People can catch some bird diseases , for example psittacosis , salmonellosis , campylobacteriosis , Newcastle 's disease , mycobacteriosis , influenza , giardiasis , and cryptosporiadiosis . In 2005 , there is an epidemic of bird influenza spreading through some parts of the world , often called avian flu . Birds can act as vectors for spreading diseases such as psittacosis , salmonellosis , campylobacteriosis , mycobacteriosis ( avian tuberculosis ) , avian influenza ( bird flu ) , giardiasis , and cryptosporidiosis over long distances .