14.04.2016

Six years of Iowa State University testing show a dramatic decrease in the number of environmental samples taken from egg facilities that test positive for the Salmonella enteritidis causing human food poisoning.
The Veterinary Diagnostic Laboratory in Iowa State’s College of Veterinary Medicine annually conducts tests on nearly 13,000 environmental samples. About 60 percent of the samples originate from Iowa egg farms and the remainder from sites located in more than a dozen other states.
The U.S. Food and Drug Administration requires facilities housing more than 3,000 laying hens, comprising more than 98 percent of the nation’s flocks, to take environmental samples during various stages of production. Environmental samples are taken from the surfaces of egg conveyor belts, floors and poultry manure to check for the presence of salmonella. Samples are submitted to the ISU lab to be tested for the salmonella bacterium.An analysis shows the percentage of environmental samples testing positive declined from 24.5 percent in 2010 to 2.5 percent in 2015. Potential reasons for the significant drop in positive samples may include an increase in flocks that are vaccinated for the salmonella bacterium.