In the warm seasons it lies waiting for a meal of fresh blood. Then it inserts its hypostome, a swordlike probe with row upon row of microscopic teeth, and begins to suck. Hours to days later, fully engorged and sometimes 100 times heavier, the tick falls off. In the meantime, there has been a small transfer of fluid from the tick to the victim. If the tick is infected with a pathogen like E. chaffeensis , it can transmit the infection in that fluid.
Some researchers suspect most are.
If the disease is recognized and treated with tetracycline, it's easily cured. But if it's missed and infection progresses without treatment, patients can die from causes ranging from brain infection to respiratory problems. Nearly a year has passed since Mr. Ervin encountered that tick in the woods of southern Indiana. It is now, once again, full summer here, but this time we know the beast. The case described in Vital Signs is based on a true story.