The scenario: If I get infected by the HIV virus today, how long it takes to start infecting/passing the virus to others? The story: I had a one-time unprotected sexual encounter with a high-risk woman one month ago. Then, I had unprotected sexual intercourse with my wife the day after, then the week after, and then three weeks after. Assuming I got the HIV virus, what is the risk, if any, of passing it to my wife during any of those three intercourses? Your feedback is well appreciated.

There are many variables that will determine infectivity and transmission. There is no way to predict exactly when the virus is going to be transmitted.

Let me tell you what I know from my research. When HIV enters the body, it fuses with CD4 cells -- critical cells in a person's immune function -- and then travels to lymph nodes within two days. Lymphatic tissue is the main reservoir for HIV. In about 5 days HIV will enter a person’s circulation and disseminate throughout certain systems in the body. HIV reaches peak blood levels in about three weeks, a time when someone would be more likely to transmit the virus to others. This is approximately the time when someone would experience acute retroviral symptoms.

Some impressive recent studies show that rates of transmission are correlated to the levels of virus in plasma/blood. Here's the logic: the higher the viral load, the more virus there is in bodily fluids, and therefore the greater the chance of transmission.

I would say the risk of transmitting HIV to your wife probably increased with each episode of unprotected sex, but only if you had been previously infected.

It sounds like this situation must be stressful for you. If you are going to have sex outside of your marriage in the future, you would save yourself a lot of stress if you used condoms. If you don't, it would be important to figure out how to address this with your wife so that you don't put her at risk for HIV or STDs as well.

RMK