Brucella...ella...ella...eh

Today we discussed a case of a middle-aged woman recently coming from Mexico who presented with a month of fevers, found to have brucellosis. A few learning points:

1) Exposure history to get:

  • The most common way to be infected with Brucella is through the ingestion of contaminated milk products.  Thus, a particular risk to tourists are "village cheeses" or unpasteurized cheeses from the Mediterranean basin (hence the term Malta fever), Eastern Europe, South America, the Middle East, Africa and the Caribbean.
  • Brucella can also be contracted thorough inhalation (slaughterhouse workers, lab workers) or skin wounds with contact of infected animals (cattle, sheep, goats, pigs, other animals). 

2) Initial clinical presentation:  acute or insidious onset of fever and one or more of the following: night sweats (characteristically with a particularly foul, moldy smell ), arthralgia, headache, fatigue, anorexia, myalgia, weight loss, arthritis/spondylitis, meningitis, or focal organ involvement (endocarditis, orchitis/epididymitis, hepatomegaly, splenomegaly).

However, clinical presentations can vary significantly given that Brucella can affect any organ system, but about 70% of cases have GI involvement (anorexia, abdominal pain, vomiting, diarrhea, constipation, hepatomegaly, hepatitis, hepatic abscesses, and splenomegaly).

3) Diagnosis, according to the CDC, here. Some helpful clinical specimens to collect: blood or wound culture (although Brucella is a fastidious organism and can take over a week to grow), Brucella antibody titer (although this can be difficult to interpret in chronic infection or relapse/reinfection if living in an endemic area), and Brucella DNA PCR.  Interestingly, bone marrow culture is the gold standard.

4) Treatment:

  • Uncomplicated (no foci of infection): doxycycline 6 weeks + aminoglycoside or rifampin for 2-6 weeks
  • Complicated: at least 12 weeks of above for spondylitis, endocarditis, abscesses, CNS involvement