Thank you for the answer and the links.
In my case however they took two vials of blood. They told me it was sent to a lab for further testing (they did mention vaguely hemoglobine and cholesterol testing). I read STD's would be disqualifying in general if the effects would affect the normal functioning of a person and HIV would be disqualifying in any case.
So I pressume that at least they would test it for HIV? And I am reluctant to go see a GP and get tested for any STD. It is still quite a taboo and the social pressure is quite killing for me. So if it would be something they have tested for, I can be relieved to know that I do not have any. In the other case I know that at least I do not have any signs (as of yet) which would indicate I have any STD, as I pressume this would show up in urine/blood as organs would be malfunctioning.
But if they do not test for any STD, well that would still leave me with a chance that I could have any. In that case I will get tested some day, just to be sure, because I did take some risk in the past and I read that something like Syphilis could take years to develop and become really serious if left untreated.