I went to get a full panel test today at an STI clinic in London.  when i went to the toilet for my chlamydia / gonnorhea swab, the test tube fell on the floor.  I picked the tube up and proceeded with my swab.  The swab did not touch the floor.

However since leaving the clinic I’ve been extremely anxious as to what if the tube fell on hiv positive blood or semen, and what if i picked the tube up and touched the swab / the plastic bit of the swab, and then inserted this swab and infected myself with hiv.  Or what if the swab / plastic bit of the swab touched the test tube that had been on the floor and then I used the swab.  I also obviously touched the door lock when going into the toilet so that is making me nervous too.  I did not wash my hands before taking the test as my arms were full with a coat and scarf, however my fingers themselves did not directly come into contact with my vagina.

Is there any risk of HIV transmission from this scenario? 

Thanks so much for taking the time to review 

There are two theoretical concerns here. First, could the specimen tube be contaminated with bacteria from the toilet floor, making your gonorrhea/chlamydia test false positive? That's not your main question, but it's by far the greatest potential risk. Probably the risk is very low, however.

The possibility you were infected yourself is far less likely, probably zero risk for all practical purposes. First, despite the setting, the chance the floor was contaminated with living/infectious HIV or other STI is close to zero. Same for the doorknob. In the 40+ year history of the HIV/AIDS epidemic, not one infection is known to have been acquired by contact with a contaminated environment. So even if the blood, doorknob, etc had HIV or other viruses or bacteria, you would not have caught them from such an event.

In the future, if something like this happens, you should not provide a specimen, leave the toilet, explain what happened, and request new equipment to collect the specimen. Having not done that, I suggest just waiting for your test result. If it is negative, you won't need to worry about whether the specimen had been contaminated. As for your own risk of infection, I really would put that at zero and would not advise testing. But if you would like the reassurance of knowing you have tested negative, you could do that in the next few weeks. I suggest you discuss this with the clinic then follow their advice on timing. They might agree to an HIV RNA ("viral load") test, which is valid 11 days or more after the last possible exposure; or perhaps more likely, an AgAb (4th generation) HIV blood test and standard syphilis and hepatitis B and C testing at 6 weeks.

In the meantime, try not to worry. Almost certainly all is well. And from a medical/risk perspective you really don't need testing at all -- only to be considered for its possible reassurance value.

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD