Summary of cereulide contamination in infant formula
- Cereulide contamination triggered major infant formula recalls across leading manufacturers
- The toxin causes rapid vomiting and on rare occasions, worse
- Cereulide forms when Bacillus spores germinate under specific environmental conditions
- Contamination likely originated from ARA oil supplied by unidentified third party
- Recalls deemed precautionary since low cereulide levels may pose minimal risk
Until very recently, few people had heard of cereulide. But in a matter of weeks, it has become one of the most talked-about toxins – and for troubling reasons. Cereulide is at the centre of a series of infant formula recalls following suspected and, in some cases, confirmed contamination.
So what exactly is cereulide? And crucially, how does a toxin like this find its way into the infant formula supply chain?
What is cereulide?
Cereulide hit the headlines amid concerns the toxin had contaminated infant formula products made by big names in the business, including Nestlé, Danone and Lactalis. Precautionary recalls followed. A small number of infant illnesses – including two deaths – were reported as potentially linked, though no definitive connection to the contamination has been established.
National food safety agencies have helped manufacturers raise the alarm, recalling specific product lots and advising parents and caregivers not to feed the implicated batches to babies.
That’s because cereulide can cause nausea and vomiting – usually within 30 minutes to six hours. Symptoms typically last around 24 hours, but in cases where high concentrations of cereulide are consumed, the health impacts can be more serious: ranging from liver to kidney damage, and on rare occasions, death.
How does cereulide form in food?
Cereulide is produced by certain bacteria of the Bacillus cereus group. The bacteria are known to form very stable persistent forms, or spores. And actually, these are prevalent in food; at low concentrations, they’re not a problem.
But if the spores germinate, and the bacteria multiply, it can lead to the development of cereulide in food. As the German Federal Institute for Risk Assessment explains, for cereulide to form, specific environmental conditions need to align: the bacteria need suitable moisture content, pH value, salt content, available nutrients, absence of competing microorganisms and storage temperature.
If cereulide can only develop under very specific conditions, the obvious question is: how does it enter the infant formula supply chain?
The low water content of powdered infant formula does not support cereulide formation. In dry form, cereulide cannot develop. This means cereulide is not being created within the formula powder itself, but likely via an ingredient supplied by a third party.
The unidentified ingredients supplier
That checks out with the manufacturers in question, who are linking potential contaminations with arachidonic acid (ARA) oil supplied by a third-party. The oil is added to infant formula to support brain and retina development.
The next question, therefore, is how does cereulide end up in ARA oil? It’s not immediately obvious, suggests Marcel Zwietering, professor in food microbiology at Wageningen University in the Netherlands. Like dried infant formula, oil doesn’t offer optimal conditions for the bacteria to grow.
The fact that the toxin was found does not directly prove negligence, but does show an out of control situation.
Prof Marcel Zwietering, professor in food microbiology, Wageningen University
The most likely scenario is that during, or even before the oil was produced, the organism had been growing and producing the toxin, he explains. “It might not form easily in oil, but it could readily dissolve in oil – since it’s lipophilic."
So, who is this third-party? No manufacturer is saying very much. Nestlé describes the company as a “global industry supplier”, confirming it has discontinued sourcing from that company. According to the Food Safety Authority of Ireland, the contaminated oil was manufactured in China, and Lactalis told Reuters it was sold by a Dutch company – but it isn’t Amsterdam-listed dsm-firmenich.
Though speculation is growing, the third‑party supplier has still not been identified.
Contamination detected, but negligence not proven
Just because infant formula brands have recalled batches does not mean we’re in “scandal” territory. There is no generally accepted safe level of cereulide in infant formula products, and guidance from the European Food Safety Authority (EFSA) states there should be “no detectable level” of cereulide in infant formula products. However, very low levels of cereulide might not give symptoms.
If levels are low, and the amount of ARA in the final product is minor – as little as 15mg per 100ml – the amount of cereulide could be miniscule, explains prof Zwietering. “But, whether dangerous levels are reached depends on the levels of the ARA and then also the dilution of the total product.”
The fact is, outbreaks happen. And the source is not always obvious. Sometimes outbreaks occur, cause illness, and then is the source of the contamination is identified, like what happened when botulism was linked to infant formula brand ByHeart in the US last year.
But in the case of cereulide, the toxin was identified before any illness was reported. Yes, reporting of illnesses have since followed, but haven’t been confirmed as linked to the contamination.
Prof Zwietering agrees with the decision to recall given the formula is intended for infants – an extremely vulnerable population. But he isn’t convinced negligence is at play; ARA is not considered a high risk product for cereulide. “Still, testing was done and the ARA producer should have good hygiene and a hazard analysis and critical control point (HACCP) plan.
“The fact that the toxin was found does not directly prove negligence, but does show an out of control situation.”
