Pestilence: deadly epidemic disease; Back in the old days, there would usually be a pestilence.

Contamination; the act of being contaminated; If this is the case, there may be a contamination at the scene.

Repulsive: (synonym) unpleasant; The odor in the classroom was very repulsive.

Proboscis: an elephant’s trunk; The proboscis swung back and forth repeatedly. 

Parasitic:(synonym) bloodsucking; There are many bugs that can be parasitic.