Salmonella

Description

Salmonella is a type of bacteria that typically live in the intestinal tract of animals. Salmonella can cause diseases in humans and other animals and is the bacteria responsible for the disease salmonellosis. Salmonellosis in warm-blooded animals is most often caused by strains (serovars) of Salmonella enterica subspecies enterica.

The most common type of salmonellosis is where animals carry the bacteria for a period but do not show signs of disease, which is known as the carrier state. When animals do show signs of disease, there are two major syndromes:

• Inflamed intestines (enteritis)
• Blood poisoning (septicemia)

Other syndromes exist, such as: 

• abortion
• arthritis
• meningitis
• necrosis of extremeties
• respiratory disease

Naming conventions

Salmonella strains are most often referred to by their abbreviated names. For example, Salmonella enterica subspecies enterica serovar Dublin is most often known as Salmonella Dublin or simply S. Dublin.

Different strains and their impacts

Only a few strains of Salmonella bacteria produce visible disease in healthy humans and animals. For example, Typhoid Fever or similar diseases are caused by the following strains:

• Salmonella enterica subspecies enterica serovar Typhi (S. Typhi) is responsible for Typhoid in people
• Salmonella enterica subspecies enterica serovar Gallinarum (S. Gallinarum) causes a similar disease in poultry
• Salmonella enterica subspecies enterica serovar Dublin (S. Dublin) causes a similar disease in cattle.

Other strains rarely produce visible disease in healthy, adult, nonpregnant animals; however, the Salmonella bacteria may still be present in the intestines. This presence can lead to: 

• Salmonella exposure of humans (like farm workers) interacting with the animals or the contaminated environment
• contamination of food during processing or preparation
• subsequent ingestion of contaminated food due to inadequate cooking temperatures or other factors 

Salmonella in Humans

Salmonella bacteria are the most common organisms detected in human cases of gastroenteritis. For more information on salmonellosis in people see:

• Government of Canada’s Salmonella website
• Public Health Agency of Canada’s National Enteric Surveillance Program website. 

For information on Salmonella outbreaks in people, see the Public Health Agency of Canada’s website at:

• Public Health Notices.

Salmonella in Livestock

There are more than 2,500 Salmonella strains, but common strains associated with livestock are:

Reportable and notifiable Salmonella strains

In Alberta, Salmonella strains are categorized either as:

• Reportable category - May trigger a disease investigation
• Notifiable category - Information collected for surveillance purposes

Salmonella strains in the reportable category are:

• S. Enteritidis, Typhimurium, and Heidelberg in: 
  • Domestic chickens, bantams, pheasants, and peafowl
  • Domesticated ducks and domesticated geese
  • The following birds when kept in captivity: domestic turkeys, wild turkeys, ostriches, emu, rheas, pigeons, doves, quail, and guinea fowl
• S. Gallinarum and Pullorum in: 
  • Domestic chickens, bantams, pheasants, and peafowl
  • The following birds kept in captivity: domestic turkeys, wild turkeys, ostriches, emu, rheas, pigeons, doves, quail, and guinea fowl
• S. Dublin and Typhimurium in: Cattle and yaks.

All other strains are in the notifiable category.

Resources

For a breakdown of ALL reportable diseases by species, see:

• Reportable and Notifiable Diseases reference card.

Contact

Connect with the Office of the Chief Provincial Veterinarian:

Hours: 8:15 am to 4:30 pm (open Monday to Friday, closed statutory holidays)
Phone: 780-427-3448
Toll free: 310-0000 before the phone number (in Alberta)
Fax: 780-415-0810

Address:
O.S. Longman Building
6909 116 Street NW
Edmonton, Alberta  T6H 4P2