Mycobacterium ulcerans

CASE 1

• A 35 year old farmer developed an ulcer over the dorsum of his foot several weeks after sustaining a cut in that area from a sharp palm leaf in his field. There is only one ulcer, and it is not painful or tender.

• The patient is afebrile. Examination of the ulcer reveals that a swab can be inserted 5-10mm under the rim through the entire circumference of the ulcer.

• The patient was treated with a combination of streptomycin and rifampin, and the ulcer resolved with formation of a small scar over the next 10 weeks.

Questions:

1. Based on the appearance of the ulcer and the location of the patient’s village, the physician treated the patient for Buruli ulcer disease. How could the diagnosis be confirmed?
2. Why is the ulcer painless?
3. What factor produced by the pathogen is responsible for the tissue destruction and the failure of an adequate local immune response?

CASE 2

• A 22 year old woman from a region known to be endemic for Buruli ulcer disease has painless swelling of one hand for the past 3 weeks.

• The physician obtains a needle aspirate of the affected area and begins therapy for M. ulcerans infection.

Questions:

1. What can be done with the needle aspirate sample to confirm the diagnosis?
2. What would be the expected outcome if the patient were not treated with streptomycin and rifampin for 8 weeks?
3. What other types of lesions are sometimes seen with early infection due to M. ulcerans?