I don't think there's any disease at work here: this is the typical look fig leaves take around here in the Fall when the weather starts turning colder and wetter. Or folks plant them in their gardens and overwater them.
In short it's a standard reaction to less than optimal growing conditions.
I also see your plant is potted, which is something figs don't really like, chiefly because it's hard to find an off-the-shelf potting medium that suits them. Too much compost, too much sphagnum moss... figs don't like that. They are adapted to low quality, rocky soils.
Finally there's another consideration: isn't Mexico City 7,000ft above sea level or something like that? Here we are considerably lower than that and we are at the upper limit where they can be successfully grown.