By now. most of us know how HIV can be transmitted. Transmission routes include:
sexual contact (oral, vaginal or anal)
during pregnancy, delivery, or breast feeding
The most common transmission route is sexual contact despite simple ways to prevent such transmission. Safer sex techniques, specifically using latex condoms each and every time are essential in preventing the transmission of HIV.
So the question remains; do HIV positive partners need to use condoms? Obviously, sexual contact between a person who is HIV infected and one who is HIV negative requires condom use to protect the uninfected person. But most people are surprised to learn that sexual contact between two HIV infected people also requires a condom. Different strains or types of HIV can be passed between two HIV infected people ("HIV Re-infection"), making treatment of the infection even more difficult in both For instance, if person "A" has an HIV type that has been responsive to therapy and person "B" has an HIV type that hasn't, passing that type of HIV from "B" to "A" will make it harder to treat person "A", possibly making therapy ineffective in person "A" as well.
In addition to preventing HIV re-infection, condom use is also important in preventing the transmission of other sexually transmitted diseases such as syphilis, gonorrhea, and chlamydia.