Kinetic development and decline of antiscrewworm (Diptera: Calliphoridae) antibodies in serum of infested sheep.

Sheep infested with screwworms, Cochliomyia hominivorax (Coquerel), produced specific serum antibodies detectable by ELISA. Significant antibody levels were found beginning at 1 wk after infestation and persisting for 2 mo, with peak levels at 3 wk after infestation. Mean response values and corresponding larval survivorship were similar over a range of 25 to 200 larvae per individual sheep. Anomalous seropositive responses in some noninfested sheep suggested the possibility of cross-reactivity between antigens of screwworm and those of related myiasigenic blowflies.