Persister M. leprae after introductory rifampicin followed by dapsone therapy

Area of Science:

• Microbiology
• Infectious Diseases
• Dermatology

Background:

• Leprosy, a chronic infectious disease, requires long-term treatment.
• Rifampicin and Dapsone (DDS) are key components of multidrug therapy for leprosy.
• Identifying persistent infections is crucial for effective disease control.

Purpose of the Study:

• To investigate the presence of persistent Mycobacterium leprae in the skin of lepromatous leprosy patients after a specific treatment regimen.
• To evaluate the efficacy of an introductory Rifampicin therapy followed by Dapsone maintenance therapy in eliminating M. leprae.

Main Methods:

• The study involved lepromatous leprosy patients receiving 300 mg Rifampicin daily for 3 months, followed by 50-100 mg Dapsone (DDS) daily for 21 months.
• Skin biopsies were analyzed for the presence of viable Mycobacterium leprae using the mouse foot pad model at the end of the 2-year treatment period.

Main Results:

• Viable Mycobacterium leprae were detected in the skin of 3 out of 6 patients investigated.
• These persistent M. leprae were identified at the conclusion of the 2-year treatment course.

Conclusions:

• The investigated treatment regimen, while extensive, did not completely eradicate Mycobacterium leprae in all lepromatous leprosy patients.
• The findings highlight the challenge of eliminating persistent M. leprae and suggest the need for further research into treatment strategies.