Ending?????

i didn't think the plot twist was terrible. i didn't see it as much of a plot twist actually sense samwise very obviously was intent on infecting people and didn't give a damn about anyone.

The mouse did not infect patient zero. The virus was already in his blood, but because of his "immunity" (I'm not sure if this is the correct medical term for his condition. He seems more like a passive carrier. But I'm no doctor.) he can't get sick. The mouse was perfectly fine, he used it as a carrier for his infected blood.

The mouse is shown near a cup of coffee and near the coffe machine itself, so I assume it somehow got patient zero's blood into the coffee. Afterwards the team members infected each other by vomiting etc.

I don't recall any part of the movie showing that the virus spreads by touch alone. But it spreads by getting in contact with infected water or the blood/ other bodily fluids of an infected person.

However it has been several months since I watched the movie and it was not very memorable.

Like DaVinci said, it's still spread by contact with infected fluids or mucous membranes, kinda like Ebola. The first route of contact for all 3 movies seems to be via contaminated water (that's been contaminated basically by someone bleeding out in a communal source, and then it being ingested or coming in contact with it via mucous membrane (eyes, nose, mouth for the snorkelers). In Patient Zero, we see the bitchy lab girl get kinda startled and drop the mouse, and then, for whatever reason, she never even makes an attempt to pick it up. Magically, though Porter is quarantined, the mouse gains entrance to the quarantine, and he's able to squeeze his virusy blood all over it, and it scurries out during all the scurfuffle, then making it magically all the way through the stampede of people trying to get out into the safe bunker, and it then manages to rub its virusy blood soaked body all over food, glassware, and silverware, which some people used & got infected. Those that did not use mouse infected items were in such close proximity that they either got puked on, sneezed on, or exploding body'd on.

While I actually enjoyed the film a bit, I had s lot of issues with the movie, too. First of all, we still don't know where the virus ACTUALLY came from. Was Porter some diabolical genius who manufactured it (unlikely)? Did he also have the cure for it, which is what made him immune to it? Did he kill the remaining people so that he could infect the world and then capitalize on the vaccine? All of these are probably unlikely, but I still don't get where the initial infection came from. At least in CF 1 & 2, we see how the initial infection was brought to the population that the movie is focused upon. Did Edwards create and/or release the virus so that HE could capitalize on the cure? Patient Zero just seems like a misleading title, since we actually get no real clue of how it got there/started. I also find it incredibly ludicrous that they'd take a bottle of water from a questionable source after just having encountered what they had, and, even more ludicrous, that they didn't noticed that their water was blood tinged and contaminated, which I kinda suspected the moment Porter handed them the water.

Anyway, yeah, still fluid and mucous-membrane based as of this installment.