Development and evaluation of a dipstick assay for detection of Plasmodiumfalciparum and P-vivax sporozoites in mosquitoes (Diptera : Culicidae)

We developed a nitrocellulose-based, dipstick circumsporozoite (CS)-enzyme immunoassay [ELISA] for the simultaneous detection of Plasmodium falciparum and P. vivax-210 CS protein. The assay had a detection threshold of <250 P . falciparum or 400 P. vivax sporozoites per sample, gave results concordan t with dissection of salivary glands and CS-ELISA, but was slightly less se nsitive than the CS-ELISA in microtiter plates. The assay consistently dete cted one infected mosquito in a pool of 10 or 20 mosquitoes, and was 100% s pecific in discriminating between species of Plasmodium when mosquito suspe nsions were spiked with sporozoites. The assay could be completed in 1 h, r equired no specialized equipment, and therefore was useful for field applic ations.