IDENTIFICATION OF BLOOD MEALS IN AEDES-AEGYPTI BY ANTIBODY SANDWICH ENZYME-LINKED-IMMUNOSORBENT-ASSAY

A comparative study of 3 ELISA protocols was performed for host blood meal identification in Aedes aegypti. In the sandwich-B ELISA, which u sed a combination of heavy and heavy + light chain conjugates, specifi city was improved to such a degree that conjugates no longer required cross-adsorption with heterologous sera. Using the sandwich-B assay, h uman blood meals in laboratory reared Ae. aegypti could be detected lo nger after feeding (100% at 32 h and 80% at 42 h) than with a direct a ssay (100% at 20 h). Efficacy of the sandwich-B and direct ELISAs in f ield analyses was studied in parallel using 80 field collected mosquit oes from Thailand. The sandwich-B assay was superior (88% detection ra te) to the direct assay (41% detection rate) and was thus selected as the method of choice for future field studies.