Overuse and improper use of antibiotics followed by lack of proper hygiene practices that would kill MRSA.

MRSA stands for Methicillin-resistant Staphylococcus aureus
As the name indicates, it's an antibiotic resistant bacteria. We get bacteria like this from misuse of antibiotics over time.
------------
It's very unfortunate that this young man was taken so early in his life. I feel for his family.