The Mexican public health system sucks.
The private health system is great, but expensive, especially for a country where minimum wage is 5 USD per day. Not hour, day.
This has created a culture in which most people avoid going to the doctor unless it is absolutely necessary. For example, say, when you have been experiencing a 40 C (104 F) degree fever for two or three days. By this time, it's been said, antivirals are not as effective. The result: 19 confirmed deaths in Mexico.