The Early History of Infectious Bronchitis

Two years later, Bushnell and Brandly (3) reported on an essentially identical disease. They established that the causative agent was a filterable virus because the disease could be transmitted by Berkefeld-filtered material. Because the symptoms of respiratory distress were caused by a filterable virus, Bushnell and Brandly regarded the disease as a form of infectious laryngotracheitis (LT). Further critical tests were not made to confirm this...