they represent a big group of mammals. that's why they probably find a lot of viruses in them. there is not a lot of research of how many of those pathogens actually made people sick or animals sick. there is not a direct link between the human outbreaks from the bats. we see some evidence in the bats and we see human outbreaks but we can't say that bat caused the human outbreak. a lot is still unknown, yes. >> a lot still unknown and a lot to keep track of. >> if we look over here, you can see the global disease detection operation center. that shows where we are tracking infectious disease threats. >> that's why having a central command center is critical for this type of work. you will find it at the center for disease control and headquarters in atlanta, georgia. dr. jordan is the director here