1. Unité d'Epidémiologie et Physiopathologie des Virus Oncogènes, Département d'Ecosystème et Epidémiologie des Maladies Infectieuses, Batiment Lwoff, Institut Pasteur, 25–28 rue du Dr Roux, 75724 Paris Cedex 15, France
2. HIV and Retrovirology Branch, Division of AIDS, STD, and TB Laboratory Research, National Center for Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd, MS G-19, Atlanta, GA 30333, USA
3. Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Disease, National Institutes of Health, Rockville, MD 20852, USA
4. Cercopan, Calabar, CRS, Nigeria