Buruli Ulcer Flashcards
What causes Buruli Ulcer ?
Mycobacterium ulcerans
Occurs in :
- people living close to lakes, rivers, or marshy areas
- mining, deforestation or flooding
- Trauma- most likely means by which Mycobacterium ulcerans is introduced
- Hypothesis: Inoculation of Mycobacterium ulcerans into the skin -by aquatic insects or -by mosquitoes (Australian scientists) So basically nobody fucking knows.
Disease geographical distribuion?
SSA West > east and Australia (just a few coastal locations
Disease epidemiology?
In Africa overwhelmingly affects children. In Australia, adults
Pathogenesis
The ulcer is caused by M Ulcerans secreting a toxin called MYCOLACTONE
It causes:
- Cell cycle arrest
- Apoptosis
- At low concentration it suppresses – Dendritic cells – Macrophage – T-cell function abrogating cytokine and chemokine secretion in response to mitogens • Down regulation of: – Inflammatory mediators – Lipid metabolism – Coagulation – Tissue remodeling
Clinical presentation
Active disease is divided into: • non-ulcerative (papule, nodule, plaque, oedema) • ulcerative forms and osteomyelitis
Differential for non ulcerative buruli
- Abscess—————————Painful
- Lipoma———————– Mobile
- Ganglion————————-Close to joints
- Tuberculous lymphadenitis—-Constitutional symptoms
- Onchocerciasis nodule———-Painless, longhistory
- Subcutaneous infections such as fungal infection
Differential Diagnosis for ulcer
- Tropical phagedenic ulcers
- Arterial and venous insufficiency • Diabetic ulcers
- Sickle cell ulcer
- Cutaneous leishmaniasis
- Extensive ulcerative yaws
- Haemophilus ducreyi ulcers
Diagnosis of Buruli
- Swabs for ulcerative lesions
- Fine needle aspiration (FNA) for mainly
non-ulcerative lesions
– nodules,
– papules
– oedema
– some ulcerative lesions
Goal is PCR. Highly sensitive and specific.
• Biopsy in case of surgery
Management
Principles of current BU management
• Antibiotic appropriate to kill organisms • Enhance wound healing
Nutrition Wound care Skin grafting
• Disability prevention (simple exercises) • Rehabilitation
RIFAMPICIN + CLARITHROMYCIN
Or Streptomycin (never in pregnant women) or Moxifloxacin
Antibiotic side effects
Antibiotic side effects
In less than 2% of patients
skin rash (streptomycin & rifampicin)
deafness, dizziness, vomiting, decreased urine output (streptomycin),
anorexia, nausea, abdominal pain, jaundice and renal failure (rifampicin)
Nausea, altered taste, jaundice, hepatitis (clarithromycin)
Tendonitis, rash (moxifloxacin)
Describe Paradoxical reactions and their management
Paradoxical reactions
Occurred in 8.4% of patients
Lesion enlargement, pus filled, same/new site
May be culture positive during antibiotic treatment
Associated with high bacterial load
Heal without antibiotic treatment beyond 8 weeks and with & without corticosteroids
Unpredictable
Describe the WHO Buruli ulcer Control Strategy
Early case detection (education at village level)
Improved care (labs, treatment, wound care etc)
Supporting activities (Supervision advocacy and research)
all leading to: health system improvement
