Many people come to the HIV Forum asking for a risk assessment. To summarize what constitutes a REAL risk for HIV:
1. UNPROTECTED (INSERTIVE) anal or vaginal intercourse.
2. Sharing IV drug works (needles/syringes)
3. From infected mother to infant in utero or via breasfeeding.
HIV is classified as a STD ("sexually transmitted disease") for a reason. Meaning, one must have SEX in order for the virus to be transmitted in a sexual manner. The virus is a blood borne pathogen, which means it must gain access to the bloodstream in order to cause infection. It can do so via the mucous membranes of the vagina or anus during unprotected sex, or obviously by being directly introduced to the bloodstream during drug works sharing.
HIV is a very fragile virus that requires near PERFECT circumstances for transmission. This means that infection must occur INSIDE the host (body) where the virus is protected from the elements. This is why casual contact, activities such as: sharing drinking glasses, kissing (including deep kissing), mutual masturbation, hugging, etc...are NOT a risk.
It bears mentioning, as we also get these types of questions...that an adult ingesting breast milk in a sexual situation will NOT lead to infection. Infants' immune systems are not yet mature, leaving them vulnerable while nursing, not to mention the obvious difference in the amount an infant would ingest breastfeeding on a regular basis versus a one-time brief sexual encounter.
Unfortunately...there are many way overinflated views of HIV risks. The "blood to blood" scenario comes up all the time. A poster will ask if exposure to another person's blood, or genital secretions to a cut or abrasion will lead to infection. The answer it NO! This kind of situation will not lead to infection for a few reasons. ONE, the "exposure" is taking place "outside" of the body, where the virus quickly becomes inactive when it is exposed to the elements. Secondly, there needs to be exposure to a significant amount of infectious fluids on a vulnerable surface (bloodstream or vascular mucous membrane as in the vagina or anus) in order for infection to occur.
Therefore, being poked with a paperclip, pin, other sharp object....even IF that object had been exposed to an HIV + person, it would not lead to infection. Those types of injuries are superficial, not gaining access to the bloodstream. Remember, the skin has several protective layers...and they work! The microsecond you get a break in the skin, it starts healing from the inside out...creating an effective barrier against many "bugs", including and especially HIV, which is a "sissy" virus! Also, you would only be exposed to the "surface area" of the sharp object...where again, the virus would quickly become inactive once introduced to the environment. How does that differ with the needle scenario for IV drug abusers? They pull back on the syringe after injecting, to be sure they are in the bloodstream. Any blood that is withdrawn into the syringe is essentially preserved, because it is NOT exposed to the environment. Then, the next person injects the infected, preserved blood directly into their bloodstream.
In summary, HIV infection, despite the mania in the general public is RARE and very difficult. If you haven't had one of the three exposures listed above, then you haven't had a significant exposure worth testing for, or worrying about.