[Undulant fever and autoimmune hemolytic anemia in a 20-year-old exchange student from Jordan - the human brucellosis as an important differential diagnosis in migrants].

HISTORY AND CLINICAL FINDINGS: A 20-year-old Jordanian exchange student presents with recurrent fever, night sweats, cough, and swelling and redness around the ankle. Physical examination further reveals bilateral ankle arthritis and painful cervical lymphadenopathy.

INVESTIGATIONS AND DIAGNOSIS: Laboratory tests show signs of autoimmune hemolytic anemia, elevated liver function tests, and moderate laboratory signs of inflammation. All blood cultures reveal growth of gram-negative coccoid rods which are initially identified by mass spectrometry as Moraxella lacunata and Ochrobactrum anthropi. However, antimicrobial therapy with imipenem / cilastatin does not improve the patient's clinical condition. Based on the travel history including consumption of yogurt from unpasteurized sheep's milk, we perform serological tests with a strongly positive result for Brucella species, and additional work-up of blood culture isolates confirm the definitive diagnosis of brucellosis (Malta fever, infection by Brucella melitensis).

TREATMENT AND COURSE: After initiation of antimicrobial therapy with doxycycline and rifampin the patient shows complete resolution of fever. Arthritis, autoimmune hemolytic anemia and accompanying hepatitis improve in the course.

CONCLUSIONS

Thus, since brucellosis is endemic to countries like Jordan, it should be considered as a possible agent of fever of unknown origin especially in migrants unresponsive to empiric therapy and appropriate diagnostic tests including meticulous validation of blood cultures should be performed. Standard therapy is a combination of doxycycline with rifampin for at least 6 weeks.