It's not the rate. Don't get fixated on the %.
Think about the ABSOLUTE VALUE.
Using an extreme example here.
Saying 50% of my population has a deadly disease is a tragic thing when there's only 10 people in your population. That means there's 5 clean people left.
When you have 100 people in your in population, you'll be fine.
You have 50 clean people.
It's the absolute value ... the number of people that makes you raise and eyebrow.
Brazil I think has like 150MM people living in the country.
America is in the 300MM range.
So although the %'s are exactly the same --- their are FAR LESS CLEAN and HEALTHY people in Brazil simply because of the number of people being less to start with.