LONDON – Public health officials in England are investigating an outbreak of Salmonella enteritidis that sickened 156 individuals. Salmonella enteritidis is sometimes linked to poultry or eggs.

Public Health England (PHE) reported 55 cases in Hampshire; 25 in London; 33 in Cheshire and 43 in the West Midlands. The cases in West Midlands were linked to Birmingham Heartlands Hospital where three people died. Two of the deaths were not related to the outbreak, according to hospital officials, and the third death remains under investigation. Thirty-two of the cases in Hampshire were linked to a Chinese restaurant, according to news reports.

Public health officials originally investigated the cases as individual clusters. But now PHE is investigating the possibility the cases are linked. Genetic testing of the bacteria revealed the strains were closely related, PHE said. The agency said it was too early in the investigation to name a single source, but food and environmental samples were taken at catering establishments; those samples tested positive for Salmonella with the same genetic profile.

“We are working with our colleagues across PHE, at the Food Standards Agency, in local authorities and with other public health organizations in Europe to investigate the cause of this outbreak," Dr. Paul Cleary, a consultant epidemiologist leading the PHE investigation, said in a statement. “We are making good progress and hope to have more conclusive evidence shortly.”

News reports also state that 49 individuals in France were sickened. The number of illnesses in Austria were unknown.