sinusitis and tonsillitis are not technically contagious. exposing someone else will not necessarily give them you exact same disease. it is the germs (bacteria viruses) that can be contagious but exposure to those germs will not necessarily result in the same or any disease since everyone's immune system is different. viruses are the most common pathogens and most respiratory viruses that cause sinusitis or tonsillitis are thought to be transmittable by close contact for a day before you know you are ill and for 2-3 days later. mono is a virus that can cause tonsillitis and mono is contagious for a longer period of time. again exposure does not imply that someone would get anything else by a simple cold. strep can cause both tonsillitis and sinusitis and this bacteria is contagious as long as you are contagious or until the end of your antibiotic course. strep will not just jump out of your throat or nose onto someone else but sharing drinks kissing sneezing in someone's face can certain expose others. if their immune system is susceptible to strep they can certainly get it. sinusitis and tonsilitis are not contagious diseases. so you may not worry of affecting anybody in your close vicinity.
how long are you contagious to other people when you have sinusitis and tonsilitis?