Closing the Brief Case: Salmonella enterica Serovar Typhi in a Central American Refugee

• S. Typhi should be considered in the differential of patients presenting with abdominal complaints and with a travel history to endemic regions, such as Central and South America, Africa, the Middle East, and Southeast Asia.

• Patients presenting with S. Typhi may be afebrile at initial presentation, with a normal total white blood cell count.

• S. Typhi is an oxidase-negative, indole-negative lactose nonfermenter. This organism will grow as green colonies with slight or absent H₂S production on Hektoen enteric agar. Serological testing of the isolate will be positive for serogroup D and Vi antigen.

• S. Typhi is showing increasing resistance to fluoroquinolones, and susceptibility testing to ciprofloxacin using updated interpretive breakpoints is necessary to guide therapy. Initial antimicrobial susceptibility testing for S. Typhi isolates should include ampicillin, trimethoprim-sulfamethoxazole, and a third-generation cephalosporin, in addition to a fluoroquinolone (generally ciprofloxacin).

• Blood cultures and bone marrow cultures are the most sensitive methods for recovering S. Typhi. Other potential specimens for culture include rose spots, stool, and cerebrospinal fluid (children).

Click here to read the article, published in Journal of Clinical Microbiology.