Parasitology. Close encounters: good, bad, and ugly.

Microbiologists often focus on one organism and its relationship to its host at one point in time. But viewed in light of evolution, host-parasite relationships range from deadly to helpful, depending on the communication between them. At a meeting here last month of virologists, bacteriologists, parasitologists, and molecular biologists--each dealing with different microorganisms in distinct ways--researchers lamented that evolution is often considered outside the bailiwick of microbiologists, particularly those studying infectious diseases.