Institution: | Author affiliations: Ministry of Health, Cairo, Egypt (A. Kandeel, E. Abdul Kereem, S. El-Refay, M. Abukela, N. El-Sayed, H. El-Gabaly);;Centers for Disease Control and Prevention, Atlanta, Georgia, USA (M. Deming);;US Naval Medical Research Unit No. 3, Cairo, Egypt (S. Afifi, K. Earhart) |