lab workers as roy, we'll, if this was something that was escaping from a lab. presumably, some of the lab rutgers one in the first infected. what we've heard was that blood was drawn from those lab workers but we haven't seen the results. of what those tests showed. and then we'd also like to have forensic investigation to try to find out what you don't even know to look for. you want teams in there to investigate the lab. those are the sorts of things you want to do. but these are the things when they say there hasn't been transparency, it's a sort of information that hasn't been forthcoming. >> the world health organization, wha, sanjay, has been waiting for the next phase of the investigation. but you've spoken with experts who have worked in wuhan. what do they say to you about how hard it is