I would not be offended by the blood donation thing. They generalize based on administrative regions (Amazonas in this case) and not whether you visited a big developed city or not.
I had a similar blood donation issue for visiting a particular island in the Philippines, and could not donate for 4 months.
It is funny there is no similar treatment about TBE (tick disease) which is predominantly an European disease and very dangerous and much more common than Malaria is in most (all?) South American countries...
https://en.wikipedia.org/wiki/Tick-borne_encephalitis
There is a vaccine available for TBE. I got it. It is expensive, and my insurance won't cover "travel vaccines".
https://www.cdc.gov/tick-borne-encephalitis/prevention/tick-...
$1,200, wow that is pricey!