1. International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.
2. Institute of Epidemiology, Disease Control and Research, Dhaka, Bangladesh.
3. Centers for Disease Control and Prevention, Atlanta, Georgia.
4. Galveston National Laboratory, Department of Pathology, University of Texas Medical Branch, Galveston, Texas.
5. Department of Biostatistics, University of Washington Seattle, Seattle, Washington.