Stick enzyme-linked immunosorbent assay using the avidin–biotin system for detection of circulating antigen in bancroftian filariasis.

Detection of filarial antigen in different groups of sera was carried out by sandwich as well as inhibition enzyme-linked immunosorbent assays using antibody-coated sticks. Both systems were found to be equally sensitive in detecting antigen in 90% of microfilariae carriers. Incorporation of avidin-biotin in the sandwich assay system increased the sensitivity of antigen detection from 10–6 to 10–16 pg. A 67% decrease in the number of false negative results was observed when the sensitive avidin-biotin inhibition enzymelinked immunosorbent assay system was used for analysis of filaria blood samples.