How saliva-based COVID-19 PCR tests ensure children’s safety in Abu Dhabi?
Abu Dhabi: An Abu Dhabi laboratory that is the only facility in the emirate authorised to provide saliva-based PCR testing for COVID-19 has already performed more than 50,000 of the non-invasive tests, and expects to ramp up the numbers significantly over the next few months.
Biogenix Labs is part of G42 Healthcare, an Abu Dhabi-based health-tech company that has spearheaded the concerted efforts to combat COVID-19 in the UAE. The 4,000-square metre high-throughput facility located in Masdar City is also enabling the sequencing of COVID-19 variants in the UAE, Dr Sally Mahmoud, laboratory director and clinical pathologist at the facility, told Gulf News.
“Children are often asymptomatic carriers of COVID-19 and it is important to test them in order to limit the spread of COVID-19. Since the start of the outbreak, it has also been important to get them back to school, but the discomfort of nasopharyngeal swabs for PCR testing proved to be a hurdle,” Dr. Mahmoud said. “This is why we piloted and tested the efficacy of saliva-based testing before rolling it out for schoolchildren and school-aged travellers returning to the UAE,” she said.
For the pilot scheme, the lab conducted two phases of the saliva PCR pilot screening process in schools, during which up to 2,000 students aged up to 12 years were tested. Children under 12 years old had previously been exempted from PCR testing. With positive reactions to the saliva-based testing and clinical results showing 90 per cent sensitivity — meaning they provided true results 90 per cent of the time — the test was rolled out as a requirement for children who had travelled abroad before returning to school campuses in January.
The test is now available for children, by appointment, at Biogenix Labs, and can also be requested by elderly residents. It requires the person being tested to expel saliva into a sterile container, and the sample is then PCR-tested at the lab.
Ease of saliva-testing:-
“The test is non-invasive, and highly sensitive. We also do not have to extract the genetic material in the lab first before testing for the virus, so this makes the processing faster,” Dr. Mahmoud said.
Compared to regular PCR testing via nasal swabs, saliva-based testing is also easier because it does not require a stabiliser. Saliva is stable on its own at room temperatures up to 25 degrees Celsius, so samples can be easily transported without an enrichment medium, unlike nasal swab samples, and can be stored in the refrigerator for up to seven days. “The only thing we require is for saliva not to be contaminated by food or diluted by water, so we require the individual to be fasting for 30 to 45 minutes before taking the test,” the lab director explained.
Saliva-based testing has another advantage: the quality of the sample is not affected by how the medical professional collects it, whereas a nasal swab must be properly performed to ensure a good sample quality.
Enabling safe schooling:-
“[After a prolonged period of distance learning amid the pandemic,] it was essential that we put children back in school, but there were known risks. Children tend to remove their masks, and they don’t always follow hand hygiene or COVID precautions, and no matter how much you try to stop them, they get close to one another. This is why saliva-based testing is so beneficial,” Dr Mahmoud said.
School-related testing is carried out in collaboration with the education regulator, the Abu Dhabi Department of Education and Knowledge (ADEK), and the emirate’s health regulator, the Department of Health — Abu Dhabi (DoH). “In fact, saliva testing is so non-invasive that many adults would like to take it, but at the moment, the nasopharyngeal swab is the approved method,” Dr. Mahmoud added.
The lab also offers nasopharyngeal COVID-19 PCR-testing for school-going children aged over 12 years. Dr. Mahmoud said that students in these age groups who are vaccinated are screened every two weeks, and those who have not received the COVID-19 vaccine are tested every week, in accordance with ADEK and DoH regulations. The lab provides testing for more than 300 schools in the emirate, with each school being assigned a designated day or two for testing according to the number of students undergoing the test.
COVID-19 combat efforts:-
Constructed and put into operation within just 10 days at the start of the pandemic, the Biogenix Labs also participated in testing to facilitate the 4Humanity Phase III vaccine trials for the Sinopharm vaccine in the UAE. Processing 30,000 PCR tests a day, it is now working to develop rapid COVID-19 testing solutions, and carrying out a full range of clinical trials.
“The capacity for PCR testing in the UAE exceeds most countries with a similar population. Most labs are very well-equipped and quality guidance and governance from the health authorities makes the testing very controlled. The development of the Al Hosn app and automation of result uploads has also allowed for a thorough awareness of the number of COVID-19 cases, and enabled efficient contact tracing. The robust system also assigns safe quarantine periods for contacts. This is not the case in many other countries,” Dr Mahmoud said.
“What we have in term in terms of capacity and support is also amazing, and it allows the UAE to apply high-quality PCR testing while many other countries are instead relying on lower-quality tests,” she added.
A higher level of care:-
Dr. Mahmoud said that Biogenix Labs is also expanding its services for clinical genomics and sequencing as part of the UAE’s Genome Programme, a national project set to use large-scale genomic data to improve health and well-being. “The COVID-19 pandemic has elevated the UAE into a higher level of health care provision and infectious disease management, and we are happy to be supporting all efforts with regard to this. In future, these new capabilities will surely enable a proactive approach to any health care crisis,” she added.