1. Division
of Healthcare Quality Promotion, Centers for Disease Control and
Prevention, Atlanta, Georgia 30333
2. Department of Medical Microbiology,
Creighton University, Omaha, Nebraska 68178
3. Genomics—Cambridge,
Wyeth Research, Cambridge, Massachusetts
02140
4. Department of Pathology and
Microbiology, University of Nebraska Medical Center, Omaha,
Nebraska
68198