dirty, pestiferous -- (contaminated with infecting organisms; "dirty wounds"; "obliged to go into infected rooms"- Jane Austen)
pestilent, pestilential, pestiferous, plaguey -- (likely to spread and cause an epidemic disease; "a pestilential malignancy in the air"- Jonathan Swift; "plaguey fevers")
annoying, bothersome, galling, irritating, nettlesome, pesky, pestering, pestiferous, plaguy, plaguey, teasing, vexatious, vexing -- (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")