WIREDGOV

A multi-agency investigation established a link between a batch of imported eggs and an outbreak of Salmonella Enteritidis Phage Type (PT) 14b infection in England and Wales.

One hundred and 74 cases of Salmonella Enteritidis PT 14b infection have been reported since the beginning of this year, the majority being in North West England (77 cases) and the West Midlands (35 cases).

Dr. Joe Kearney, a director with the  HPA and chairman of the outbreak control team (OCT), said: "A strain of Salmonella Enteritidis PT 14b that was indistinguishable from samples taken from human cases was isolated from a small number of eggs that carried the same batch number.

"The batch number indicated that the 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 that source, including the culling of an implicated flock of hens, the cleaning of the shed and heat treatment of eggs to kill any Salmonella that may have been present.

"No eggs with the implicated batch number have been imported to this country since the end of June. The FSA alerted Environmental Health Officers (EHOs) in England and Wales to the situation, checks were made and continue to be made on the distribution chain and implicated eggs that were found to be still in the system were withdrawn from sale.

"We expect that these developments will have a significant impact in curtailing the outbreak, but in the meantime our investigations are continuing."  

Notes for editors

Press release issued by the Communications Department, HPA North West. Tel. 0844-2251295 and select option 2.

Salmonella can cause watery and sometimes bloody diarrhoea, abdominal pain, headache, nausea, vomiting, and fever. It is often associated with eating foodstuffs (most commonly red and white meats, raw eggs, milk, and dairy products) that have been contaminated with the bacterium.

Some foods contain the bacterium and need to be cooked before consumption. Other foods may become contaminated directly or indirectly as a result of poor storage or preparation, for example by storing raw and cooked products together or by using the same knives and chopping boards for the preparation of raw meat and foods that do not need to be cooked, such as salad vegetables.

Person-to-person spread, usually during the acute diarrhoeal phase of the illness, and contact with infected animals can also cause infection.

The illness can range from mild to severe. The elderly, infants, and those with impaired immune systems are more likely to have a severe illness. In some cases, the salmonella infection may spread from the intestines to the blood stream, and then to other body sites and can be fatal without treatment. However, death from salmonella infection is rare.

Treatment

The majority of patients do not require specific treatment and make a full recovery. Recovery is aided by a replacement of fluids. The advice of a health professional should be sought in cases of severe diarrhoea.
In rare events when infection spreads from the intestines to the blood stream, prompt hospital treatment is required.

Minimising impact

The Health Protection Agency undertakes surveillance of salmonella to provide timely reporting of sporadic cases, detection and containment of outbreaks and to identify trends in the rates of infection over time.

How common is it?

Rates of salmonella in the UK have fallen dramatically in recent years from a peak of infection in 1997. There are many reasons for this including greater public awareness about food safety. The compulsory vaccination of UK British Lion egg-laying flocks against Salmonella Enteritidis, which was introduced in 1998, has been a major factor.

As many people with salmonella do not seek medical treatment for their illness, the number of reported cases will be less than the actual number.

Prevention

Salmonella can be prevented by the correct storage and cooking of foods and safe and hygienic food handling and preparation. Avoidance of certain foods, for example unpasteurised milk and dairy products and raw eggs will also lower the risk of illness.

Thorough hand-washing is essential in infection control, particularly before eating or preparing food, after handling raw meat or poultry, after using the toilet, after changing nappies and after cleaning up after others with diarrhoea. Hand-washing after contact with domestic or farm animals is also vitally important.

Advice on the safe preparation, storage, cooking and handling of food is available from the Food Standards Agency website - www.food.gov.uk.