo de vacunas para mejorar la protección y la prevención de la excreción viral contra los virus H5 de la influenza aviar altamente patógena locales en Egipto(AU)

Enhancing Pandemic Influenza Preparedness: 2017 and beyond

A Regional working group meeting was held on 21-22 May 2017 to monitor the progress of activities for improving Pandemic Influenza Preparedness in the Eastern Mediterranean Region of WHO

Evaluación in silico de una epidemia de influenza aviar AH5N1 con transmisión humano-humano: efecto de las medidas sanitarias en Valencia, Venezuela, 2012 / In silico evaluation of an aviar influenza AH5N1 virus outbreak with human to human transmission: effects of sanitary measures in Valencia, Venezuela, 2012

Introducción: Existe el riesgo de una pandemia de influenza aviar por virus AH5N1. Objetivo: Conocer la magnitud e impacto en áreas latinoamericanas de una pandemia AH5N1 a fin de planificar las medidas sanitarias para reducir la morbimortalidad. Material y Método: Mediante el simulador InfluSim se modeló una epidemia por virus AH5N1 con transmisión Humano-Humano, en Valencia, Venezuela. Se calculó el día de máximo número de casos, cantidad de enfermos moderados, graves, expuestos, muertos, y costos en cinco escenarios diferentes: sin intervención sanitaria; tratamiento antiviral; reducción en 20% del contacto en la población; cierre de 20% de las instituciones educativas; reducción de 50% de las reuniones públicas. Parámetros usados: Población: 829.856 habitantes, Porcentaje de riesgo 6-47%, Contagiosidad índice (Ro) 2,5; Contagiosidad relativa 90%, Tasa de letalidad global 64,1 %, costos según Canasta Básica oficial. Resultados: En 200 días de epidemia: Muertes totales por escenario: a: 29.907; b: 29.900; c: 9.701; d: 29.295 y d: 14.752. Similar tendencia en costos. Discusión: Reducir 20% los contactos de la población produjo una reducción significativa de 68% en el número de casos. La epidemia colapsará los sistemas de salud disponibles por cantidad de casos. El tratamiento antiviral no es eficiente durante la epidemia. La reducción en los contactos interpersonales muestra ser la mejor medida sanitaria.

Background: There is a risk for an avian influenza AH5N1 virus pandemia. Aim : To estimate the magnitude and impact of an AH5N1 pandemic in areas of Latin-America in order to design interventions and to reduce morbidity-mortality. Methods : The InfluSim program was used to simulate a highly pathogenic AH5N1 aviar virus epidemic outbreak with human to human transmission in Valencia, Venezuela. We estimated the day of maximal number of cases, number of moderately and severely ill patients, exposed individuals, deaths and associated costs for 5 different interventions: absence of any intervention; implementation of antiviral treatment; reduction of 20% in population general contacts; closure of 20% of educational institutions; and reduction of 50% in massive public gatherings. Simulation parameters used were: population: 829.856 persons, infection risk 6-47%, contagiousness Index Rh o 2,5; relative contagiousness 90%, overall lethality 64,1% and, costs according to the official basic budget. Results: For an outbreak lasting 200 days direct and indirect deaths by intervention strategies would be: 29,907; 29,900; 9,701; 29,295 and 14,752. Costs would follow a similar trend. Discussion: Reduction of 20% in general population contacts results in a significant reduction of up to 68% of cases. The outbreak would collapse the health care system. Antiviral treatment would not be efficient during the outbreak. Interpersonal contact reduction proved to be the best sanitary measure to control an AH5N1 theoretical epidemic outbreak.

Brote de influenza A (H1N1) humano en pavos en un criadero comercial, Valparaíso, Chile: 2009 / Outbreak of human A (H1N1) influenza in turkeys of a commercial poultry farm, Valparaiso, Chile: August 2009

The Chilean Ministry of Health (MINSAL) led an investigation to identify associated factors to human influenza A (H1N1) infection in turkeys from poultry farms, Valparaíso. The Agriculture and Livestock Farming Service (SAG) informed the detection of influenza A (low pathogenicity) in turkeys and the Public Health Institute (ISP) confirmed influenza A (H1N1).The study included 100% of operative wards: 31% presented positive event (influenza A (H1N1)); 60% if considered only reproductive wards. Dissemination and dispersion velocity of 13 wards in 18 days evidenced a continuous common source. Interviews were performed to 89% of workers of whom 20% presented influenza-like disease: 26% from reproductive wards and 4% from raising and rearing farms. Of15 risk factors studied insemination and age in females showed statistically significant RR in low oviposition index wards. A man-bird transmission is proposed, through direct transmission of saliva during manual insemination or indirect transmission through contaminated semen. To the authors, this is the first turkey 2009 influenza H1N1 outbreak detected worldwide,in this case with a documented cloacal transmission path.

El MINSAL lideró una investigación para identificar factores asociados a infección por influenza A(H1N1) en pavos de planteles avícolas, Valparaíso. El Servicio Agrícola Ganadero informó la detección de influenza A (baja patogenicidad) en pavos y el ISP confirmó influenza A(H1N1). El estudio incluyó 100% de los pabellones operativos: 31% presentó evento positivo (influenza A(H1N1); 60% al considerar sólo pabellones de reproducción. La diseminación y velocidad de dispersión de 13 pabellones en 18 días evidenció una fuente común continua. Se entrevistó a 89% de los trabajadores y 20% presentó ETI: 26% de pabellones de reproducción y 4% de granjas de cría y recría. De 15 factores analizados, inseminación y edad de las hembras mostraron RR estadísticamente significativos en los planteles con baja ovipostura. Se plantea transmisión hombre-ave directa por saliva en inseminación manual o transmisión indirecta por semen contaminado. Es el primer brote de influenza A(H1N1) 2009 en pavos detectado en el mundo y que se comprueba vía de transmisión cloacal.

Swine Origin Influenza (Swine Flu).

Swine origin influenza was first recognized in the border area of Mexico and United States in April 2009 and during a short span of two months became the first pandemic. The currently circulating strain of swine origin influenza virus of the H1N1 strain has undergone triple reassortment and contains genes from the avian, swine and human viruses. It is transmitted by droplets or fomites. Incubation period is 2 to 7 days. Common clinical symptoms are indistinguishable by any viral respiratory illness, and include fever, cough, sore throat and myalgia. A feature seen more frequently with swine origin influenza is GI upset. Less than 10% of patients require hospitalization. Patients at risk of developing severe disease are – younger than five years, elderly, pregnant women, with chronic systemic illnesses, adolescents on aspirin. Of the severe manifestations of swine origin influenza, pneumonia and respiratory failure are the most common. Unusual symptoms reported are conjunctivitis, parotitis, hemophagocytic syndrome. Infants may present with fever and lethargy with no respiratory symptoms. Diagnosis is based on RT PCR, Viral culture or increasing neutralizing antibodies. Principle of treatment consist of isolation, universal precautions, good infection control practices, supportive care and use of antiviral drugs. Antiviral drugs effective against H1N1 virus include: oseltamivir and zamanavir. With good supportive care case fatality is less than 1%. Preventive measures include: social distancing, practicing respiratory etiquette, hand hygiene and use of chemoprohylaxis with antiviral drugs. Vaccine against H1N1 is not available at present, but will be available in near future.

Emerging influenza virus: a global threat.

Since 1918, in?uenza virus has been one of the major causes of morbidity and mortality, especially among young children. Though the commonly circulating strain of the virus is not virulent enough to cause mortality, the ability of the virus genome to mutate at a very high rate may lead to the emergence of a highly virulent strain that may become the cause of the next pandemic. Apart from the influenza virus strain circulating in humans (H1N1 and H3N2), the avian influenza H5N1 H7 and H9 virus strains have also been reported to have caused human infections, H5N1 H7 and H9 have shown their ability to cross the species barrier from birds to humans and further replicate in humans. This review addresses the biological and epidemiological aspects of influenza virus and efforts to have a control on the virus globally.

La primera pandemia del siglo XXI / The first pandemic disease of XXI century

La gripe aviar es una enfermedad causada por el virus de la influenza tipo A, perteneciente a la familia Orthomyxoviridae, unos 200 millones de aves muertas o sacrificadas y el deceso de 129 personas es el saldo actual de la infección por la misma. Teniendo en cuenta la inminente llegada a nuestro continente y en especial a Cuba, decidimos realizar esta revisión bibliográfica, para ello consultamos las bases de datos CUMED, LILACS, MEDLINE, WHOLIS y el localizador de información de salud LIS Cuba; en la misma se expone de forma actualizada sus principales características microbiológicas, epidemiológicas, clínicas y su situación actual el mundo. Se aborda además sobre la existencia del Sistema de Vigilancia cubano para esta enfermedad y su fortalecimiento, así como la repercusión social, económica y en materia de salud pública que produciría la llegada de lo que ya se considera la posible primera pandemia del presente siglo.

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.

Influenza humana y aviaria: pasado, presente y futuro / Avian and human influenza: past, present and future

Se revisa la epidemiología de la influenza en los últimos años y el brote en curso de influenza aviaria y sus riesgos para el hombre. En el siglo pasado hubo tres pandemias graves de influenza humana causadas por distintos subtipos de virus A que se extendieron por todo el mundo. Según las evidencias clínicas, de laboratorio y epidemiológicas disponibles, existe un riesgo real de una nueva pandemia que eventualmente afectaría al hombre derivada de la epidemia aviaria, A/H5N1, cuyo principal reservorio son aves migratorias. Se inició en Hong Kong en el año 2003 propagándose con gran rapidez a la población avícola en varios países de Asia, Rusia, Macedonia, Colombia y Turquía. Chile no ha sido afectado. La trasmisión ave-hombre está documentada en un número reducido de casos pero se teme que el virus, mediante recombinación genética con cepas humanas, adquiera la capacidad de infectar y trasmitirse al hombre dando curso a su diseminación explosiva. Se discute la estrategia, indicaciones y limitaciones de su prevención y tratamiento incluyendo vigilancia epidemiológica, empleo de fármacos antivirales e inmunización.

The effect of temperature and UV light on infectivity of avian influenza virus (H5N1, Thai field strain) in chicken fecal manure.

Normal chicken fecal manure (pH 8.23 and 13.7% moisture) was investigated for infectivity of the avian influenza virus (AIV; H5N1). The manure was divided into three groups; each group was inoculated with AIV at 2.38 x 10(5.25) ELD50. After viral inoculation, the first group was incubated at 25 degrees C. The second group was kept at 40 degrees C, and the last group was exposed to ultraviolet light at 4-5 microw/cm2 at room temperature. After incubation, a 20% suspension of manure was filtered and the filtrates were inoculated into 9-11 day-old embryonated chicken eggs per WHO protocol (2002). The results showed that at 25 degrees C the virus lost its infectivity within 24 hours, and at 40 degrees C within 15 minutes. UV light, however, could not destroy the infectivity of the virus even after exposure for 4 hours.

Awareness of avian influenza ["bird flu"] among attendees of a primary healthcare clinic in Riyadh

Little research has assessed the quality of manufacturer-provided prescribing information or documented differences in key aspects of drug information among different marketed generic products of the same drug, particularly in the Middle East and Arabian Gulf. We assessed the quality of written prescribing information for selected generic drugs marketed in Saudi Arabia and manufactured in various countries of the Middle East. We assessed the correctness and completeness of information pertaining to indications, dosage, cautions/contraindications, side effects and drug interactions in 37 package inserts for generic products registered in Saudi Arabia and manufactured in the Middle East, including atenolol [6 inserts], fluoxetine [4 inserts], ciprofloxacin [11 inserts], metformin [7 inserts] and omeprazole [9 inserts]. We also described deficiencies in the quality and quantity of manufacturer-provided information that could be misleading to patients and prescribers. We found substantial disagreement in information between generic package inserts versus the British National Formulary and the package insert of the brand product marketed in Saudi Arabia. A cumulative average of 63 +/- 16% of drug information indicators were in agreement with these standard references. Section headings with the least conformity with study references were those related to dosage [57 +/- 28%] and side effects [54 +/- 30%].Our results indicate that national authorities should implement appropriate measures aimed at removing misleading and incorrect information in generic package inserts and incorporating crucial prescribing information that is missing. National authorities in the Middle East and Arabian Gulf should strengthen collaboration and information interchange among each other and with international agencies to maintain common quality standards for delivering information through package inserts