Two hundred and twenty-one cases of Salmonella Enteritidis PT 14b infection have been reported since the beginning of this year, the majority of cases being in North West England (104 cases), the West Midlands (36 cases) and the East Midlands (26 cases).

Dr Joe Kearney, a Health Protection Agency (HPA) director who chairs the outbreak control team (OCT), said: "A strain of Salmonella Enteritidis PT 14b that is indistinguishable from samples taken from the human cases was isolated from a small number of eggs that had the same batch number.

"These eggs had come from a specific shed on one farm in Spain. The Food Standards Agency (FSA) alerted the Spanish authorities and measures were taken to eliminate the risk of contamination from this source, including the culling of a flock of hens, the cleaning of the shed and the heat treatment of eggs to kill salmonella.

"No eggs with the implicated batch number have been imported to this country since the end of June. The FSA alerted Environmental Health Officers throughout England and Wales to the situation and checks were made and continue to be made on the distribution chain. Whenever eggs with the implicated batch number are found in the system, these are removed from sale. In the meantime our investigations are continuing," said Dr Kearney.