Double-antibody sandwich and modified sandwich systems of enzyme-linked immunosorbent assay for detecting chikungunya virus antigen present in female mosquitoes, Aedes albopictus (Oahu strain), were evaluated as simple and rapid methods of selection of a highly susceptible mosquito line. Both assays were capable of detecting 3.9 X 10(1) ng (4.0 X 10(6) PFU) or more of the purified antigen. An inhibition system was less sensitive, and a direct system with adsorption of test specimens on the solid phase was not useful. Positive reactions were observed in 16 (48.5%) of 33 infected mosquitoes with with 10(6) to 10(7) PFU, which correspond to the highly susceptible group of this strain. Mosquitoes with less than 10(6) PFU were all negative, indicating the usefulness of the sandwich techniques for identifying high-titered mosquitoes.