Fortunately, the intelligent people needed to design these genetically-engineered, cocaine-eating mutant bugs already understand this.
Which is why nobody does it. We are FAR from sufficient knowledge of molecular bioengineering to design such a beast with sufficient safeguards.
Unfortunately, terrorists and deep green fanatic don't much care if it happens. For terrorists, they believe that "Allah will protect his own", and for the deep green fanatics, human virulence is a feature, not a bug.