I know you may hate such kind of questions, but please? We are really worried...
A toothbrush can be a problem because it can have blood on it and if the other person's mouth has bleeding gums, blood can enter the bloodstream. No one here has ever said blood transmission is no risk. I believe you are misunderstanding. Blood transmission is the only risk. Infected blood has to get in to the bloodstream of a non-infected person to transmit the virus.
People who are uneducated often think that touching something a hepatitis person has touched, can make the virus enter through something like chapped hands. There is no risk there. Most of us have families and have had hep C for years, even decades, and our families do not have hepatitis C. Blood enters the bloodstream from things like sharing IV drug needles and works; getting tattoos or piercings using unsterilized needles and inks; having rough sex that causes bleeding, using someone's personal hygeine articles like razors and toothbrushes, etc. There is no documented case of the virus being transmitted the way you describe. However, I would tell the roommate to be more careful about cleaning up and to cover his wounds with a bandaid.
I am sure someone will come along with more advice for you.
Thank you very much for your explanation. But I still didn't understand the difference between contaminated toothbrush and contaminated doorknob......they can both bring virus into my wound, then bloodstream can't they? Please allow me to describe again, specifically.
I fear that, he squeezes pimples, blood on his hand(very little maybe invisible), then he touches the doorknob, I touch the doorknob, then I squeeze pimples. Does this series of actions may leads to blood contact? Or does this series of actions just lessen the virus to on risk?
Blood hanging around on exterior surfaces such as a doorknob doesn't usually stay as active as it would if you stuck an infected needle in a vein.
The situation you are describing is rather benign. If your scenario were true this virus would become an epidemic and we could never leave our home as everyone would touch a surface.
It's more immediate blood to blood contact. If your roommate shaved and was bleeding on his razor and then you used it and bled also, then yes you could test positive. Even having sex is low risk. Both partners would have to be bleeding in order for transmission to occur.
Eating, kissing, for instance are considered non risk. Perhaps it could possibly occur if everyone is bleeding, but not likely. You can equate it to getting struck by lightening to some degree. Can it happen if you go outside and its raining? Guess so, but not likely.
Thank you for the explanation.
Livelife gave you an excellent explanation. I think the difference between a contaminated doorknob and a contaminated toothbrush is....a doorknob can't poke you and get blood into an open wound. A bristle on a toothbrush can poke your gum tissues and get virus in to your bloodstream. Also, it is highly unlikely a doorknob would become contaminated in a way that it could transmit the virus.