A national outbreak of salmonellosis from yeast flavoured products.

A national outbreak of salmonellosis caused by a rare serotype occurred between July and November 1989. A total of 40 cases of Salmonella manchester infection were identified by the PHLS Division of Enteric Pathogens with a further 7 cases reported from Scotland. The median age of those affected was one year. All strains from the outbreak carried a 70mDal plasmid with a distinctive restriction endonuclease. A statistical association was found between infection and consumption of nationally distributed savoury corn snacks. Samples of autolysed yeast powder and flavourings used in the manufacture of many processed foods were also found to be positive for S. manchester.