pestiferous

1. contaminated with infecting organisms;: "dirty wounds"; "obliged to go into infected rooms"- Jane Austen

2. likely to spread and cause an epidemic disease;: "a pestilential malignancy in the air"- Jonathan Swift; "plaguey fevers"

4. causing irritation or annoyance;: "tapping an annoying rhythm on his glass with his fork"; "aircraft noise is particularly bothersome near the airport"; "found it galling to have to ask permission"; "an irritating delay"; "nettlesome paperwork"; "a pesky mosquito"; "swarms of pestering gnats"; "a plaguey newfangled safety catch"; "a teasing and persistent thought annoyed him"; "a vexatious child"; "it is vexing to have to admit you are wrong"