1. California Emerging Infections Program, San Francisco, California, USA; †California Department of Health Services, Berkeley, California, USA; ‡University of California, San Francisco, California, USA; §School of Public Health, University of California, Berkeley, California, USA; ¶San Francisco Department of Public Health, San Francisco, California, USA; #Centers for Disease Control and Prevention, Atlanta, Georgia, USA; and **IntraBiotics Pharmaceuticals, Mountain View, California, USA