Captions at the beginning of this video explain how the man came by his nasty head wounds and why they are full of maggots. I had to painfully type all the gibberish out from the video and paste it into a translator to make some sense of it. The original text in Spanish reads this:
El siguiente caso ocurrio en Cancun. Este hombre fue asaltado y macheteado por unos pandilleros quedo tirado inconsiente y herido, expuesto al sol y la lluvia por 7 dias tiempo en el cual las heridas se pudrieron y agusanaron. Vean el resultado.
English language translation I got:
The following case occurred in Cancun. This man was assaulted by a gang machete and left lying unconscious and injured, exposed to sun and rain for 7 days at which time the wounds were rotted and agusanaron. See the result.
It would appear that the video was filmed in the popular tourist resort trap of Cancun in Mexico. The man was probably attacked by a machete wielding gang that slashed his head up and left him with no aid to die in the bush. The man survived but not before maggots settled in his machete wounds. The only word I could not find a translation of is agusanaron. I have no idea what it means however the captions make pretty good sense even without it. Check the video out: