<prompt> How many bacilli should be there in the tissue for slit skin smear to be positive for Hansens disease?10 baccili gram of tissue102 baccili gram of tissue103 baccili i gram of tissue104 baccili gram of tissue  <response>: Ref: Rook s Textbook of DermatologyExplanation:At least 1114 bacilli should be present per gram tissue for 1 bacteriological index in slit skin smear,Maximum number of bacilli in a highly bacillated lepromatous leprosy patient is 1012.Average density of bacilli in lepromatous leprosy is 2.5 billion per 1 cm3 tissue. 