I am doing some research on my own about the risks of oral sex and HIV. Now, I have read on multiple questions that there is no risk in receiving oral sex. I see both of you have state that the risk of getting oral sex from GIVING blowjobs is low and rare, but there have been documented cases of transmission. I know the internet is not our friend when it comes to medical information, but I have searched multiple sites, do you know roughly how many cases have been proven to have been transmitted by GIVING oral sex to a penis? I did find on one HIV site ( I do not know if it is a legit site) that there have been no proven cases where WOMEN contracted HIV from giving oral sex on a penis- only MSM, is this true? The CDC states that in order for HIV transmission something very usually has to happen- including throat infections, cuts or sores in the mouth. Do you agree with this?? Lastly, which maybe a repetition of my previous sentence, is the throat considered a delicate mucous membrane? 

When HIV is transmitted regardless of route, is it due to tears in the mucous membrane which leads to access to the blood stream or can HIV magically get through the delicate genital membranes.

Thank you for your time and energy 

Correct, there have been well documented cases of HIV transmission penis to oral, i.e. by the receptive partners in fellatio (or if you prefer, the person giving a male partner a BJ). Based on how people with HIV believe they were infected, CDC once calculated the risk to be one chance in 10,000:  that is, giving oral to an infected male, with ejaculation in the mouth, has one chance in 10,000 of catching the virus. That's equivalent to giving BJs to infected male partners once daily for 27 years before transmission might be likely. For the opposite exposure -- i.e. for penile partner in oral sex with an infected partner, there has never been a proved case. Based on how people thought they were infected (which often is wrong), the calculation was one chance in 20,000, if the oral partner has HIV. There has never been a proved case of HIV transmitted by cunnilingus -- oral vaginal contact -- to either partner.

It is not true that oral to penile HIV transmission has occurred only in MSM. Some women have been infected in this manner. I am unaware of CDC statements that "something unusual" is necessary for it to happen; mucus membrane tears are not known to be needed. Such things may or may not slightly raise the risk, but oral exposure to semen carries at least some small risk. The virus can penetrate and establish infection through intact mucous membranes.

Perhaps a simple way to keep all this straight is that almost all sexual transmission of HIV involves penile-vaginal or penile-anal penetration; and that oral-genital and oral-anal contact are sufficiently low risk to be considered safe sex, with condoms or other barriers considered optional and not required for sexual safety.

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD

Do you happen to know the number of people who have been infected by performing fellatio or a guess? Have you ever diagnosed a person with HIV whose only exposure was oral sex? 

Thank you for helping me conduct my own research  

I can't estimate the number of persons who have acquired HIV by performing fellatio. I've not personally been aware of an HIV infected person whose only possible exposure was either giving or receiving oral sex.