Chikungunya & Dengue

........ So yes, Holy Mole, come prepared. I don't want to be alarmist but the demographic of NOB visitors has gotten older and we are more at risk of long term side effects.

I don't think it's alarmist at all: this information is alarming. Guerrero may have declared a state of emergency with respect to chikungunya, but it seems the World Health Organization isn't on Guerrero's mailing list. A brief check of the WHO website makes only a casual reference to chikungunya having spread to "the Americas". Go to the WHO's list of "outbreaks" of chikungunya, and you'll see:
Aug/15 - Spain
Oct/14 - France
Dec/13 - French Caribbean
Oct/06 - India
March/06 - SW Indian Ocean
Feb/06 - Reunion Island
and yet the numbers you have alluded to, in just one small municipality in Mexico, constitute a full-fledged health emergency. Or am I being alarmist?