Dossier investigation: identification of the agent

Influenza in birds is caused by infection with viruses of the family Orthomyxoviridae placed in the genus influenzavirus A. Influenza A viruses are the only orthomyxoviruses known to naturally affect birds. Many species of birds have been shown to be susceptible to infection with influenza A viruses; aquatic birds form a major reservoir of these viruses, and the overwhelming majority of isolates have been of low pathogenicity (low virulence) for chickens and turkeys. Influenza A viruses have antigenically related nucleocapsid and matrix proteins, but are classified into subtypes on the basis of their haemagglutinin (H) and neuraminidase (N) antigens (World Health Organization Expert Committee, 1980). At present, 16 H subtypes (H1–H16) and 9 N subtypes (N1–N9) are recognised with proposed new subtypes (H17, H18) for influenza A viruses from bats in Guatemala (Swayne et al., 2013; Tong et al., 2012; 2013). To date, naturally occurring highly pathogenic influenza A viruses that produce acute clinical disease in chickens, turkeys and other birds of economic importance have been associated only with the H5 and H7 subtypes. Most viruses of the H5 and H7 subtype isolated from birds have been of low pathogenicity for poultry. As there is the risk of a H5 or H7 virus of low pathogenicity (H5/H7 low pathogenicity avian influenza [LPAI]) becoming highly pathogenic by mutation, all H5/H7 LPAI viruses from poultry are notifiable to OIE. In addition, all high pathogenicity viruses from poultry and other birds, including wild birds, are notifiable to the OIE.

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Basic information about avian influenza

Avian influenza is usually an inapparent or nonclinical viral infection of wild birds that is caused by a group of viruses known as type A influenzas. These viruses are maintained in wild birds by fecal-oral routes of transmission. This virus changes rapidly in nature by mixing of its genetic components to form slightly different virus subtypes. Avian influenza is caused by this collection of slightly different viruses rather than by a single virus type. The virus subtypes are identified and classified on the basis of two broad types of antigens, hemagglutinan (H) and neuraminidase (N); 15 H and 9 N antigens have been identified among all of the known type A influenzas.

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Dossier Avian Influenza: the next pandemic?

Kathleen Harriman PhD, MPH, RN published an interesting presenation on the relationship between outbreaks of high pathogen Avian Influenza and the risks of the next human pandemics. Kathy has worked in the healthcare and public health fields for the past 35 years as a pediatric emergency room nurse, a hospital infection control practitioner, and as an infectious disease epidemiologist.

For the last two years, Kathy has been Chief of the Vaccine Preventable Disease Epidemiology Section in the Immunization Branch of the California Department of Public Health. Prior to joining CDPH, she worked for 15 years at the Minnesota Department of Health in a number of public health areas, including HIV/AIDS and the Emerging Infections Program.

During her last five years there she supervised the Infection Control Unit where she worked on community-associated MRSA and a variety of infectious disease issues, including many community and healthcare-associated outbreaks. Kathy has an MPH from the University of Sydney (Australia) and a PhD from the University of Minnesota.

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dossier eendagskuikens: Hoeveel tijd heeft de pluimvee sector?

In Nederland worden jaarlijks 45 miljoen eendagshaantjes van legrassen gedood. Tijdens het symposium ‘Alternatieven voor het doden van eendagshaantjes’ zijn mogelijke alternatieven getoond en bediscussieerd.

Het symposium werd georganiseerd door Wageningen UR, en vond plaats op 8 september, met 40 deelnemers uit de pluimveesector (fokkerij, broederij, brancheorganisatie), het ministerie van Economische Zaken, de NVWA en het onderzoek.

Vooralsnog bestaat er weinig maatschappelijke ophef over de massale doding van de haantjes, maar daar zou de komende jaren verandering in kunnen komen.

De discussie over dit onderwerp heeft inmiddels in Duitsland geleid tot het verbod op het levend vermalen van eendagskuikens en bedrijven als Nestle en Unilever hebben in hun CSR strategie opgenomen dat zij voor het volledig uitbannen van het doden van eendagshaantjes zijn.

Het is dus nog maar de vraag of de markt bereid is de sector de tijd te gunnen om met een praktijkrijp alternatief te komen. Daarom doen de  sector en de overheid er goed aan na te gaan hoe ze de ontwikkeling van een alternatief kunnen versnellen, want zoals het er nu naar uit ziet kan het nog wel vijf tot tien jaar duren voordat een praktijkrijp alternatief beschikbaar is.

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