Brucellosis

Brucellosis is a zoonosis more common in the Middle East and in farmers, vets and abattoir workers. Four major species cause infection in humans: B. melitensis (sheep), B. abortus (cattle), B. canis and B. suis (pigs). Brucellosis has an incubation period of 2–6 weeks. Transmission may occur through direct contact with infected animals or consumption of unpasteurised dairy products. It is a notifiable disease in the UK.

• non-specific: fever (often undulant), malaise, night sweats, fatigue
• hepatosplenomegaly
• musculoskeletal: arthralgia, sacroiliitis, spondylodiscitis (spinal tenderness may be seen)
• complications: osteomyelitis, infective endocarditis, meningoencephalitis, orchitis
• leukopenia and anaemia may be seen

• the Rose Bengal plate test is a rapid screening tool but not diagnostic
• Brucella serology (e.g. standard agglutination test) is the mainstay of diagnosis
• blood and bone marrow cultures may be suitable in certain patients, with bone marrow having higher diagnostic yield, particularly in chronic disease

• first-line: doxycycline (6 weeks) + rifampicin (6 weeks)
• alternative: doxycycline (6 weeks) + streptomycin (for first 2–3 weeks) in cases where rifampicin is unsuitable
• prolonged or triple therapy (e.g. with gentamicin) may be required for complicated or focal disease such as spondylitis or endocarditis