My partner and I have been together for 12 years. Recently, my partner tested positive, and I negative. My question is why has he been infected and I have not shown positive? Looking back, he may have been infected for a few years ago when we had outside sex partners. I am going to re-confirm my status with blood work. But, I'm so afraid for our future, and what more news we can bare. Can you put some light of everything that has happened?

Thanks for posting your question. If your HIV test indeed continues to be negative, you and your partner will become what we call a "discordant couple," meaning that one is positive and the other is negative.

Discordant couples are not rare, although many may have engaged in unprotected sex for months or even years. There are many factors that can influence this. HIV is not 100% transmissible with every sexual contact. For some discordant couples infection may take only one unsafe exposure, for others a few, and for others many unsafe exposures. This is because HIV transmission may be influenced by the amount of virus present in the positive partner at the time of the sexual contact, the type of sexual exposure that took place, time of exposure, fluid exchange, the presence of other STDs (such as herpes), the status of the negative partner's immune system, and believe or not, even circumcision on the negative partner for some specific contacts; among many other factors.

In addition, albeit rarely, a few people are able to resist becoming HIV infected, or their immune system may make it very difficult for them to get infected, because of their own immune system mechanisms (which I am not going to discuss.) Again, this is a very rare event, and it is unlikely that this will be your case. So, if you are negative indeed, do not assume that you are part of that group and avoid exposing yourself.

The fact that you have not become infected yet, despite repeated unsafe exposures, does not mean that it will not happen tomorrow. You can still enjoy safe sexual encounters with your partner by using condoms, and maybe he could consider starting HIV medications to further lower his viral load, and thus the chances that transmission to you will occur during intimacy.

By the way, HIV is a very controllable disease these days, and although you are better off remaining HIV negative, there are plenty of new treatment options for your partner. Good luck to both of you!