| regional perspectives on influenza surveillance in africa. | africa possesses little capacity for influenza surveillance-senegal and south africa being the only countries in the who african region who regularly pursue active surveillance and characterize influenza isolates. south africa has three sites-in cape town, durban and the largest in johannesburg at the national institute for virology (niv). the niv antigenically and molecularly characterizes influenza viruses isolated from specimens provided by a sentinel network of approximately 50 clinical site ... | 2002 | 12110256 |