Public Health England (PHE) reported Aug. 15 that it is investigating a national outbreak of a type of Salmonella enteritidis that has affected 156 people.

To date, PHE officials said, 55 cases have been seen in Hampshire, 25 in London, 33 in Cheshire and Merseyside, and 43 in the West Midlands. Cases originated in Cases have also been reported in Austria and France.

In England, the cases occurred as isolated clusters over several months and have been managed locally, but are now being reassessed as potentially linked under a national investigation.

Paul Cleary, a consultant epidemiologist leading the PHE investigation, said: “We are working with our colleagues across PHE, the Food Standards Agency, in local authorities and with other public health organizations in Europe to investigate the cause of this outbreak."

He added, “We are making good progress and hope to have more conclusive evidence shortly. We will continue to monitor the situation and if there is any further public health action necessary then we will ensure that this takes place.”

According to a PHE press release, testing using genetic typing methods has revealed that all of the affected persons are infected with closely related strains, indicating that the cause of the illness is from a single source. Some food and environmental samples from catering outlets -- reported by the London Evening Standard to include a Chinese restaurant and a hospital -- have tested positive for Salmonella with the same genetic profile seen in the outbreak cases.