Typhoid fever is a disease of public health significance, according to the Health Protection and Promotion Act, R.S.O., 1990. All suspect and confirmed typhoid fever cases must be reported to the Health Unit as soon as possible.
XDR S. Typhi in Pakistan and Ontario
The outbreak of XDR S. Typhi in Pakistan has been ongoing since February 2018, with the majority of cases reported in Karachi and Hyderabad. As of December 2018, 5372 cases were reported. In the United States, five cases related to this outbreak were identified from 2016 to 2018.
A total of nine cases of XDR S. Typhi have been reported in Ontario residents as of May 6, 2019; the first case was identified in July 2018, with the two most recent cases identified the first week of May 2019. All cases had recently travelled to Pakistan. The majority reside in Toronto or Peel Region.
DIAGNOSIS OF TYPHOID FEVER
Clinical Evidence: Symptoms usually appear within 8 to 14 days of exposure. Symptoms include:
- Abdominal pain.
- Diarrhea (more common) or constipation.
- Rising fever with chills but frank rigors are rare.
- Relative bradycardia or pulse-temperature dissociation maybe observed.
- Rash with flat rose-coloured spots
- Loss of appetite
- Hepatosplenomegaly, intestinal bleeding and perforation may occur.
More serious cases may experience bacteremia with sepsis, gastrointestinal complications, and neurological complications (e.g., confusion and delirium).
- Inquire about travel to Pakistan and other areas in South Asia in patients with symptoms compatible with typhoid fever. Note that patients who have received the typhoid fever vaccine may still become ill, as the vaccine is 50-80% effective.
- Lab testing:
- Blood cultures and stool samples should be collected for bacterial culture and submitted to your local laboratory for routine testing. Please include travel history on requisition.
- In addition to routine susceptibility testing, all S. Typhi isolates from Pakistan should be tested for carbapenem and azithromycin susceptibility.
- All isolates of S. Typhi should be forwarded to the Public Health Ontario (PHO) laboratory for confirmation. Please include travel history and indicate if the isolate is XDR on the requisition. PHO will perform identification and full susceptibility testing including for azithromycin and carbapenems.
MANAGEMENT OF XDR S. TYPHI CASES
XDR S. Typhi is resistant to multiple antibiotics including chloramphenicol, ampicillin, trimethoprimsulfamethoxazole, fluoroquinolones, and third-generation cephalosporins. The strain associated with this outbreak is only susceptible to azithromycin and carbapenems.
Patients with suspected typhoid fever and a travel history to Pakistan should be empirically treated with azithromycin or carbapenems based on clinical presentation pending full antimicrobial susceptibility testing results. Do not use fluoroquinolones or ceftriaxone empirically for these patients. Consult an infectious disease specialist for patients with severe typhoid fever.
PATIENT EDUCATION: PREVENTION
- Advise patients who are planning to travel abroad to obtain a travel medicine consultation as early as possible before their trip, including an assessment of the need for typhoid vaccine.
- Counsel patients on following safe food and water practices and proper hand hygiene.
- Patients who are visiting friends and relatives are at higher risk compared to business travelers and tourists and should be counselled accordingly.
Our website (www.wechu.org) is a useful reference for health care providers. For additional information or consultation, please call the Health Unit during regular office hours @ 519-258-2146 ext. 1420.
- Government of Canada - Typhoid Fever:
- Public Health Ontario – Typhoid Fever: