1. National Public Health Laboratory, Libreville, Gabon;
2. Catholic University of Central Africa, 84881, Yaounde, Cameroon
3. NationalPublic Health Laboratory, Libreville, Gabon;
4. National Center for Blood Transfusion, 149930, Libreville, Gabon;
5. Catholic University of Central Africa, 84881, Yaounde, Cameroon;
6. Chantal Biya International Reference Centre for HIV/AIDS Research on Prevention and Treatment, 151785, Yaounde, Cameroon;