<prompt> Patient with leprosy, smear sample taken show 10- 100 bacilli in one field. Bacterial index is:1234  <response>: Bacterial index is calculated by counting the number of bacilli in 100 fields under oil immersion Grade Number of bacilli 1 1 to 10 bacilli per 100 fields 2 1 to 10 bacilli per 10 fields 3 1 to 10 bacilli per field 4 10 to 100 bacilli per field 5 100 to 1000 bacilli per field 6 Multiple clumps of bacilli present 