Brucellosis is one of the world's most common zoonoses, particularly in poor rural settings. Most cases in northern Europe and North America are acquired overseas and/or from consuming unpasteurized milk or milk products.
Rarely fatal, but relapse can occur with debilitating and economically devastating effects. It is considered a bioterrorism agent, is easily spread by aerosol, and is a significant hazard in microbiology laboratories.
Can affect any organ system and therefore presents in a variety of ways, especially as a prolonged fever of unknown origin, with associated rheumatic features.
Combination antibiotic therapy is the mainstay of treatment and should be used for prolonged periods to prevent relapse of symptoms. There is disagreement about the optimum treatment regimen.
A zoonotic disease that can affect various organs, tissues, and systems. In humans it is caused by Brucella species including B melitensis, B abortus, B suis, and B canis (and more rarely by B pinnipediae, B cetaceae, and B inopinata BO1), which are pleomorphic gram-negative bacteria transmitted to humans from animal reservoirs. The disease tends to relapse and can rarely become chronic, although the definition and classification of chronic brucellosis remains controversial.Brucella species are considered class B bioterrorism agents, due to the ease of infection through the inhalation of organisms.
History and exam
Key diagnostic factors
- history of contact with infected person
- fever or chills
- constitutional symptoms
- joint swelling and tenderness
- hepatomegaly and/or splenomegaly
Other diagnostic factors
- nausea, vomiting, abdominal pain, constipation, diarrhea
- dry cough
- chest signs
- testicular pain
- neck stiffness
- cranial nerve palsy or focal central nervous system deficit
- dullness to percussion, decreased air entry, crepitations
- red eye
- skin rashes
- ingestion of contaminated foods
- exposure to infected animal products
- inhalation of infected aerosols
- conjunctival contact with infected material
- occupation with potential for exposure to Brucella species
- travel to an endemic area
- cuts or abrasions in skin
- sexual contact with infected individual
- newborn or infant of infected mother
- recipient of blood products or of organ or tissue transplant
1st investigations to order
- blood culture
- serologic tests
- cerebrospinal fluid (CSF) analysis
- cerebrospinal fluid (CSF) culture
- synovial fluid analysis
- synovial fluid culture
- liver function tests
Investigations to consider
- bone marrow culture
- tissue biopsy
- plain film x-rays of affected joints
- chest x-ray
- bone scan
- CT or MRI scan of spine
- CT or MRI scan of head
- polymerase chain reaction for detection and diagnosis of Brucella species
- matrix-assisted laser desorption/ionization time of fligh (MALDI-TOF) mass spectrometry
Nicholas J. Beeching, MA, BM BCh, FRCP, FRACP, FFTM RCPS (Glasg), FESCMID, DCH, DTM&H
Consultant and Emeritus Professor of Tropical and Infectious Diseases
Royal Liverpool University Hospital
Liverpool School of Tropical Medicine
NJB is partially supported by the National Institute of Health Research Health Protection Unit in Emerging and Zoonotic Infections at the University of Liverpool and Public Health England. Views expressed in this topic are those of the contributor and do not necessarily represent the official position of the National Health Service, the National Institute for Health Research, the Department of Health, or Public Health England. NJB is an author of references cited in this topic.
Alessandro Gerada, MD, MRCP, FRCPath
Consultant in Clinical Microbiology
Liverpool Clinical Laboratories
Royal Liverpool University Hospital
AG is an author of several references cited in this topic.
Sherine Thomas, MBChB, MRCP, DTMH
Consultant in Infectious Diseases
Whipps Cross Hospital
ST declares that she has no competing interests.
Mical Paul, MD
Infectious Diseases Consultant
Unit of Infectious Diseases
Rabin Medical Center
MP declares that she has no competing interests.
Edward J. Young, MD
Professor of Medicine
Section of Infectious Diseases
Department of Medicine
Baylor College of Medicine
EJY declares that he has no competing interests.
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