Posted April 22, 2021. Past health advisories and alerts are archived for historical purposes and are not maintained or updated.
The Spokane Regional Health District (SRHD) identified an outbreak of enteric (typhoid) fever caused by Salmonella enterica serotype Typhi. Three patients have culture-confirmed infections. The patients’ ages range from 12 to 37 years and illness onset dates range from March 24 to March 29. The investigation is ongoing, but consumption of foods served at a local event is a suspected source of this outbreak.
Typhoid fever is a bacteremic illness caused by ingestion of Salmonella Typhi (typhoid fever) or Salmonella serotype Paratyphi (paratyphoid fever) and is transmitted through a fecal-oral route. While most cases reported in the United States occur among travelers to endemic areas of the world, transmission in the United States still occurs, commonly through food prepared by symptomatic or asymptomatic persons shedding the organisms in their stool.
Symptoms of typhoid fever can vary widely, but the most common symptoms are fever, chills, and abdominal pain. Other symptoms can include headache, malaise, myalgias, and constipation (more common in adults) or diarrhea (more common in children), nausea, and loss of appetite. A transient, maculopapular rash of rose-colored spots may be present on the trunk. Confusion, delirium, and intestinal perforation may occur in severe cases, typically after 2–3 weeks of illness. The incubation period for typhoid fever is typically 6–30 days (average 8-14 days).
Compatible symptoms associated with recent travel to an endemic area should trigger suspicion for typhoid fever. However, because of this outbreak, clinicians should also consider typhoid fever in patients with compatible symptoms not explained by recent travel.
Whenever typhoid fever is suspected, multiple sets of aerobic blood cultures should be collected simultaneously and before administration of antimicrobial agents. For adults, two to three 20-mL blood cultures are adequate. Lower volumes may be sufficient for detection in infants and children. Culture of stool, urine, or duodenal contents can also help make the diagnosis. Although not widely used, bone marrow cultures are the most sensitive diagnostic method and can remain positive despite antibiotic therapy. All Salmonella Typhi and Paratyphi isolates should undergo antimicrobial drug susceptibility testing. Serologic tests, such as the Widal test, are not recommended because of the high rate of false positives.
Asymptomatic carriage can occur. Stool specimens should be collected for culture from asymptomatic close contacts of a typhoid fever patient, if the close contact works/attends a high-risk occupation/setting (food service, health care or child care).
Patients suspected of having typhoid fever should be treated with broad spectrum antibiotics. Antimicrobial resistance in typhoid fever has been increasing. Most typhoid and paratyphoid fever infections diagnosed in the United States are caused by strains not susceptible to fluoroquinolones. Therefore, do not use fluoroquinolones for empiric treatment while awaiting susceptibility results. All cases of salmonellosis, including typhoid fever, should be reported to Spokane Regional Health District by calling the 24 hour CD report line (509) 324-1449 or faxing the report to (509) 324-3623.
Additional resources:
Centers for Disease Control and Prevention (CDC). Typhoid Fever and Paratyphoid Fever Information for Healthcare Professionals
