[1] Univ Klinikum Freiburg, Inst Virol, Hermann Herder Strabe 11, D-79104 Freiburg, Germany
[2] WHO, Special Programme Res & Training Trop Dis TDR, Ave Appia 20, CH-1211 Geneva 27, Switzerland
[3] Nasarawa State Univ, Dept Zool, Keffi 911019, Nigeria
[4] Uniklinikum Freiburg, WHO, Inst Mol Diagnost & Infect Dis Control, Keffi 961101, Nigeria
[5] Univ Freiburg, Ctr Med & Soc, Bismarckallee 22, D-79085 Freiburg, Germany