Psittacosis Europe in 1879. In 1929, a highly publicized outbreak of psittacosis hit the United States. Although not the first report of psittacosis in the United States, it was the largest up to that time. It led to greater controls on the import of pet parrots. The aftermath of the outbreak and how it was handled led to the establishment of the National Institutes of Health. From 2002 through 2009, 66 human cases of psittacosis were reported to the Centers for Disease Control and Prevention, and most resulted from exposure to infected pet birds, usually cockatiels, parakeets, and macaws. Many more
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