The research, led by the Instituto Gulbenkian de Ciência and which brought together the Centro Hospitalar Universitário de Lisboa Central (CHULC) – Hospital Dona Estefânia Hospital and the Hospital Professor Doutor Fernando da Fonseca, demonstrated that saliva can be used effectively in the diagnosis of SARS-CoV- 2. The saliva test developed, combined with a molecular PCR test, has a sensitivity similar to that of current tests with nasopharyngeal samples and substantially superior to that of rapid antigen tests.
The procedure was validated, in a first stage, in 49 adults admitted to Hospital Professor Doutor Fernando da Fonseca with pathologies related or not related to COVID-19 and, in a second stage, in 85 children, up to 10 years of age, admitted to CHULC – Hospital Dona Estefânia between August 25, 2020 and June 20, 2021.
For Maria João Amorim, researcher at the IGC and coordinator of the study, “we demonstrate that this method is as effective as tests that use nasopharyngeal samples”. According to Marta Alenquer, IGC researcher and first author of the article available in bioRxiv, “this test also revealed another associated benefit: the possibility of omitting the RNA extraction step, which substantially reduces the time and costs associated with performing the analysis and increases testing capacity.”
At this stage in the COVID-19 pandemic, screening for SARS-CoV-2 in school settings is critical to breaking transmission chains and, at the same time, understanding the role of children in community-based transmission of the virus and in the development of new variants . It is therefore critical to implement comprehensive testing methods that are easy to perform, but also highly sensitive and specific.
“The collection using nasopharyngeal swabs is an invasive and uncomfortable technique, especially for children, and it requires experienced professionals, so it is not always easy to perform” explains Maria João Brito, head of the Infectious Unit of CHULC – Hospital de Dona Estefânia. The use of saliva is a less invasive alternative that requires less logistics, and it can be collected by the child or with the assistance of parents or teachers.
The SPP Grand Prize, a distinction from the Portuguese Society of Pediatrics, was awarded during the last annual congress, held at the end of October.
In parallel, the method developed is already being implemented at the Instituto Gulbenkian de Ciência as a way of monitoring the institution’s employees, having proved to be decisive in identifying infected people and in adopting measures to contain contacts and interrupt transmission.