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Salmonella

What is salmonella?

Salmonella are gram-negative human and animal pathogens and can be subdivided into over 2500 types. Salmonellosis, a disease diagnosed in over 10,000 people in the UK each year, is common throughout the world.

Clinical signs in animals

Salmonella can occur in all species of domestic animal and manifests mainly as diarrhoea although clinical signs also include septicaemia, abortion, arthritis and respiratory disease.

Many healthy animals can also carry the organisms in their intestinal tract and may be important in the spread of infection between animals, into the environment and into the food chain.

A Guide to the National Control Programme for Salmonella in Laying Flocks is available on the Defra website.

Clinical signs in humans

People are infected by eating contaminated food or by contact with faeces from infected people or animals. Illness is characterised by watery and sometimes bloody diarrhoea, abdominal pain, fever, headache, nausea and vomiting.

The predominant serovars (types) isolated from people are S. Typhimurium, S. Enteritidis, S. Infantis, S. Hadar and S. Virchow.

Surveillance at VLA

The VLA provides veterinary and clinical laboratory expertise. Approximately 10,000 salmonella isolates are examined each year and results are published in the annual publication; Salmonella in Livestock Production.

In addition, field investigations at farms are undertaken for confirmation of infection by sampling, clinical examination of affected stock, collection of epidemiological data and provision of advice on control of infection.

Research at VLA

Research studies include microbiological input to epidemiological investigations of the distribution, persistence and control of salmonella in cattle, pig and commercial egg laying farms.

The VLA has a long history of development and evaluation of salmonella vaccines for poultry and latterly pigs in collaboration with commercial partners.

Reference Laboratory status

The VLA is a holder of the World Organisation for Animal Health (OIE) and UK National Reference Laboratory status for salmonella.

EU broiler survey 2008

The European Food Safety Authority has published the results of a survey on Campylobacter and Salmonella in chicken at slaughterhouses in the European Union.

Training and guidance on Salmonella in pigs for veterinarians in private practice

AHVLA and BPEX are holding three regional training events in November 2011 for veterinarians with an interest in pig health, well-being and welfare. See the Control of Salmonella in pigs page which has more details of these events, plus downloadable guidance leaflets from AHVLA on on-farm Salmonella control.