1. Abbott Diagnostics, Abbott Park, Illinois 60064.
2. Université de Yaoundé, Yaoundé, Cameroon.
3. MRC/UVRI Uganda Research Unit on AIDS, Entebbe, Uganda.
4. Université des Montagnes, Bangangté, Cameroon.
5. Goethe University, Frankfurt, Germany.
6. University of Missouri-Kansas City, Kansas City, Missouri 64110.