I have a friend who found out that she was HIV positive. She was dating this guy and she was told by some friends that he die of AIDS. She instantly got tested for HIV and she tested positive. However, she has been dating this other guy for approx. 4.5 years, and he also tested for HIV; however he tested Negative. Is it possible, that he really does not have HIV, or will it show up later. How is that so???

First of all, it is possible that he is infected and still got a negative HIV result if he had been tested during the window period. It takes up to three months to develop a detectable level of antibodies as measured by antibody screening tests. If someone is tested less than three months after their last exposure, the test may not be accurate. It is important that this guy has an HIV antibody test performed three or more months following his last exposure and to avoid any significant exposures during the window period. It is rare that someone would take six months or longer to develop a detectable level of antibodies.

Some people do not get infected when having unprotected sex with their HIV infected partners. The reasons behind this are not always clear, but it does happen. Studies conducted in the United States have suggested that insertive (male)partners in vaginal sex are at less risk for infection than the receptive partners (the person in whom the penis is inserted). However, transmission is possible to the insertive partner (as demonstrated by the dramatic levels of infection among heterosexual men worldwide), so condom use is important. Other hypotheses exist to explain the lack of transmission in certain cases: circumcised men may be at less risk than uncircumcised men when engaging in insertive sex; some people may be less prone to infection due to inherited genetic resistance; the lack of STDs may reduce a person's risk for infection, and; the infected person's viral load may play a role in the likelihood of transmission.

If your friend's partner remains uninfected, that's a good thing. It will be important for them to figure out how they want to reduce his risk for infection in the future. However, it is important to not assume, based on their experience, that other people may have the same good fortune that your friend's partner did if they continue to have unprotected sex.

RMK