Abu Dhabi develops saliva virus test that's '100 times more sensitive'

A team of researchers in Abu Dhabi has developed a new saliva Covid-19 test that could prove to be "100 times more sensitive" than the commonly used tests.

Dr Youssef Idaghdour, an assistant professor of biology at the NYU Abu Dhabi (NYUAD), told Khaleej Times that his research team and collaborators have demonstrated that with the new technique, it is possible to overcome two of the main issues in the standard testing protocols: False negatives and the challenge of testing asymptomatic individuals carrying low viral loads.

The research has been backed by Abu Dhabi's Department of Health, Dr Idaghdour said.

False negatives happen because, sometimes, there's not enough viral load in a given sample, he explained.

"This is the case in early stages of the infection, when the patient is asymptomatic, or when they are in the last stages of infection," said Dr Idaghdour, a researcher specialising in the genetics of infectious diseases who has worked extensively on malaria in Africa.

Though the transmission rates among asymptomatic patients are still debatable, it is "almost certain" that they are spreading the virus.

For the team's saliva tests, the PCR technique is still used but it has been modified to increase sensitivity.

"Most testing methods in the market use a one or two-step PCR method. Ours has a three-step methodology and uses a microfluidic device with a nano-technology solution. It is 100 times more sensitive than commonly used tests," Dr Idaghdour said.

'Saliva tests are painless'

Besides its accuracy, saliva tests are painless and non-invasive. "Most people would be happy to move to use saliva testing, granted that the accuracy of the test is not compromised. Also, the use of saliva would reduce exposure of healthcare workers during sample collection. The collection of saliva is also cheaper," he explained.

To do the test, saliva can be collected in cheaper collection tubes. Even raw saliva samples collected in cheap plastic sterile tubes and stored properly proved to be as good as samples kept in special solutions, Dr Idaghdour added.

Individuals should avoid eating, drinking, chewing gum or smoking 30 minutes before the collection to get the most accurate reading. The new testing system has been used in some states in the US; however, to date, the UAE performs the nasopharyngeal tests. The team has now been collaborating with Seha, private laboratories, MBRU, Cleveland Clinic Abu Dhabi, and the National Reference Laboratory under protocols approved by the Department of Health in Abu Dhabi.