Host antibodies in mosquito bloodmeals: a potential tool to detect and monitor infectious diseases in wildlife.

When a female mosquito bites, it carries away a blood sample containing specific antibodies that can provide a history of the immune responses of its vertebrate host. This research examines the limits and reliability of a technique to detect antibodies in blood-fed mosquitoes in the laboratory. Mosquitoes were fed on blood containing a specific antibody, and then they were assayed using an enzyme-linked immunosorbent assay to determine the limits of detection of antibody over time, at different temperatures and initial antibody concentrations. The antibody, at an initial concentration of 1 microg/ml, could be detected in mosquitoes for 24-48 h after feeding. Blind tests simulating the assay of feral mosquitoes were used to test the reliability of the method and detected positive mosquitoes with few false negatives and no false positives. Specific antibodies also could be detected in mosquitoes that had been air-dried or preserved in ethanol. This research indicates that, in theory, the collection and immunological assay of blood-fed mosquitoes could be developed to detect and monitor infectious disease in wildlife.