Finger-prick blood collection and computer-assisted enzyme-linked immunosorbent assay for large-scale serological studies on leprosy.

An immunoglobulin M anti-phenolic glycolipid 1 assay was standardized and optimized using specimens of dried blood collected on commercial precut filter paper discs, followed by a computer-assisted enzyme-linked immunosorbent assay (ELISA). The correlation between venepuncture and finger-prick methods, the calibration of the quantity of absorbed blood, and the reproducibility of the ELISA test were excellent. A slight decline of activity was observed when the samples were stored for 3 months at +4 degrees C. Skimmed milk can be used as diluent instead of bovine serum albumin, contributing to lessening the cost of the test. Using the method described, as many as 300 samples can be collected in the field and 480 ELISAs per day can be run in the central laboratory by one trained person.