Carnival is, was and always will be about the party but back in the second half of 2015 and all of 2016, Zika became the front and center item of concern for all Brazilians and then for the rest of the world.
The below link will take you to my article that I wrote while living/working in Rio heading toward the 2016 Olympic Games. This is a link to open up the article on SDNews.com where it was original published back in February of 2016.