I've seen a few Brazilians (like me) lurking around sometimes, so certainly there are people from LatAm. I'd wager the distribution of countries that read Hacker News and the distribution for people who comment might be slightly different. The distributions linked in another comment seem somewhat unreal to me, but perhaps I'm just imagining every English-speaking person on the internet as an American LOL.

Also, the other comment regarding the time zones is absolutely real. It's a fun experiment to check out Hacker News at unusual times of the day and observe the differences in content and especially in the comments section.