Huge region of the country.
When the church saw this, they decided to pull all missionaries out in case the lockdown spread.
As for your friend in Argentina, my statement was others it seems based on personal accounts of people having kids come and some stay it all depends on the location and also the health of the missionary.
For example we had a CB member whose daughter was sent home from Australia because she has some mild form of Asthma, but other missionaries were not sent home from that area.