EFSA calls for new safety measures after deadly E.coli outbreak

The agency called for tougher procedures to cut the risk posed by shiga-toxin producing E.coli in sprouted seed (sprouts, shoots and cress) as it delivered its verdict following outbreaks in Germany and France that killed 50 and sickened over 4,000.

Experts from the food safety watchdog declared that sprouted seeds present heightened safety concerns as they are usually eaten raw or after minimal processing. Pathogenic bacteria are able to contaminate seeds and grow during sprouting, said the body’s panel on Biological hazards (BIOHAZ).

The group noted that sprouts had been linked to previous outbreaks. They were most commonly caused by Salmonella and E.coli pathogens – sometimes at the very low levels of just four bacteria/kg in seeds for sprouted products.

Risk factors​

Seed contamination can happen in a raft of ways – both in production and processing, said the panel.

Key risk factors in production centre on agricultural practices, storage and distribution – with contaminated irrigation water and/or manure, the presence of birds and rodents in storage facilities all posing risks. Dust and soil particles are also potential hazards, said EFSA.

Processing conditions – such as temperature and humidity – that exist during germination and sprouting of contaminated seeds can boost the growth of pathogens and “should be considered as major risk factors”​, added BIOHAZ.

Poor traceability of seed lots is a further issue which can lead to a delay in action taken by health authorities and prevent producers pinpointing which seed batch may be contaminated. The widespread distribution of seed lots can also increase the size and geographical spread of an outbreak.

False sense of security​

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In examining the use of microbiological testing as a solution, EFSA said major challenges existed as methods to detect emerging pathogens in sprouts and seeds “may not yet exist or be applied”.​

A lack of information on the risks factors during production means laying down of hygiene methods has been difficult, said the panel as it called for more data collection on the matter.

“Microbiological testing alone may convey a false sense of security due to the statistical limitation of sampling plans,”​ added the report. “A negative sample result does not ensure the absence of the pathogen in the tested lot, particularly where it is present at low or heterogeneous prevalence. It is currently not possible to evaluate the extent of public health protection provided by specific microbiological criteria for seeds and sprouted seeds.”​

The agency outlined options to mitigate the risk – including the implementation of HACCP principles by operators throughout the production chain.

“The hazard analysis should include risk classification of commodities, regions of origin, and operators and suppliers of seeds,”​ said BIOHAZ.

But it noted that in seeds it can be difficult to define critical control points (CCPs) including hazard control measures, critical limits and monitoring in seed production and, to some extent, in sprout production.

While decontamination of seeds is practiced in some EU states, the panel said no method of decontamination was currently available to ensure elimination of pathogens in all types of seeds without affecting seed germination or sprout yield.

EFSA said the safety and efficacy of different seed decontamination treatments – such as chemical, heat treatment, irradiation alone or in combination - should be examined on an EU level.

It also suggested the introduction of a chill chain for sprouts and shoots from end of production to consumption is necessary to limit growth of bacterial pathogens.