The death toll linked to listeria-contaminated cantaloupe in the United States rose to 29 as another death was reported, the Centers for Disease Control and Prevention said on Wednesday.
Whole or pre-cut Rocky Ford-brand cantaloupe from Colorado-based Jensen Farms has been traced as the cause of what has become one of the deadliest U.S. food-borne outbreaks in U.S. history.
A total of 139 people in 28 states have fallen ill so far in the outbreak, and the CDC has said that one woman, who was pregnant at the time she fell ill, had a miscarriage.
The deadliest known food-borne listeria outbreak prior to the current spate of illnesses in the United States was in 1985, when Mexican-style soft cheese contaminated with listeria was tied to the deaths of 18 adults, and 10 newborns, as well as 20 miscarriages, according to a CDC report.
Listeriosis has a long incubation period, with symptoms sometimes not showing up until two months after people consume tainted foods.
The elderly, pregnant women and people with weakened immune systems are most at risk of falling ill from listeria infection. Symptoms include fever and muscle aches, sometimes preceded by diarrhea and other gastric problems.
In a warning letter to Jensen Farms last month, the U.S. Food and Drug Administration said testing turned up widespread listeria contamination at its Granada, Colorado, packing plant, which "indicates poor sanitary practices in the facility".
Listeria outbreaks are most commonly linked to contaminated cheese or packaged meats. The current outbreak is the first to be associated with cantaloupe.
"What this shows is that these bugs are very opportunistic," food safety attorney and advocate Bill Marler said.
"As long as you have a cool, wet environment and a product that is ready-to-eat, you're always going to have a risk of listeria contamination, which is why the sanitation of the plant is so critical," said Marler, who is representing several families affected by the outbreak.
(Reporting by Lisa Baertlein; Editing by Cynthia Johnston)