pestilence

(noun) a serious (sometimes fatal) infection of rodents caused by Yersinia pestis and accidentally transmitted to humans by the bite of a flea that has bitten an infected animal. Synonyms: plague, pest, pestis.

(noun) any epidemic disease with a high death rate. Synonyms: plague, pest.

(noun) a pernicious and malign influence that is hard to get rid of. Synonyms: canker. Examples: "Racism is a pestilence at the heart of the nation." "According to him, i was the canker in their midst."