LHSC Introduces Variant of Concern Screening as Part of COVID-19 Lab Testing Services


The Pathology and Laboratory Medicine (PaLM) team at London Health Sciences Centre (LHSC) has introduced routine Variant of Concern (VOC) screening as part of its COVID-19 lab testing services. PaLM is now performing VOC screening on all samples received from southwestern Ontario that test positive for COVID-19. The addition of this service within our microbiology program is another important way that LHSC is supporting residents in our communities and the province’s efforts to add capacity to the health system.

“Public Health Ontario has been screening all positive cases from the entire province for variants of concern since February, but with the increasing demands of the third wave, additional laboratory support was needed,” says Dr. Mike Kadour (PhD), Chief Laboratory Officer at LHSC. “We were pleased to leverage the expertise of our microbiology laboratory team to aid in the effort to add additional capacity to Ontario’s COVID-19 laboratory testing system.”

PaLM is now routinely screening all COVID-19 samples that test positive for the N501Y and E484K mutations. N501Y mutation is present in the UK (B.1.1.7) variant, while E484K mutation is present in the South African (B.1.351) and Brazilian (P.1) variants.

Specimens with N501Y mutation alone are considered consistent with the UK (B.1.1.7) variant and will not be sequenced further. Specimens that have either both mutations or E484K alone will be forwarded to the Public Health Laboratory for additional sequencing and variant/lineage characterization.

For individuals in the community awaiting COVID-19 test results, the addition of VOC screening will not impact the current process of obtaining results. Community members awaiting a response will still receive either a positive or negative test result via the Ontario Health portal. Any identified variant results will be communicated separately to the appropriate public health unit for follow-up.

“We were keen to do our part to support the system as VOC screening is a critical surveillance tool,” notes Kadour. “It helps to uncover where the variants are spreading and at what rate, which allows the Province and local public health units to adapt measures and respond accordingly. From a hospital perspective, it also allows us to ensure we are leveraging the most effective patient management strategies, as well as better prevent or contain future outbreaks.”

PaLM continues to maintain the capacity to process up to 10,000 COVID-19 tests per day, while regularly meeting a 24-hour turn-around time for COVID-19 testing results.

PaLM is a joint venture of LHSC and St. Joseph’s Health Care London. The labs provide a comprehensive range of routine and specialized testing and clinical consultation for patient care within southwestern Ontario and beyond. Through the pandemic, PaLM has expanded its regional collaboration to include seven public health units, long term care/retirement home operators and primary care providers. This collaboration of professionals, technologists, leaders, ITS team members, support staff, and vendors is the true success of achieving new levels of testing for people in our region.