Hello my test came back negative but unfortunately immediately after I had another possible exposure. I was at a public trail near my house and when I was throwing away a water bottle my keys fell into the trash. There was a semi closed lid only open from the front and back to place the trash and closed everywhere else. I put my arm in (I had a sweatshirt on but no gloves) and tried to be very aware of any sensation especially a cut or prick while I retrieved my keys. I thought I walked away unscathed however I am concerned of the possibility that somebody may have placed a needle in the trash can near the edge or around the perimeter of the inside of the lid so that somebody would get injected and infected. At the time I only felt what I thought was the trash lid and it’s edges but now I’m concerned that I may have been injected. I didn’t see any blood when I checked my arm about 15 minutes later but I had a sweatshirt and it may have wiped it off when I took it off. I didn’t see any obvious wound besides where I had my blood drawn and a tiny pin prick red spot. If I had been injected inadvertently and didn’t feel it, would a RNA test at 11 days be sufficient enough in terms of testing? What would be the chance of infection from an injection incident?

Welcome back to the Forum although I must point out that in an earlier reply Dr. Handsfield suggested that you not worry as much as you seem to about HIV.  I feel the need to point out to you that HIV is a RARE disease that is rarely encountered in the activities of daily living and that even with true, biologically plausible exposures, most exposures do not lead to infection.  Infection through inadvertent contact with used needles outside of health care settings is virtually unheard of.  In the situation you describe, there is NO evidence that you were stuck since if this had occurred and led to a meaningful exposure, there would have been a puncture wound and evidence of bleeding.  You did not ask but if you'd asked me whether or not you needed testing at all, my response would be an emphatic no.  If you feel you must test, a negative PCR at any time more than 11 days following exposure would be strong evidence that you were not infected.  In my opinion however, in the situation you have described, would be strong evidence that there was no infection.  (Please feel free to review our earlier exchange on the topic of why some experts recommend repeat testing with a 4th generation test at > 4 weeks following a negative PCR, I will not repeat it).

I would suggest however that you reflect on why you are worrying so much.  EWH

Yes, a puncture wound would resemble the site where you had blood drawn.

IF you sustained a needle stick from a recently used needle which had been used by an untreated, HIV infected person your risk of infection would be in the neighborhood of 1%. 

There would be no risk for HIV from a "poke" with a plastic fork

I look forward to hearing the results of your RNA test.  I am confident it will be negative. EWH

Getting a flu shot will have no effect on your tests for HIV. 

While I would not use the terms you have used, I would agree that you are far more concerned about the events you describe than are logically warranted based on available science.  You stated "I know infection from environmental needle encounters are rare but I’m also aware that means they are still possible."  I would argue that the risks are close to unheard of and that while it is "possible" that you will be struck by a meteorite falling from space today, it is not a realistic concern.  I would put your risk of HIV from the events you describe is just about as likely as being struck by a meteor.  As I have tried to indicate earlier, I would not be worried about the events you describe in the least.

I am not sure where you saw the 3% figure regarding risk for HIV from a needle stick (something that you have no evidence that occurred). Scientific studies give a variety of different transmission rates which are impacted by many variables including how recently the needle was used by the infected person, the amount of blood transferred, the amount of HIV in the blood of the person with HIV, and much, much more.  1% is an average figure.  many studies show the risk to be substantially lower. 

If I were truly concerned about a known needle stick from an untreated person know to be infected with HIV, I would get an RNA PCR test no sooner than 11 days after the event.  Standard recommendations are to then follow that test with a 4th generation at 4-6 weeks. 

I hope this information will be helpful to you.  As this is my 3rd reply to this series of questions, as per Forum guidelines this thread will now be closed without further replies.  I must also warn you that our Forum limits anxiety-driven, unrealistic questions about STIs, including HIV.  I have done my best to address your questions and concerns.  I must warn you that further questions of this sort may be closed without a response and without return of your posting fee.  I wish you the best.  EWH