Some blood tests include a 'Cut off Index' value, which indicates the level of reaction that was detected during the test. In most cases results above 1.0 would be considered ‘reactive’/positive result, with ‘non-reactive’/negative results seeing a COI value below 1.0.
In some cases your result may be over 1.0 but only by a small margin. Officially this is considered a ‘reactive’/positive result, however due to the very high sensitivity of this test low results are often not confirmed once further testing is carried out in clinic (and are therefore a false-positive).
Many results with a COI value lower than around 10.0 do not confirm in clinic, however it is also possible these low-level results may be due to a very early infection. Therefore, it is still important you attend clinic for a full blood test to be sure of your status.