Thank you for providing this service. I have a question about a blood draw I had about a year ago in Belgium. I asked my doctor for a Hiv test, with blood drawn from my vein. They did a hiv-antibody test. The hiv antibody test result was negative. No other tests were performed like wbc or CRP or anything else. My question is the following: the doctor that took my blood was still in training and had difficulties getting the blood out of my vein. She poked me a few times with the same needle in my right arm and when that didn’t work she took my left arm and used the same needle and tube (i don’t really know how it works, i mean the same equipment) she used on my right arm to finally draw blood from my left arm. Can this interfere with the HIV test? Like air exposure or something? Is my negative HIV test result still valid and reliable? 

Thank you!

Starting only with the title you chose for your question and the opening sentence:  Assuming standard procedures and equipment, having blood drawn never is a risk for HIV or any other blood borne infection. I cannot imagine you are at risk for anything.

Now I have read the rest of your question. It turns out you're most concerned about whether this somehow affected the validity of your negative test result; I'm glad you're not apparently worried about acquiring a blood borne infection like HIV or hepatitis B virus. That's the main concern of most such questions on this forum; yours is the first I recall asking about test reliability.

I'm sorry to hear the physician who drew your blood had a bit of difficulty; perhaps she is early in her training and experience. But there is nothing in your description that suggests anything that would alter the reliability of your test result. Blood exposure to air makes no difference -- indeed, blood to be tested has lots of air exposure in the process of setting up the test. It's not a problem.

FYI, at one time -- like when I was a medical student and resident many years ago -- almost all physicians drew blood very frequently and generally became highly expert at it. Nowadays blood is drawn primarily by trained technicians and doctors have less experience. Most future blood draws you have probably will be by trained non-MD persons, although this might vary with practice standards where you are, especially if you're outside the US.

I hope this reply has been helpful. Let me know if anything isn't clear.

HHH, MD