A recent survey of raw flour and flour-based foods conducted by researchers at the UK Health Security Agency (UKHSA) found a low incidence rate of Salmonella and Shiga toxin-producing Escherichia coli (STEC) among sampled products; however, the finding does not negate the food safety risk posed by these pathogens in this food category, as whole genome sequencing (WGS) revealed a link between a Salmonella isolate from a flour-based food and a human case of salmonellosis.
In the UK, the Bread and Flour Regulations of 1998 define which ingredients are permitted in flour and bread, but do not require regular monitoring of the microbiological quality of flour and flour-based products. At the same time, previous studies carried out in Europe and North America have linked human Salmonella and STEC infections to flour products, and several foodborne illness outbreaks caused by these pathogens have been potentially linked to flour and flour-based foods in the U.S. and Canada within the last decade.