A 36-year-old man returning from India with suspected typhoid fever; what is the most critical laboratory test to establish or rule out the diagnosis?

A 36-year-old man returning from India with suspected typhoid fever; what is the most critical laboratory test to establish or rule out the diagnosis?

• A. Blood cultures
• B. Sputum cultures
• C. Stool cultures
• D. Urine cultures

Answer: (A)

Typhoid fever is a systemic infection where Salmonella Typhi circulates in the blood during the febrile phase. Because the pathogen is in the bloodstream early on, blood cultures provide the clearest, most direct evidence of infection and allow definitive identification and antibiotic susceptibility testing to guide treatment. Stool cultures can become positive later as the bacteria are shed in the GI tract, but they are less reliable for early diagnosis. Sputum and urine cultures are not routinely indicative of typhoid in most patients. Therefore, obtaining blood cultures offers the highest diagnostic yield to establish or exclude the diagnosis in a returning traveler with suspected typhoid fever.

Typhoid fever is a systemic infection where Salmonella Typhi circulates in the blood during the febrile phase. Because the pathogen is in the bloodstream early on, blood cultures provide the clearest, most direct evidence of infection and allow definitive identification and antibiotic susceptibility testing to guide treatment. Stool cultures can become positive later as the bacteria are shed in the GI tract, but they are less reliable for early diagnosis. Sputum and urine cultures are not routinely indicative of typhoid in most patients. Therefore, obtaining blood cultures offers the highest diagnostic yield to establish or exclude the diagnosis in a returning traveler with suspected typhoid fever.