State and local officials in Washington are investigating a deadly outbreak of Listeria infections.
Five patients had been identified to date. All five required hospitalization and three have died, according to the Tacoma-Pierce County Health Department.
All of the patients are or were in their 60s or 70s and all had weakened immune systems, according to the health department, which is working with the Washington State Department of Health (DOH) and Thurston County Public Health and Social Services.
The Tacoma News reports that “genetic fingerprinting (whole genome sequencing) results indicate that these patients likely have the same source of infection. The patients became ill between February 27 and June 30, 2023.”
State and local public health officials have not yet discovered a source of the bacteria. They are interviewing patients and their representatives to develop a profile.
Washington state typically sees 10 to 25 cases of Listeria infection annually, according to the Tacoma Health Department.
About Listeria infections
Food contaminated with Listeria monocytogenes may not look or smell spoiled, but it can still cause serious and sometimes life-threatening infections. Anyone who has developed symptoms of Listeria infection should seek medical treatment and tell their doctors about possible exposure to Listeria.
Symptoms of listeriosis can take up to 70 days after exposure to Listeria.
Symptoms of Listeria infection may include vomiting, nausea, persistent fever, muscle aches, severe headache, and stiff neck. Specific laboratory tests are required to diagnose Listeria infections, which can mimic other diseases.
Pregnant women, the elderly, young children, and people such as cancer patients who have weakened immune systems are especially at risk of serious illness, life-threatening infections, and other complications. Although infected pregnant women may experience only mild, flu-like symptoms, their infections can lead to premature birth, infection of the newborn, or even death.