LONDON, ONT. -- Increasingly entrenched in our region, COVID-19 ‘variants of concern’ accounted for between 20 and 30 per cent of new cases detected in London and Middlesex County last week.

That compares to almost no variants being detected by the Middlesex-London Health Unit (MLHU) the previous week, with counts ranging between zero and five per cent.

“We know that the variants of concern are becoming an important factor locally,” MLHU Medical Officer of Health Dr. Chris Mackie told a regularly scheduled media briefing Monday.

The variants of concern spread more easily than the original virus.

“That’s definitely a significant development,” says Mackie. “It’s part of why we are seeing out case counts climb again.”

On Monday, the MLHU reported 27 new cases and one death.

Contact tracing reveals that the recently detected cases of the variants are the result of contact with an infected individual in the community, not travel.

Detecting variants of concern requires secondary laboratory analysis that takes 48 to 72 hours.

Identifying the specific variant requires further analysis of its genetic fingerprint.

“It takes another week, sometimes more, to get the genome sequencing back,” added Mackie.

That lag time means variants were likely spreading within the community prior to last week.

And at least two variant cases have been detected in schools, at Saunders Secondary School and Sir Frederick Banting Secondary School.