This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
Most sensitive index of transmission in leprosy is? 
Select and explain. 
A. Incidence, B. Detection rate, C. Disability rate, D. Prevalence
A: Incidence
Answer: A: Incidence 
Explanation: Ans. is 'a' i.e., Incidence Incidence rate It is the only index for measuring the effectiveness of the measures taken. It is the most sensitive index of transmission of the disease. Prevalence It provides a measure of the 'case-load'. It is useful in the planning of treatment services. The efficacy of the drug regimen is best indicated by relapse rate.