Molecular Virology and Bioinformatics, Africa Centre/University of Natal, Durban, South Africa. toliveira@mrc.ac.za|Molecular Virology and Bioinformatics, Africa Centre/University of Natal, Durban, South Africa. toliveira@mrc.ac.za|Molecular Virology and Bioinformatics, Africa Centre/University of Natal, Durban, South Africa. toliveira@mrc.ac.za|Molecular Virology and Bioinformatics, Africa Centre/University of Natal, Durban, South Africa. toliveira@mrc.ac.za