If I remember correctly, it isn't exactly widespread in its effect, the staff. As for the virus, it has a possibility of being a contender, but the Flood is likely much greater. Once a Jedi or a Yuuzhan Vong gets infected, the war is pretty much over. Once the Flood gets to work with the Vong, it will get entire worlds of organic matter to assimilate. With any force-user, the Flood will gain the knowledge of the Force and the ability to use it.