Psittacosis known serovars. All should be considered to be readily transmissible to humans. "C. psittaci" serovar A is endemic among psittacine birds and has caused sporadic zoonotic disease in humans, other mammals, and tortoises. Serovar B is endemic among pigeons, has been isolated from turkeys, and has also been identified as the cause of abortion in a dairy herd. Serovars C and D are occupational hazards for slaughterhouse workers and for people in contact with birds. Serovar E isolates (known as Cal-10, MP, or MN) have been obtained from a variety of avian hosts worldwide, and although they were associated with
Marek's disease evolution of Marek’s disease due to vaccination has had a profound effect on the poultry industry. All chickens across the globe are now vaccinated against Marek’s disease. Highly virulent strains have been selected to the point that any chicken that is unvaccinated will die if infected. Other leaky vaccines are commonly used in agriculture. One vaccine in particular is the vaccine for avian influenza. Leaky vaccine use for avian influenza can select for virulent strains which could potentially be transmitted to humans. Marek's disease Marek's disease is a highly contagious viral neoplastic disease in chickens. It is named after József