What is Avian Influenza (AI)?
Avian influenza (AI) is a disease of birds, caused by Type “A” influenza viruses which can affect several species of domestic poultry, such as chickens, turkeys, quails, guinea fowl, ducks, etc., as well as pet birds and wild birds. Avian influenza viruses have also been isolated, although less frequently, from mammalian species including rats, mice, weasels, ferrets, pigs, cats, tigers, dogs, horses, as well as humans.
What means Low Pathogenic/Highly Pathogenic?
There are many strains of AI viruses that can generally be classified into two categories according to the severity of disease in poultry:
- low pathogenic (LPAI) that typically causes little or no clinical signs in birds;
- highly pathogenic (HPAI) that can cause severe clinical signs and possible high mortality rates in birds.
The differentiation between low and high pathogenicity avian influenza is based on the results of laboratory tests, which are described in the OIE Diagnostic Manual.
This characterisation of avian influenza viruses as low or high pathogenicity (severity of disease) is specific to poultry and other birds, and not necessarily to other species that can be susceptible to avian influenza viruses including humans.
What is influenza A (H5N8)?
This virus was detected early this year in Asia in poultry species in the Republic of Korea, Japan and in China. In January 2014, the authorities of the Republic of Korea reported the first poultry cases of disease due to the infection with a highly pathogenic strain H5N8 of avian influenza viruses (type A). The total of 29 outbreaks was reported in birds involving geese, chickens and ducks. Close to 600,000 birds were culled. This event was resolved in September 2014. In September 2014, the country reported a new outbreak in ducks reared for meat production where 1200 birds died and 19,800 were culled to control the disease.