Invalid Point of Care HIV Tests
An invalid test is a rare, but possible, outcome of a client test. Several examples of the appearance of an invalid test are shown on the Interpreting HIV Test Results resource card.
An invalid test is most likely to occur if too little blood is collected during testing. However, an invalid result might also be due to some deficiency in the test kit or if the client has some, relatively rare, immune condition. Be reassuring, an invalid test is not an indication that the person may be HIV-positive.
What to do when an invalid test happens?
- Explain to the client that the test is invalid. Reassure them that this is most likely a problem with the test. It does not suggest that they are HIV-positive. Ask for consent to repeat the test.
- Do not discard the test membrane. If possible, take a photo of the invalid test result. An incident report will need to be made for the invalid test, and this picture will be part of the investigation.
- If possible, and if the client consents, have the quality assurance lead or another testing colleague on hand to help read the second test.
- If the second test produces a valid result (the control spot is evident), proceed to counselling the client based on this result
- If the second test is invalid, recommend the client have a standard HIV test, in order to obtain a valid result. If the client consents, draw blood for the testing and submit to PHOL.
Follow-up on an invalid test
If a single invalid test occurred:
- Notify the quality assurance lead
- Record the result in the incident log, and carefully consider what may have caused it in the log entry
- Keep the photo in case the QA lead requests it
- Record the test as invalid on the daily log; however do not submit a requisition to PHOL for this test as it was not a valid test
If two invalid tests occurred:
- Notify the quality assurance lead.
- Keep both membranes and share the photos with the quality assurance lead as an investigation will be necessary.
- Notify AIDS and Hepatitis C Program staff and submit images of the results.
- Record the results of both tests on the daily log along with the referral for standard testing to PHOL. (If the client does not consent to having standard testing done, do not submit a requisition to PHOL as no valid test was done).
- Record the results in the incident log, and work with the quality assurance lead and AIDS and Hepatitis C Programs staff to determine likely causes; record your conclusions in the incident log.