McDonald Marian, Anker Martha, Deal Carolyn, Mawle Alison, O'Connor Siobhán, Slaughter Larisa
Centers for Disease Control and Prevention, Atlanta, Georgia, USA;
World Health Organization, Geneva, Switzerland;
Emerg Infect Dis. 2004 Nov;10(11):1963-2036. doi: 10.3201/eid1011.040612.