The Health Protection Agency has confirmed that the salmonella strain, known as Salmonella Enteritidis Phage Type (PT) 14b, affected 262 people in England, Wales, Northern Ireland and the Isle of Man since the beginning of April this year. The majority of the cases were in North West England (111), the West Midlands (38), Yorkshire and Humberside (36) and the East Midlands (31).

The source of infection was traced to eggs from a specific shed on one farm in Spain. In the UK, the eggs were mainly supplied to catering establishments.

Liz Redmond, Head of Hygiene and Microbiology at the Food Standards Agency, said: "The FSA alerted environmental health officers and the implicated eggs were withdrawn. The issue was reported to the Spanish authorities who then took prompt action to tackle the problem at source. The eggs were destroyed or heat treated, the affected flock of hens have been culled and the shed has been cleaned and disinfected"

The number of new cases of Salmonella Enteritidis PT 14b reported to the HPA has dropped to the usual background levels, which indicates that the measures taken by the outbreak control team partners and the Spanish authorities were effective.

Dr Joe Kearney, an HPA director who chaired the outbreak control team that comprised the Health Protection Agency (HPA), the Food Standards Agency (FSA) and environmental health officers from a number of local authorities, said: "This was a detailed and thorough investigation by a number of agencies. We had full co-operation from the Spanish authorities, who took prompt action to eliminate the risk once the situation had been reported to them."