Hm. Actually, you might be on to something. If the martyr were to explode himself from the inside with grenades, there'd be ebola-carrying gore splattered everywhere. What if he goes to a concert (ehhh... one of those mosh pits or whatever they're called, where they all stand around each other) and blows himself up? It could spark a pandemic. I doubt any first responders would think to check if the guy who blew himself up was infected with ebola, so you could have hundreds of people going about their daily routine for maybe 2-4 days before there's a massive round-up.
ETA: Okay. -So you have two guys go in, at least one infected with ebola. The first guy gets tossed up into the air by the second guy - or maybe only one guy who uses a trampoline - and they try to time it where the guy explodes when he's fairly high up. I'm not sure how far out his parts or blood would go, but I'd guess there'd be a way to get a majority.
Blowing up themselves on a high place like those big lights in football stadiums would do the job. In an indoor arena that could be even more effective. As a minimalist solution climbing to a lamp post clothed as Santa with a big backpack (loaded with "gifts" for the infidels) around Christmas in a busy shopping alley could work as well. I guess for days ppl across the globe would laugh at the stupid lame terrorists whom blown up themselves instead of their victims...