Virulent

Adjective

1. Of animals, plants, or substances: extremely venomous or poisonous.
2. Extremely hostile or malicious; intensely acrimonious.

   "The politicians were virulent in their hatred of the president."

3. Of a disease or disease-causing agent: malignant, able to cause damage to the host.
4. Of a pathogen: replicating within its host cell, then immediately causing it to undergo lysis. .mw-parser-output .defdate{font-size:smaller}