Production of Bacterial Aerosols in a Rendering Plant Process

Abstract

DURING AN OUTBREAK of ornithosis in the area of Portland, Oreg., approximately 60 people were infected with the virus between February 15 and March 15, 1956.Two deaths occurred.The source of the disease was determined to be infected turkeys from two ranches a few miles northwest of Portland.On these ranches, a large number of birds had died of unknown cause just prior to, and during, this period.The cause was later found to be ornithosis.Several hundred of these ornithosis-infected turkeys were processed by an animal-rendering plant on the northern outskirts of Portland be- tween January 1 and March 9, 1956.During this period, part of the plant's normal staff of 18 persons became ill with what was thought to be influenza or some other nonspecific respiratory infection and more people were either hired or borrowed from a nearby plant.A total of 32 different persons worked in the plant in the 10-week period during which the turkeys were processed.The investigation in- dicated that 24 employees showed symptoms of ornithosis (1).Some of these people were under hospital treatment as late as March 22, 1956.Serologic investigation revealed that 25 of 30 tested had an antibody titer against orni- thosis antigen.Dr.