Why don't you say clearly that HIV could not be passed when it is outside the human body? It is not validthat opinion or you want to keep people afraid of getting infected by every case? Could you explain why HIV is a difficult virus to get?
There have been studies that have look at old used syringes and have found viable HIV in these. Similarly, infected donated blood in countries that do not screen for HIV is a risk as are unsterilized surgical instruments and such. So, it is not appropriate to say that it is impossible for HIV to be transmitted from such a syringe. But transmission from surfaces such as those found in a bathroom, men's bookstore, dry sex toys, etc do NOT pose a risk of infection. HIV is transmitted almost always from person to person directly.
For HIV to infect a person the stars must align in a specific way. The virus has to evade multiple levels of host defenses to gain access to cells to enter and then use to replicate. Our skin is an excellent barrier to HIV. Even our mouths have antibodies that protect us and HIV that is inserted in the mouth typically does not stay there long (spit out or swallowed). In areas where the virus can be injected in large numbers and stay put (the blood stream via injection of infected blood, the vaginal and cervix after sex, the rectum after sex) it has a greater opportunity to find a way into our systems.
Recall that HIV is a virus that evolved in another species and the jump to humans comes with some costs. That may also explain why HIV is not even better at infecting people. DW