Three people have died and two others have survived after suffering severe listeria infections in Washington state, health authorities said in a statement released Friday.
All of the infected patients were older than 60 and had weakened immune systems, the Washington Department of Health said in a statement on Friday. They were all hospitalized.
Four patients were treated in Pierce County, home to the state’s third-largest city, Tacoma, and one in adjacent Thurston County, according to state health officials.
Although genetic fingerprinting, known as genome sequencing, helped health professionals conclude that the infections most likely had the same origin, the department has not yet been able to trace the outbreak to a common food source, according to the department.
The bacteria can be found on surfaces where food is prepared, unpasteurized fresh cheese, green leafy vegetables and sausages, as well as raw milk.
Although healthy people temporarily experience fever, muscle aches, nausea, abdominal pain, and diarrhea, Listeria monocytogenes can be deadly for pregnant women, those over 65, and people with compromised immune systems.
The bacteria are easily killed by heating food to 165 degrees or higher.
In July of last year, the US Centers for Disease Control and Prevention (CDC) announced 22 hospitalizations and one death from a multi-state listeria outbreak.
This article was originally published in English by Dennis Romero for our sister network NBCNews.com. For more from NBC News enter here.
