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PCR tests could result in false positive results for up to 90 days

Roboscientific VOC sensing technology reduces risk of false positive and negative tests

Posted: 9 July 2021

Posted In: | News | Our Tech |


Fascinating interview last night on Phil Williams Show on Times Radio with Dr Bharat Pankhania, Head of Public Health Teaching at Exeter Medical School.  He was explaining how PCR testing can give false positive tests up to 90 days after infection. 

The Government testing protocol for travel is to take a test at Day 2 and Day 8.  Dr. Pakhania explained that the coronavirus infection will be most likely to give positive test from Day 5-7 so a Day 2 test is likely to give a negative result even if you are infected and by Day 8, you will have been infectious for 2-5 days before you get the result.

As worrying, the positive result will continue for up to 90 days even though the virus is a spent force within the infected person.  This is because there could still be remnants of the virus RNA within the body of the infected person for all that time!  This could mean that travel plans could be  disrupted and self-isolation a requirement for far longer than is needed.

Roboscientific's VOC sensing technology looks for the metabolic changes caused to the VOCs you emit by the virus.  This is why we achieved 98-100% accuracy in the recent trials conducted with London School of Hygiene and Tropical Medicine.  It means that we are far less likely to get a false positive result or a false negative result because our sensors respond to the active virus within the body, rather than looking for signs of the presence of the virus.

We are completing trials and development of our Covid Air monitor, which samples the air for the presence of in infected person in a room.  The aim is to have it available very early in 2022.  A breath test which will also deliver results in real time is also under development.  As  testing  looks to be with us for some time, we hope we can make it faster, easier and more accurate, helping to get life back to normal for us all.