Transmission of influenza viruses

Avian influenza viruses (AIV) are endemic in wild birds worldwide. According to the major surface antigens hemagglutinin (HA) and neuraminidase (NA), AIV are serologically classified into 16 HA and 9 NA subtypes that exist in different combinations. AIV replicate in the gastrointestinal tract of their hosts and are shed into the environment at large amounts, facilitating transmission to other species. In domestic poultry, highly pathogenic avian influenza viruses (HPAIV) of subtypes H5 and H7 may emerge, which cause fatal disease in poultry ("fowl plague") and also have zoonotic potential. Our work with low-pathogenic avian influenza virus (LPAIV) isolates from wild waterfowl indicates that some viruses can efficiently replicate in chickens without prior adaptation and are efficiently transmitted to sentinel chickens whereas other isolates are not shed from these animals. Taking advantage of reassortant and mutant LPAIV we aim at identifying the molecular determinants which are important for transmission.

Funding:

  • Federal Food Safety and Veterinary Office (grant number 1.10.11): Adaptation processes of wild waterfowl isolates of avian influenza during repeated passages in domestic chickens and ducks.