Development and evaluation of a dipstick assay for detection of Plasmodium falciparum and P. vivax sporozoites in mosquitoes (Diptera: Culicidae)

Abstract

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 concordant with dissection of salivary glands and CS-ELISA, but was slightly less sensitive than the CS-ELISA in microtiter plates. The assay consistently detected one infected mosquito in a pool of 10 or 20 mosquitoes, and was 100% specific in discriminating between species of Plasmodium when mosquito suspensions were spiked with sporozoites. The assay could be completed in 1 h, required no specialized equipment, and therefore was useful for field applications.