National case definition: Typhoid Fever

Date of last revision/review: December 2023.

National notification

Only confirmed cases of disease should be notified.

Type of surveillance

Routine case-by-case notification to the federal level.

Case classification

Confirmed case

Laboratory confirmation of infection with or without clinical illness:

• Isolation of Salmonella Typhi from an appropriate clinical specimen (e.g., blood, stool, urine, bone marrow, rectal swab, deep tissue wound, other sterile site, vomit).

Probable case

Clinical illness in a person who is epidemiologically linked to a confirmed case.

Laboratory comments

Further strain characterization (e.g., serotyping, whole genome sequencing [WGS]) is required for epidemiologic, public health, and clinical management.

Clinical evidence

Clinical illness may be characterized by the following signs or symptoms: Fever, diarrhea, headache, malaise, loss of appetite, splenomegaly, constipation, cough, tiredness, and/or rose-coloured spots on the abdomen or chest. Atypical presentations occur, and the severity of the illness varies. While not considered clinical illness, asymptomatic infections may occur.

ICD code(s)

ICD-11 code(s)

• 1A07 Typhoid fever

ICD-10 code(s)

• A01.0 Typhoid fever

Comments

Paratyphoid fever caused by Salmonella Paratyphi A, B and C is reported under salmonellosis.

Probable case definitions are provided as guidelines to assist with case finding and public health management, and are not for national notification purposes.