1. MRC/SAIMR/WITS Pneumococcal Diseases Research Unit, Johannesburg, South Africa1;
2. Nosocomial Pathogens Laboratory Branch, Centers for Disease Control and Prevention, Atlanta, Georgia 303332;
3. Department of Infectious Disease Epidemiology, Imperial College School of Medicine,3 and
4. Respiratory and Systemic Infection Laboratory,4 London, England;
5. University of Kaiserslautern, Kaiserslautern, Germany5;
6. Sera and Vaccines Central Research Laboratory, Warsaw, Poland6;
7. Laboratoire de Bactériologie, Toulouse, France7; and
8. Rockefeller University, New York, New York 100218