Use of Whatman chromatography paper for serological studies in leprosy in the field

Recently W.H.O. recommended further serological studies on leprosy using samples collected on filter paper strips. A study was therefore taken up at C.L.T. and R.I., Chengalpattu, to find out the relative efficiency of the serological tests conducted on sera and filter paper eluates. FLA-ABS and FA-BCG tests were carried out on 100 paired samples. With the former, exactly the same titres were obtained in 42% and with the latter in 52% cases. Most of the others showed positivity at one-dilution-low titres. In 6-8% cases only, the filter paper technique showed negativity. The correlation co-efficient was +0.87 with FLA-ABS and +0.85 with FA-BCG test. The filter paper technique was operationally more convenient and was acceptable without substantially loosing the efficacy.