False Positive Tests for STDs

March 7, 2018

What’s a False Positive Test?

STD testing, and diagnostic testing in general, is not a great science. Occasionally people test positive for diseases they do not have, something that is called a false positive test. False positives occur because no diagnostic test is ideal. As scientists layout diagnostic tests which can find smaller and smaller evidence of a disease, they also open the door to accidentally detecting something which isn’t actually there.

It’s a tough balancing act. 

Test quality is always a matter of balancing the need to try and catch as many cases as you can (sensitivity) with the requirement to not diagnose people that aren’t really sick (specificity.) Unfortunately, it’s difficult to design evaluations that are good in both, so scientists try and figure out which result is worse in any given situation – that a false positive or false negative and weigh things accordingly.

Generally, if missing a diagnosis could cause long-term harm, and the remedies for a state aren’t particularly dangerous or unpleasant, physicians would rather risk false positive evaluations. In such situations, it’s better to over diagnose and more than cure. But if being diagnosed improperly could result in serious harm — physically through the use of harmful remedies or emotionally because of the stigma associated with an infection — then it is better to under diagnose and attempt to catch the disease at a later stage when the condition is more apparent.

Clinical Concerns About False Positive Herpes Tests

Doctors are very concerned about false positive herpes evaluations. Since herpes is quite common, and many people never have symptoms, they don’t look at missing a diagnosis to be a very major deal. However, the disorder is so stigmatized a false positive test can be life-changing in a very negative manner.

Thus, they are frequently reluctant to check for the virus in the absence of either symptoms or a known vulnerability, even though blood tests do exist.