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Infectious Diseases

Brucellosis

A zoonotic bacterial infection of acute onset, caused by Brucella species. Transmitted via contact with infected livestock (cattle, goats, sheep, pigs, dogs) or contaminated animal products (milk, meat). Incubation 2-4 weeks average.

Also known as: Undulant Fever, Malta Fever, Abortus Fever

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Referral and warning signs

When to refer

Refer suspected cases to HC4/Hospital for diagnosis confirmation (serology/culture) and initiation of appropriate prolonged antibiotic therapy. Refer cases with complications (spondylitis, endocarditis, neurobrucellosis) to specialist/RR.

Red flags

  • Focal neurological signs.
  • Signs of endocarditis (new murmur, heart failure).
  • Severe back pain with neurological symptoms (spondylitis).
  • Failure to respond to initial therapy / Relapse.

Signs and symptoms

  • Intermittent / Undulating / Fluctuating fever (key feature).
  • Generalized aches and pains (arthralgia, myalgia).
  • Headache, fatigue, weakness.
  • Sweating (often profuse, night sweats).
  • Loss of appetite, weight loss.
  • Hepatosplenomegaly.
  • Lymphadenopathy.
  • Orchitis (inflammation of testes).
  • Sacroiliitis / Spondylitis (vertebral osteomyelitis) - uncommon but characteristic.
  • Neurobrucellosis (meningitis, encephalitis - rare).
  • Endocarditis (rare).

Risk factors

  • Occupational exposure (farmers, veterinarians, abattoir workers, butchers, lab workers).
  • Consumption of unpasteurized milk or dairy products.
  • Consumption of undercooked contaminated meat (e.g., 'muchomo').
  • Direct contact with infected animals or their secretions/tissues.

Diagnosis

Clinical assessment

Suspicion based on prolonged/undulant fever, arthralgia/myalgia, fatigue, sweats, and relevant exposure history (occupation, animal contact, food consumption).

Differential diagnosis

  • Typhoid fever
  • Malaria
  • Tuberculosis (TB)
  • Trypanosomiasis (Sleeping Sickness)
  • Infective endocarditis
  • Lymphoma
  • Other causes of prolonged fever (PUO)

Investigations

  • Serology: Agglutination tests (e.g., SAT - Standard Agglutination Test, Rose Bengal) or Complement Fixation Test (CFT) or ELISA. Interpretation challenging in endemic areas due to background positivity; titres >1:160 or rising titres more significant. Positive results can persist after recovery.
  • Blood Culture: Definitive diagnosis if positive, but often low yield and requires prolonged incubation/special media.
  • Bone Marrow Culture: Higher yield than blood culture.
  • Culture from other tissues (lymph node, CSF, joint fluid) if involved.

Diagnostic criteria

Clinical suspicion + Supporting serology (interpret with caution) OR Definitive diagnosis by culture.

Management

Non-pharmacological management

  • Supportive care (rest, analgesia).

Pharmacological treatment

  • Requires prolonged combination antibiotic therapy (6 weeks minimum) to prevent relapse. (LOC: HC4)
  • Preferred Regimen (Adult & Child >8 years):
  • - Doxycycline 100 mg PO every 12 hours for 6 WEEKS
  • (Child >8y: 2 mg/kg/dose BID)
  • - PLUS Gentamicin 5-7 mg/kg IV/IM daily for 2 WEEKS
  • (Child >8y: Dose as per adult)
  • Alternative Parenteral agent (if Gentamicin unavailable/contraindicated):
  • - Streptomycin 1g IM daily for 2-3 weeks (Specialist use, ototoxicity/nephrotoxicity monitoring needed)
  • Regimen for Children <8 years:
  • - Cotrimoxazole 24 mg/kg PO every 12 hours for 6 WEEKS
  • - PLUS Gentamicin 5-7 mg/kg IV/IM daily (in 1-3 divided doses) for 2 WEEKS
  • Alternative Regimen (e.g., if Doxy/Gentamicin C/I - specialist advice):
  • - Doxycycline 100mg BID + Rifampicin 600-900mg daily for 6 weeks.
  • - Cotrimoxazole + Rifampicin for 6 weeks.
  • Note: Ciprofloxacin mentioned in UCG as alternative to Gentamicin BUT generally less preferred due to resistance/relapse risk, and contraindicated <12 years. Doxycycline/Gentamicin contraindicated in pregnancy.

Monitoring

Monitor clinical response. Adherence to full 6-week course is crucial. Monitor for relapse after treatment completion.

Complications

  • Relapse (common if treatment inadequate/short).
  • Osteoarticular complications (arthritis, sacroiliitis, spondylitis).
  • Orchitis/Epididymitis.
  • Neurobrucellosis.
  • Endocarditis.
  • Hepatic abscess.

Prevention

  • Pasteurization of milk and dairy products.
  • Thorough cooking of meat.
  • Occupational safety (use of PPE - gloves, masks, eye protection) for those handling animals/carcasses.
  • Vaccination of livestock.
  • Careful handling of potentially infected animal tissues/secretions.

Patient education

  • Explanation of the zoonotic source.
  • Critical importance of completing the FULL 6-WEEK antibiotic course to prevent relapse.
  • Potential side effects of medication.
  • Prevention measures (pasteurized milk, cooked meat, occupational safety).
  • Need for follow-up.

Uganda-specific notes

Present in Uganda, linked to livestock. Diagnosis challenging due to nonspecific symptoms and limitations of serology interpretation. Prolonged treatment essential. Doxycycline + Gentamicin often used.

References

  • Uganda Clinical Guidelines (UCG) 2023

    Chapter 2, Section 2.1.2

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