Salmonella
What is it?
Salmonella is a group of bacteria presenting one of the commonest causes of food poisoning in Great Britain. They can also cause typhoid and paratyphoid fevers. Salmonellosis has been recognised as an important zoonotic disease (one that can be transmitted from animals to humans) for many years. More than 2,500 different strains of Salmonella have been identified, most of which rarely cause disease. Human disease is caused by about ten strains -the most important are S. enteritidis (which originatesfrom infected poultry and eggs) and S. typhimurium Nwhich occurs especially in cattle, pigs and Turkeys).
History
Salmonella outbreaks have occurred throughout the last 100 years. By the 1990s, S. enteritidis infections from eggs had reached pandemic proportions.
Source
According to a 2007 report, nearly a quarter of chicken flocks reared for meat across Europe are infected with Salmonella. And around 10.3 per cent of pigs going to slaughterhouses across the EU test positive for Salmonella. Studies show that poor ventilation, high dust levels and overcrowding aid the spread of Salmonella among chickens. In 2009, the UK Health Protection Agency announced a three fold increase over the previous twelve months in the number of human Salmonella cases reported that year.
Symptoms in animals
When farmed animals, particularly poultry and pigs, become infected with Salmonella, they frequently become carriers of the Infection without showing signs of ill health. Nevertheless, infection may occasionally result in enteritis (inflamed small intestine), abortion, septicaemia, or death.
Symptoms in people
Symptoms include diarrhoea, stomach cramps and sometimes vomiting and fever. Salmonella can trigger an arthritic condition known as reactive arthritis, which causes painful and swollen joints.
Routes of transmission
Salmonella can be transmitted by contaminated food, usually of animal origin; faeces from an infected animal or person; and contact with infected animals. The most common sources of infection are poultry meat and eggs. Salad vegetables, spices and herbs, which may have been cross-contaminated with animal faeces, have also been implicated in large outbreaks of the infection.