Dealing with, testing and reporting salmonella

Published on : 30 Aug 2022

Since its launch in 1998, the cornerstone of the Lion Code of Practice has been food safety, designed to ensure that British eggs remain the safest in the world.

The ‘Salmonella in eggs’ crisis 31 years ago taught the egg industry an important lesson. Since then BEIC has been determined to ensure that Salmonella in laying flocks is controlled. This has been achieved by putting in place a stringent set of standards across the whole production chain, starting at breeder level, through to packing centres and, via a separate code of practice, to egg products.

The key points of the Lion Code are:
Registration and traceability of hens, eggs and feed – this is achieved via the BEIC database which holds details of all Lion registered sites, by system of production, numbers of birds and hatch date. The ‘Lion passport’ is a particularly useful document which includes all the necessary details to ensure traceability from hatch to depopulation.

Vaccination against Salmonella Enteriditis, Salmonella Typhimurium and monophasic Salmonella Typhimurium
Without doubt one of the major cornerstones of the Lion Code is the requirement for every commercial hen to be fully vaccinated against Salmonella, using a vaccine that has a current UK marketing authorisation. We are fortunate in the UK that there are several products available, both live and inactivated, providing the producer and his/her rearer with choice. 

Proper rodent control
Another critical area of the Lion Code is to properly control rodents on farms. History has shown that rodents can recycle infection from one flock to another (so-called horizontal transmission), therefore ensuring that farms have in place an effective baiting and control programme, that is carefully monitored, is vital.

Hygiene, time and temperature controls
The Lion Code requires that high standards of hygiene and biosecurity are in place. Eggs must be collected from farm every third working day. Whilst on farm, and after removal from where they were laid, eggs must be stored at no more than 20oC. With rising summer temperatures, egg stores on laying sites must have some means of keeping eggs cool, to maintain quality and food safety.

Feed controls
All feed that is produced for Lion birds must be to the UFAS standard. This requires strict controls over raw materials, straights, and vitamins and minerals. 

Enhanced Salmonella testing
In addition to the sampling requirements of the UK National Control Programme, the Lion Code requires post cleaning and disinfection swabbing, including contact surfaces and rodent faeces/bait boxes. This is aimed at providing the operator with confidence that the C&D process has been effective.

Independent auditing
Our accredited monitoring agency is NSF International, operating to ISO17065 accreditation. The Lion Code also requires 6 monthly self-audits of all sites. In January 2019 we introduced the requirement that the Subscriber - be it a packer, breeder, pullet rearer, or feed mill – must accompany the senior manager of the site during both the 6-monthly self-audits. The NSF audit takes place independent of the 6 monthly self-audit cycle. To further enhance the audit process, in January 2019 BEIC increased the proportion of unannounced audits to 10% of all laying farms.

Reporting of Salmonella
The Lion code requires that any isolation of non-vaccinal Salmonella Enteritidis, Typhimurium or monophasic Typhimurium from the laying flock, or its environment, must be immediately reported to the BEIC. If an exotic Salmonella serovar other than SE, ST or mST should be isolated from the laying flock or its environment, veterinary advice must be sought and acted upon.

Actions in event of a positive
If, in the unfortunate event that a site should be notified that non-vaccinal SE, ST or mST has been identified, a strict protocol would be initiated under the Lion Code.

There are two separate courses of action - one by government and the other by Lion. As far as government is concerned, a notice is served on the affected flock requiring eggs to heat treated i.e. become Class B. The producer can opt for one of the three so-called confirmatory tests (Commission Regulation (EC) No 1237/2007) – enhanced environmental, 300 carcasses, or 4,000 eggs. Only if this test proves negative can eggs regain Class A status again and restrictions on the flock be lifted.

BEIC action requires that the flock be immediately suspended from the Lion scheme. BEIC would contact the producer to explain what happens next and to explain the producer’s options going forward. A BEIC appointed veterinarian would visit the site to take samples of the environment and eggs in all houses on site, and to carry out a thorough review including vaccination of the pullets and details of other parts of the supply chain.

When results are known, this would determine actions required and the producer would be able to decide what action best suits their business. If it is an older flock that is infected, often the decision would be to depopulate, noting that a further negative test would be required on the neck flaps of a randomly selected sample of birds to allow them to go to a processor, otherwise it could be slaughter on farm and the carcasses sent for rendering.

Bearing in mind that the removal of any residual infection is vital, BEIC would advise that, if possible, delivery of the new pullet flock be delayed, especially if a tight turnaround was planned, as it would be important to allow sufficient time for a longer than normal C&D of the site. Once C&D of the house(s) has taken place, a BEIC appointed veterinarian would return to resample across all areas of the house (50 samples). Only if these tests are negative can restocking take place and the site reinstated into the Lion scheme. It should also be remembered that APHA will take an official sample of the replacement pullet flock between 22-26 weeks. If this were to be positive, it could be a financial disaster for the producer, hence why it is considered vital to allow enough time to carry out a really good C&D.

Clearly, this would be a stressful time for any producer who is unfortunate enough to be in this situation. Should it occur BEIC would seek to ensure that the parties involved are kept up to speed with options as well as providing a point of contact. One area that producers may wish to consider is taking out insurance cover should they be unfortunate to be affected.

Looking to the future, several amendments will be added to the Lion Code to strengthen Salmonella control, which will be published in version 8 later this year. This includes other parts of the supply chain. We are also carrying out a research project looking at vaccine protection in older flocks. All this is designed to ensure that industry, our customers and consumers continue to have confidence in the Lion Code.