Development, validation, and implementation of a saline gargle test for COVID-19

BC was one of the first jurisdictions in the world to implement a saline rinse-gargle (“saline gargle”) collection method for COVID-19 testing, arising out the need to implement a nasopharyngeal (NP) swab-independent method to test for for COVID-19. Over extensive literature reviews, brainstorming, and discussions, saline gargle evolved to be a highly possible swab-independent option. Laboratory testing of PCR performance, stability, and appropriateness of the saline gargle was evaluated. Saline gargle performed well compared to the standard nasopharyngeal swab and viral transport media system.

Following the analytical validation of the sample type, a clinical validation was led by BC Children’s Hospital, which required volunteers to provide matched NP swabs, saline gargle, and saliva specimens for parallel testing. The clinical validation demonstrated that interpretation of nucleic acid test results were equivalent for the NP swab and saline gargle, while saliva was shown to have lower clinical sensitivity, particularly for pediatric patients. As part of the clinical validation findings, participants ranked saline gargle collection as the preferred collection method, adding to the rationale for selecting it as a testing option. A collaborative province-wide cross-validation study involving all COVID-19 testing laboratories across the province confirmed that saline gargle specimens were compatible with all COVID-19 nucleic acid-based testing platforms present in BC. 

Provincial Laboratory Medicine Services recommended the adoption of saline gargle for school-aged children and youth across BC, and provincial implementation started on 17 September, 2020, with representatives from laboratories, BC Children’s Hospital, BCCDC, public health, COVID collection centres, and PHSA Supply Chain created written collection instructions and an accompanying collection video, updated guidance documents, trained front-line staff, and sourced supplies. In November 2020, the approach was made available to adults.

In 2020, the team received a CICH Global Health Seed Grant to support the validation, implementation and operationalization of gargle sample collection for COVID-19 testing in Botswana.The results may be used to inform national scale-up and as a pilot feasibility study for the WHO Regional Office for Africa and the African CDC.

Project Status
Lead Institution
BC Children's Hospital Research Institute and Botswana Harvard AIDS Institute Partnership
Lead (no profile)
Margaret Mokomane
Collaborator (No Profile)
Kwana Lechiile
Unami Mulale
Mosepele Mosepele
Jonathan Strysko
Margaret Bafana
Michelle Dittrick


  • Prevention, Population and Public Health

First Nations land acknowledegement

Action on Sepsis operates on the traditional, ancestral, and unceded territory of the Coast Salish peoples — xʷməθkʷəy̓əm (Musqueam), Sḵwx̱wú7mesh (Squamish), and Səl̓ílwətaʔ/Selilwitulh (Tsleil-Waututh) Nations. We invite everyone to reflect on the traditional territories and land that they currently work and live on.

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