in quesiton 9954, doctor hook explained that 'the squeezing, etc, can impact the results of tests counting the cells in a specimen but for measurement of HIV antibodies (or antigen) the test is not vulnerable to these problems.'

in question 8733, doctor hook said 'that your original positive treponema test was from a finger-stick process in which you needed to squeeze your finger to obtain sufficient specimen for testing.. this not only explains the hemolysis which was noted but may also explain the test result -- squeezing to obtain the specimen may have release "tissue juices" which increase the risk of falsely positive test results"

There is little if any science on these topics. I suspect Dr. Hook was giving common sense explanations for why fingerstick testing might, in theory, have less reliable results than testing blood drawn from a vein. But I am unaware of any actual research on these topics. From your description, the first instance (9954) seems to refer to blood counts ("counting cells"), but not antibody tests (e.g. syphilis or HIV). In the second, I imagine it was speculation to explain an apparent false positive syphilis result. Indeed, it seems that instance was referring to false positive results, and it was for syphilis, not HIV. I see no reason to expect a false negative result on an HIV test done by fingerstick.

All things considered, I think the chance of false results on account of these issues is exceedingly low, probably nearly zero. I really wouldn't worry about it, either for HIV or syphilis testing.

If you remain concerned, if fingerstick testing is done in the future, I suggest you assure enough blood flow that vigorous squeezing isn't necessary. If you remain concerned about a negative HIV test already done, feel free to repeat it; or have a lab-based test on venous blood.

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

HHH, MD

again on question 9954 dr hook assured that these hiv tests are forgiving and don’t suffer from inaccuracy from squeezing blood out.  

thank you 

I see no reason for retesting yet again, regardless of "vigorous squeezing" (if it happened).

That completes the two follow-up comments and replies included with each question and so ends this thread. Thanks again for your confidence in our services. Best wishes and stay safe!