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Several questions about HIV transmission needed to be clarified

Question: 

Hello Helpline,
I have several questions that I need you guys to explain in details for me to ease my anxiety (please answer my questions in my order and as detailed as possible):
1. I learned in this site that HIV virus dies AS SOON AS it (in the fluids that contain it) hits the air (oxygen) and no longer to infect other people. But please explain me why one day I went to HIV test center and took a rapid test (got the negative result after 30 minutes), the doctor used a syringe to get my blood out and then she made the blood out to a tube (sorry my English is not very good but I hope you understand what I am saying) and then she continued the test procedures. I just wonder once the blood had been got out of the syringe to the tube (in the lab), even though in few seconds, it hits the air for sure. Does this kill the virus in my blood and affect the test results? what is the difference between an inactive virus and a COMPLETELY DIED virus? both of these types no longer to infect, right?
2. I got the test results of a rapid test HIV-ab (got the results within 30 minutes) is negative. And my risk activity happened over 2 years ago. So my test results are 100% reliable right?
3. Finally, I also learned that HIV virus need a DIRECT ACCESS to blood stream to infect. I wonder if a small cut that is only millimeters in size and only slightly bleeds (not much, stop bleeding after few seconds or minutes and does not leave scars) like a shaving cut caused by a razor or paper cut, are those cuts consider an access for virus to penetrate to the body?

Answer: 

Hi there!

Thanks for contacting us with your HIV-related questions.

These are excellent questions. I appreciate how you read through our website and looked for answers before posing your questions. Also, your English is excellent and easily understood.

1) You’re correct – the HIV virus dies once it leaves the closed system of the body and is exposed to the air. However, when testing occurs the syringe allows the closed system to be extended because it takes the blood directly from inside your body and puts it into an air tight test tube. This is why the HIV can be transmitted through shared needles used for injection – the blood is never exposed to the air and thus the virus remains alive.

However this information is irrelevant to the question you posed about your test results, because the Rapid test looks for the antibodies in the blood, not the antigens. The antibodies are produced by the immune system as a response to the identification of a foreign object in the blood – like a bacteria or virus’. The rapid test looks for any of the HIV antibodies that would have already been produced by your body if you had contracted the virus. These antibodies would remain in the blood after the death of the virus.

It is worth noting that some other HIV tests also look for the antigens (such as the 4th Generation EIA combo test). The antigens are any substance that provokes an adaptive immune response – the virus itself.

2) The World Health Organization considers all HIV tests to be reliable, accurate and conclusive 3 months post-exposure. However many HIV experts use test results at the 4-6 week post exposure mark as a very strong indication of your HIV status. This is because 95% of people develop detectable antibodies in this time. In fact, most people develop detectable antibodies within 21-25 days post exposure. If your exposure happened 2 years ago, and you have had no new exposures in the meantime, then you can absolutely trust these results as reliable, accurate and conclusive.

3) This is a great question. People are often confused as to what constitutes a closed system. Contrary to the internet myths, the HIV virus is quite weak. Basically, it is not able to fight its through your skin or through the clotting that results from the healing processes of a cut.

Also - going back to question 1 - the virus dies as soon as it is exposed to the air. Therefore being dropped on a cut on the outside of your body (like on your hand) provides a hostile environment for the HIV virus and it is difficult for it to survive long enough to enter that cut and infect the host.

When we say “direct contact” we mean an open, fresh and deep wound. The wound needs to be profusely bleeding. A small razor nick or a paper cut would not be qualified as “direct access” because they are only surface cuts and still provide far too much of a barrier for the HIV virus to get through. The wound would have to be large enough that you would be unlikely to continue engaging in any sort of sexual activity because you would be seeking some form of medical attention (think a deep laceration, like a stab wound). Direct contact can also be met through vaginal or anal intercourse, or by sharing needles.

I hope this has helped to clear up some of your confusion! Please feel free to contact us again with any further questions. You can email us at helpline@aidsvancouver.org, or call us on the helpline at 604-696-4666.

In Health, Chantelle, Aids Vancouver Helpline Volunteer