COVID-19 TEST RESULTS

NHS Western Isles can confirm that an individual in the Western Isles received a ‘false positive’ test result this week, and is included in today’s national COVID-19 figures for the Western Isles (17.09.20).
 
Essentially, an individual received positive results from a mainland laboratory, which was re-tested through the NHS Western Isles laboratory and was confirmed negative.
 
The mainland laboratory system was designed to provide rapid results for a large number of screening tests.  Where a result is a ‘weak positive’ in someone without risk factors for exposure to COVID-19, a confirmatory test is recommended.  
 
The confirmatory test that is used by NHS Western Isles in the local laboratory is called a Cepheid test which is considered to be the ‘gold standard’ in testing for Covid-19 and is used as the system to ‘retest’ as necessary.  Where this test is negative, the mainland laboratory test is regarded as a ‘false positive’.
 

This is the third ‘false positive’ test result reported for the Western Isles, where confirmatory tests have shown that COVID-19 was not detected. We wish to reassure our local communities that public health risk assess each result and all such tests are thoroughly investigated.