hepatitis b or c transmission through cigarette sharing

[fever4]

hi,
i have a pyschological problem  due to the my experience from last year and i am so sensitive to STD transmission, my question is about hepatitisb and c.
Yesderday i was out of cigarette and i smoke my roommate cigarette i mean we smoke the same cigarette, is there any risk for catching hepatitis b or c. i could not ask my roommie whether he has hepatitis b or not because he may think that im crazy,  but im worrying about it.  saw some website saying that unlikely i dont know what the unlikely means. Thanks

[Mememememe77777]

I've heard yes from a trained medical professional. So I'm going with that answer.

[fever4]

thank you very much im trying to quit from smoking.
it is saying in many websites that hepatitis b presents in saliva, so when we share cigarettes more or less my lips may touch the saliva that he left on cigarette filter, thats why i was anxious and still little anxious about it.
also in university of georgia its saying that people get hepatitis b through kissing. im asking because i dont know how the mechanism works in case of hepatitis. what is the difference between kissing and sharing cigarette or glasses?  thank you very much.

http://www.uhs.uga.edu/sexualhealth/sti/hepatitis.html

[stef2011]

quit smoke because more dangerous than those viruses for many persons.......

transmission
hbv sex and blood
hcv blood only