An outbreak of salmonella linked to Kinder eggs could have been caused by bad buttermilk in a Belgian factory, said European health officials on Tuesday.
At least 150 children have been taken ill in nine countries across the continent since the first case was identified in Britain in December.
The European Centre for Disease Prevention and Control and the European Food Safety Authority said they had matched the same salmonella strain currently infecting people to samples taken from a factory in Belgium that same month.
Officials said “the processing step involving buttermilk” was identified as the point of contamination for two products, the surprise chocolate eggs with a toy inside and praline chocolates.
“This outbreak is rapidly evolving, and children have so far been most at risk for severe infection among reported cases," the European CDC said in its report.
It noted further investigation was needed to determine how the problem happened and evaluating "the possibility of the wider use of contaminated raw material in other processing plants.”
On Friday, Ferrero, the company behind the chocolate products, announced a widened recall of its Kinder line products in the UK manufactured at its Arlon site in Belgium since last June.
A previous recall only covered products with best-before dates up to October, 7 2022.
Kinder Surprise, Kinder Mini Eggs, Kinder Surprise 100g and Kinder Schokobons are among the products affected.
The Food Standards Agency said it was continuing to investigate the salmonella outbreak.
Its head of incidents Tina Potter said: “We continue to work closely with UK and international partners, including the UK Health Security Agency and Food Standards Scotland, to establish how this outbreak started and make sure all necessary steps have been taken to prevent further illness.”
As of this week, 150 cases of salmonella have been reported in nine European countries, with the majority reported in children under the age of ten.
“An exceptionally high number" have been hospitalised, European officials said.
At least 67 people have been affected in the UK, according to the UK Health Security Agency, with the majority of those aged under five.
Salmonella symptoms include diarrhoea, fever and stomach cramps.
Most people who get sick do not need any medicine but some severe cases may result in hospitalisation.
Ferrero has previously said it is cooperating with all the relevant authorities in the outbreak investigation.
"We are taking this extremely seriously as consumer care is our top priority," the company said.
