Grading of smears examined in ordinary microscopy at 1000X

magnificationafter ZN staining

----- smear contains no AFB in 100 fields.

NEG

How will you grade a smear with 9 AFB in 100

fields ?

------ Smear with more than 10 AFB per field.

3 +

A smear with 1 to 9 bacilli in majority of the fields will be graded as:

2 +

Smear grade: 2 +(1-9 AFB /field in at

least 50 fields)

Smear Grade: 1 +

10 - 99 AFB in 100 fields

Smear Grade:actual

( < 10 AFB in 100 fields)

Grade the

following smears:

Positive (6AFB)

Positive 1+

1 + (86 AFB/96 HPF)

Positive 2 +

Positive (8 AFB)

Positive 1 +

CreditRevised National Tuberculosis

Control Program-Tuberculosis Research Center

Chennai, India