(especially of diseases) tending to spread from one person to another

contagious (disease)

(of a disease) spreading by contact

communicable

causing, likely to cause, death

causing end of life

causing destruction; fond of, in the habit of, destroying

injurious, devastating

extremely unpleasant

nasty, obnoxious

causing discomfort, trouble or annoyance

bothersome, troublesome

harmful

deadly, injurious

(of smell, behaviour etc) very unpleasant

offensive, repulsive

extremely harmful, causing distress

bad, hurtful

having poison; causing death or injury

harmful

causing, caused by infection (with disease germs)

harmful

causing worry, unhappiness, difficulty

bothersome, worrisome