Sprouts may sound like it, but the small greens that are sick more than 2,500 people and caused 186 hospital admissions and three deaths in the past two decades, a new report finds.
“Sprout contamination continues to pose a serious public health problem,” the researchers from the Food and Drug Administration (FDA) wrote in their report. The arm of the FDA that wrote the new report focuses on the investigations of outbreaks and find ways to prevent them. The findings about the sprouts were presented on Oct. 28 at IDWeek 2016, a meeting in New Orleans of several organizations that focus on infectious diseases. The report on the sprouts is not published in a peer-reviewed journal.
From 1996 to August 2016, 48 outbreaks of disease were associated with sprouts, the researchers found.
Alfalfa are the most common culprit during the study period, with 30 outbreaks. There were seven outbreaks linked to clover sprouts, six outbreaks associated with mung bean sprouts, two outbreaks associated with unspecified brussels sprouts and two outbreaks associated with multiple sprout types and an outbreak linked to a food ingredient called sprouted chia powder, the FDA found.
Sprouts wore a number of different types of bacteria, the researchers found. Salmonella was involved in the largest number of outbreaks, at 35, followed by Escherichia coli (11 outbreaks) and Listeria monocytogenes (two outbreaks), according to the report.
Of the three sprout-related deaths in the study period, two were attributed to Salmonella and one for Listeria.
Sprouts “certainly rank up there” among the types of products that are linked to outbreaks, said Dr. Kathleen Gensheimer, director of the FDA’s Coordinated Outbreak Response and Evaluation Network, and the lead author of the study.
Sprouts’ tendency to harbor dangerous bacteria has to do with how they are grown, Gensheimer told Live Science. To grow sprouts, the seeds are placed in water in a warm, moist environment that is ideal for rapid growth of bacteria, ” she said.
That means that if a seed is infected with bacteria before the sprouts are grown, the problem becomes even worse during the sprouting process, because the bacteria multiply, Gensheimer said. Indeed, in most sprout outbreaks, the outbreak arose from seeds that had been contaminated with bacteria before the sprouting process began, she said. Bacteria on a seed when it is harvested and can survive for months in dry conditions in which the seeds are stored, ” she said.
Alfalfa, the most common source of an outbreak in the study, are the most popular form of green seed sprouts that are typically eaten raw, Gensheimer said. Sprouts from green seeds such as alfalfa, clover sprouts and radish sprouts, are not usually cooked before they are eaten, and thus they are more often associated with outbreaks. In contrast, the sprouts come from beans, such as mung bean sprouts and soy bean sprouts, usually cooked, she added.
Thoroughly cooking sprouts can reduce a person’s risk of getting sick, because cooking can kill the harmful bacteria, Gensheimer said.
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But sprouts can be a “stealth fabric,” Gensheimer added. They are the type of substance that can be added to a sandwich or a salad in a restaurant or deli without having to be listed, ” she said.
Currently, the US government says that the people who are most at risk for infectious diseases should avoid eating raw or lightly cooked sprouts of any kind, Gensheimer said. This includes children, the elderly, pregnant women and people with weakened immune systems, she said.
Originally published on Live Science.