Comparative value of Dapsone "spot test" and Dapsone "tile test" in leprosy control programme.

Area of Science:

• Pharmacology and Therapeutics
• Clinical Chemistry
• Public Health

Background:

• Accurate monitoring of dapsone adherence is crucial for effective leprosy treatment.
• Existing methods for assessing drug consumption can be resource-intensive.
• Qualitative field tests offer a potential alternative for widespread screening.

Purpose of the Study:

• To compare the diagnostic accuracy of two qualitative dapsone urine screening tests (spot test and tile test) against a quantitative method (Dapsone/creatinine ratio).
• To evaluate the concordance of results obtained by field-based paramedical workers and laboratory personnel.
• To assess the feasibility of implementing these tests for large-scale monitoring of leprosy patients.

Main Methods:

• 316 urine samples were analyzed using the Dapsone 'spot test' and 'tile test' in the field and laboratory.
• Samples were also subjected to quantitative Dapsone/creatinine ratio analysis in the laboratory.
• Results from qualitative tests were compared with the quantitative test and between different personnel.

Main Results:

• The qualitative spot and tile tests demonstrated a 91% correlation with the quantitative Dapsone/creatinine ratio.
• High concordance (97%) was observed between results from paramedical workers and laboratory technicians.
• Previous studies indicate such monitoring can reduce irregular drug consumption from 36% to 17%.

Conclusions:

• The dapsone spot and tile tests are reliable, simple, and portable qualitative methods for screening dapsone in urine.
• These tests can be effectively performed by paramedical workers in field settings, showing high agreement with laboratory results.
• Routine, frequent, and surprise urine testing using these field-deployable kits is recommended for mass-scale monitoring of dapsone adherence in leprosy patients.