It is when a male or female put his her/his mouth or tongue in contact of his/her partner anus, vagina or penile.

Deep French Kiss:

Yes, You could share a sexually transmitted disease with deep french kiss, the longer duration and the deeper intensity the higher chance of transmission. Considering a partner with gum disease and bleeding gum would increase the risk. Please read following article in The New England Journal of Medicine regarding passing herpesvirus 8 in HIV patient causing Kaposi Sarcoma.

http://www.webmd.com/sexual-conditions/news/20001108/deep-kiss-could-spread-cancer-virus

Oral Ejaculation & STD  

There is a false belief that if one receive oral sex but does not ejaculate or not get contacted with semen then there won't no risk for STD. It is wrong.

Oral sex is sex either release of semen is involved or not. There is some risk difference with certain STDs such as HIV or bacterial infection transmission upon contact with semen which would be discussed with you upon your consultation.

Menstruation & Oral sex

If female partner  is on her menstrual period either early stage with very minimal spotting or her heavy bleeding period this would significantly increase the chance of certain STD transmission. Obviously blood borne STDs would likely to pass easier upon you.  

Gum Disease, Lip sore, Dental problem aphthous ulcer & Oral sex

All of the above oral pathology could increase the possibility of exposure to sexually transmitted disease. If you have fissure on your lip or mouth sore or bleeding gum or if you have had recent tooth extraction then by performing oral sex you are at  risk of getting or giving STDs.

For you to understand this concept,  I would say HIV-1 to be 110 to 128 and 132 to 146 nm , so it is about 0.00011 to 0.000014 millimeter. it is so small that you can not even imagine it. It is hardly seen by electron microscopy. In this way by having slightly bleeding the chance of exposure is high to thousands to million of virus depends of viral load at time of sex. 

STD Risk in Oral Sex

Many bacteria and virus could get transmitted by oral fluid exchange or direct mucosa contact You may contract STD by oral sex.  Some example are listed below:

Herpes : You could get or give  herpes by oral sex

HPV: You could get HPV and wart in your oral cavity by performing oral sex on someone who is infected

Gonorrhea/ Chlamydia: You could give or recieve gonorrhea by giving or recieving oral sex. We have seen patients with gonorrhea after just recieving oral sex. You could also get gonorrhea sore troat by performing oral sex on infected person.

NGU: One of the most common STD that you may

contract with oral sex is NGU  Read latest article(Jan. 6, 2006 -- Oral sex raises the risk of a common sexually transmitted disease (STD) called nongonococcal urethritis (NGU)

in men, Australian researchers report.) http://www.webmd.com/content/article/117/112461.htm

HIV in Oral Sex: According to recent study and CDC

"likelihood of transmission of HIV from an infected person to an uninfected person varies significantly depending on the type of exposure or contact involved. The risk of becoming infected with HIV through unprotected (without a condom) oral sex is lower than that of unprotected anal or vaginal sex. However, even a lower risk activity can become an important way people get infected if it is done often enough".

"Nearly half (3 of 8) of these cases reported oral problems, including occasional bleeding gums. Almost all (7 of 8) of these men reported to have had oral contact with pre-semen or semen."

http://www.cdc.gov/hiv/pubs/facts/oralsexqa.htm

Syphilis : You could get infected with syphilis by oral sex, Please refer to our syphilis page to get further info.