A 26-year-old woman with no PMH presented to the emergency department (ED) with persistent fever for six days. Patient had dry cough and low grade fevers with one spike to 40oC. After four days of symptoms, patient began azithromycin without relief. One day prior to presentation, patient was discharged from ED for presumed viral syndrome; however, blood cultures were drawn at patient’s insistence. Patient was an ED resident and had recent exposure to sick children. Also, patient had traveled to India three weeks ago where she had two days of diarrhea. Patient was called back to the ED when blood cultures grew gram negative rods in 12 hours. On physical, patient was afebrile, tachycardic to 110bpm, with soft abdomen and no rash. Labs showed mild transaminitis with normal WBC and UA. CXR was clear and abdominal US showed mild hepatomegaly. Blood cultures grew Salmonella paratyphi and patient was treated with two weeks of ceftriaxone. A month later, patient was readmitted with an unusual relapse of the same organism. Patient was given dual therapy of azithromycin and ceftriaxone with successful eradication.
Discussion:
Paratyphoid and typhoid fever have similar syndromes. Symptoms include fever, cough, and abdominal pain starting 1-4 weeks after infection with S. typhi or paratyphi via fecal-oral route. Physical exam findings are pulse-temperature dissociation with relative bradycardia, hepatosplenomegaly, and salmon-colored macules on abdomen (rose spots); none of which our patient had on exam. Lab findings include leukopenia, anemia, and transaminitis. The incidence of typhoid fever in the United States is ~250 cases/year, 80% of whom had travel to endemic regions — south-central Asia, southeast Asia and southern Africa.
Diagnosis is made via blood culture with sensitivity of 60-80%. Stool culture is positive in ~30%, but often negative by fever onset. The most sensitive test is bone marrow culture (up to 95%) and can remain positive for days after starting antibiotics. Prognosis with antibiotics has mortality of less than 1%, but greater than 15% if untreated. First line treatment is ceftriaxone 2g IV daily for 14 days. Other options are azithromycin or ciprofloxacin, though fluoroquinolone resistance is rising. Relapse after ceftriaxone treatment is rare (~5%) and treated with a second antibiotic. There is a vaccine for S. typhi, but it is just partially effective for S. paratyphi.
Conclusions:
Typhoid and paratyphoid fever are very rare in the US and can be easily dismissed as a viral URI given mild symptoms, frequently normal CBC, and long incubation period, which makes travel history easily omitted or overlooked in the HPI. Without treatment, mortality rates exceed 15% from shock or peritonitis. Thus, it is critical to raise awareness to avoid missing the diagnosis and delaying treatment. Further, as our case demonstrated, relapse may occur and appropriate follow up must be set up on discharge from the hospital.