Brucellosis

Brucellosis is a zoonotic infection caused by gram-negative bacilli

• B.melitensis– goats, sheep, and camels. Causes most severe disease
• B.abortus– cattle
• B.suis– pigs. Causes abscesses.
• B.canis– dogs

Infection to humans- ingestion of contaminated dairy products, uncooked meat, or offal. Also, direct contact with irritated skin or aerosols to the respiratory tract. Incubation 2- 4 weeks.

Clinical features

• The disease is chronic and tends to relapse- survive for long in the reticuloendothelial system.
• Insidious onset of high swinging fevers, malaise, night sweats, arthralgias, scrotal pain, weight loss, headache, and abdominal pain
• Examination- lymphadenopathy, hepatomegaly, splenomegaly

Complications – due to focal disease

• Osteoarticular disease
• Orchitis, epididymitis
• Spontaneous abortion, fetal demise, premature delivery
• Meningitis, encephalitis, endocarditis
• Abdominal abscess, uveitis

Diagnosis

• Definitive- a culture of blood, CSF, and bone marrow
• Serology- high titer of antibodies or four-fold rise- shows acute infection
• Liver function tests- raised transaminases
• Complete blood count- anemia, lymphocytosis, thrombocytopenia

Management

• Depends on the area with localized disease
• Aminoglycosides+ tetracyclines- synergistic

1. Nonlocalised disease- doxycycline+gentamicin/rifampicin
2. Bone disease- doxycycline+gentamicin+rifampicin
3. Neurobrucellosis- Doxycycline+rifampicin+ceftriaxone
4. Endocarditis- doxycycline+rifampicin+cotrimoxazole +surgery
5. Pregnancy- rifampicin+ cotrimoxazole

Differential diagnosis

• Tuberculosis
• Malaria
• Visceral leishmaniasis
• HIV infection
• Endocarditis
• Sarcoidosis
• Malignancy