EDIT: Apparently mistake and it was someone else returning from vacation:
In Garmisch wurden mehr als 1000 Menschen auf das Coronavirus getestet. Der Landkreis macht eine 26-Jährige für einen größeren Ausbruch verantwortlich.
m.tagesspiegel.de
26 year old woman, went to several bars/restaurants with symptoms.
Trotz Corona-Symptomen war eine US-Amerikanerin laut Landratsamt im Nachtleben von Garmisch-Partenkirchen unterwegs. Der Landkreis verhängte neue Einschränkungen.
www.zeit.de
It's not the travel, its the lack of testing. We should test people coming in and going out. Then only allow entrance after a negative test can be shown no older than 3 days. If someone is however tested positive, they should be kept in a quarantine. This can easily be checked by calling their homes at irregular intervals. Of course this doesn't work on flights, in which case you'll just have to extend your vacation (it's a risk you take.. sorry) or cancel it (again.. risk you take). But within the EU, and traveling by car? This should be perfectly workable. States do have to share their testing results with each other though.
But right now every state is just using xenophobia and "QUARANTINE!" as easy fixes that aren't really fixes. Here in Norway, NOBODY get's the test as there is a risk for a more extreme quarantine after travel. As "there might be a false negative!". So what's the point in testing then? Humans work weird and a reward like "you can end your quarantine if test is negative" would work really well to get a grasp on what is entering and goes out.
On top of that: In Finland I hear they want mandatory testing for all foreign nationals entering (even those that live in Finland) that they also need to pay for BUT not for Finnish Nationals? Any Fin can confirm this? As that is extremely stupid. A Fin visiting say.. Spain, would not need testing.. but a Swede living there doing the same "OMG TEST!". Do they really think the Virus looks at your place of birth first? Sorry rant.. just seemed so silly.
