ATTEMPTED TRANSMISSION OF HUMAN GRANULOCYTOTROPIC EHRLICHIA (HGE) BY AMBLYOMMA-AMERICANUM AND AMBLYOMMA-MACULATUM

Transstadial transmission of human granulocytotrophic Ehrlichia (HGE) was attempted in dogs using Amblyomma americanum (L,) and A. maculatum Koch, two species that, as adults, feed readily on human beings. Larv ae and nymphs were acquisition-fed on a dog that was parasitemic with HGE. Two months later, following digestion of the blood meal and subse quent molting to nymphal or adult stage, these ticks were fed to reple tion on HGE-naive dogs. None of the dogs developed clinical evidence o f ehrlichiosis, Parasites were not observed in blood smears by light m icroscopy, HGE DNA was not detected by polymerase chain reaction, and none of the dogs seroconverted. Based on this trial, we conclude that, unlike E. chaffeensis, HGE is probably not transmitted from dog to do g by either A. americanum or A. maculatum.