For health professionals: Salmonellosis (Salmonella)

Find detailed information on salmonellosis for health professionals.

On this page

• What health professionals need to know about salmonellosis
• Clinical manifestations
• Diagnosis
• Treatment
• Salmonellosis surveillance in Canada
• For more information

What health professionals need to know about salmonellosis

The genus Salmonella is a member of the family Enterobacteriaceae. There are 2 species of Salmonella:

1. Salmonella enterica
2. Salmonella bongori

The Salmonella enterica species is subdivided into 6 subspecies:

1. enterica (I)
2. salamae (II)
3. arizonae (IIIa)
4. diarizonae (IIIb)
5. houtenae (IV)
6. indica (VI)

The enterica subspecies of Salmonella enterica has at least 2,610 different serotypes. 

Salmonella serotypes can be divided into 2 broad classes:

1. typhoidal Salmonella, which refers to the specific Salmonella serotypes that cause typhoid fever or paratyphoid fever, including:
   • typhi
   • paratyphi A
   • paratyphi B
   • paratyphi C
2. non-typhoidal Salmonella, which refers to all other serotypes

The National Enteric Surveillance Program annual report:

• lists all the serotypes reported in Canada each calendar year
• highlights those most commonly reported

Clinical manifestations

Salmonella enterica can cause 4 different clinical manifestations:

1. gastroenteritis
2. bacteremia
3. typhoidal fever
4. an asymptomatic carrier state

Fecal shedding of Salmonella usually continues for several days or weeks beyond the acute phase of illness. Administration of antibiotics may not decrease this length of time.

Diagnosis

Confirm diagnosis by:

• isolation or culture identification from stool or blood
• serotyping to identify the serotype

Non-typhoidal Salmonella infection

Diagnosis of non-typhoidal Salmonella infection is carried out through culture.

In the case of acute gastroenteritis, stool specimens should be collected and sent to a local laboratory for testing.

If non-typhoidal Salmonella bacteremia is suspected, blood cultures should be collected and sent to a laboratory for testing. Serology doesn’t provide adequate information for diagnosis of infection.

Asymptomatic infections

To identify asymptomatic infections, fecal material should be inoculated into an appropriate enrichment medium. Specimen collection should be carried out over several days, as excretion of Salmonella organisms may be intermittent.

Treatment

Treatment depends on the clinical symptoms presented by the patient. Consultation may be required with an infectious disease specialist to determine the most appropriate treatment.

Gastroenteritis

The usual treatments for gastroenteritis symptoms are:

• control of nausea and vomiting
• fluid and electrolyte replacement

Antibiotic treatment is not usually used. However, it may be necessary for:

• neonates
• children
• the elderly
• the immunosuppressed

Bacteremia

Antibiotic treatment is used to treat bacteremia, especially for:

• neonates
• children
• the elderly
• the immunosuppressed

Typhoidal fever

Antibiotic treatment is used to treat typhoidal fever.

Asymptomatic carrier state

People in occupations with a high risk of transmission to others can also be treated with antibiotics. This will reduce the spread of the infectious agent. High-risk occupations include food handlers and daycare workers.

Salmonellosis surveillance in Canada

Salmonellosis is a nationally notifiable disease. Health professionals are to report cases to their provincial or territorial public health authorities.

Health professionals in Canada play a critical role in identifying and reporting cases of salmonellosis. See the surveillance section for more information on surveillance in Canada.