Watching Planet America and The Late Show last night, they both talked about how these shut down and travel ban measures are not for the containment or elimination of the virus, but is to mitigate (slow down) its spread because no country has the hospital resources to cope with even the best estimates of infection. Most western countries only have intensive care resources to cover 0.1 to 0.5 % of the population and this virus will give about 20% of infected people serious to fatal symptoms (80% will experience little more than cold symptoms). And most of those beds/resources are always in use from other medical conditions which means less available for a plague. So even if agencies know they can't stop the spread of the virus, they know that we need to spread out the infection rate over a longer period of time so that our hospitals can keep up. Already in Italy, hospitals are forced to triage - which is to decide who is being treated because they don't have enough resources and beds to treat everyone. Not to mention all of the non-virus issues needing intensive care that may not survive if they are full of virus patients.

Its just better to lie to the general public to prevent a panic from the over paranoid or less educated (or misinformed through social media).

Just stay safe everyone and be vigilant with limited contact with others and wash hands often.