Does having unprotected viginal sex with someone who has HIV positive mean that you are absolutely going to become infected? If no is the answer, what are the chances/percentage/probability to get infected and what are the things that increase the chances to get infected by having unprotected sex?
Response from Dr. Brondi Luciana
The answer is NO, it is not sure you are getting HIV, but you are at risk. The chances of getting infected during one (1) single episode of unprotected vaginal sex is not very high, around 1 to 2 women in 1000 can get infected in this case.
Nevertheless, this chance can increase if the you have more sexual intercourses, or if the person are having sex with has a high number of virus in their genital secretions, how susceptible you are to HIV infection( depending on your resistance) and the virus type. Some factors can increase the chance of getting HIV during sexual intercourse:
- Having a Sexually Transmitted Disease (either you or the HIV infected partner)
- Not using condoms (like you said).
- If you have bruises, ulcers or cuts in the genital tract or a cervical ectopy (some women have it)
Remember that having unprotected vaginal sex can also put you at risk of other Sexually Transmitted Infections as well and using a condom can help to protect against all these. So, it is better to be sensible and practice safe sex.
Response from Parkhurst Justin (D.Phil)
Having unprotected sex with someone who is HIV positive is risky but it does not mean you will absolutely get it from a single sex act. It is hard to say, however, what the chances are. The chance of infection is based on a number of things, including whether each person has any other sexually transmitted diseases (which can increase the chances of contracting HIV), whether the man is circumcised (which some studies have shown reduces the chances of the man contracting HIV), and also the amount of virus in the persons blood at the time of the infection. The amount of virus in the system (called the ‘viral load’) will change over time. When someone recently catches HIV, they have a lot of virus in their system, and are particularly infectious – the risk of transmission from a single sex act at this point is much higher than it might be at another time. This is why it is so risky to have multiple partners (like having 2 or 3 boyfriends or girlfriends). If the person catches HIV, they may be with other partners while their body has this high level of virus in the period after transmission. This means it can spread much more rapidly. So I can not give you a simple answer. Of course if you use a condom correctly at every time you have sex, you will greatly reduce the chances of infection. If people reduced the number of partners as well, this would help break up the networks which see HIV spread so much in many countries.