Thank you for your inquiry. From what we gather from the question, you were asking about the possibility of HIV transmission given the event that you licked a public toilet seat.
From the information given, this scenario is determined to be No Risk (HIV transmission is not possible in the given scenario).
In order for HIV transmission to occur, our HIV Transmission Equation must be fulfilled. This would require the presence of HIV positive fluid (semen, blood, vaginal fluid, anal fluid, pre-cum, or breastmilk), with direct access to the bloodstream, through a High, Low, or Negligible Risk activity. In the scenario provided, there equation does not appear to be fulfilled as there was no direct access to the bloodstream (licking an environmental surface does not count as providing access to the bloodstream), as well as no activity (such as needle sharing, or condomless sex) that would provide an opportunity for HIV transmission.
For these reasons, we Recommend that there is no need for HIV screening. Please refer to a health care provider for any other health related questions.
All the best,
AIDS Vancouver Online/Helpline, Cody