BARRIE, ONT. -- The Simcoe Muskoka health unit reports an alarming trend in people under 35 testing positive for COVID-19.

The health unit says while the senior community is most at risk, adults between 18 and 34 have had the highest infection rate since June.

There are four new cases reported in the past 24 hours, two Barrie residents, a New Tecumseth man and a Bracebridge woman.

This week, 45 people tested positive for the virus across the region, with more than half being under 34 years of age.

The health unit says the week of Sept. 13 had 52 lab-confirmed cases, the second-highest weekly number of cases since the beginning of the pandemic.

Meanwhile, the province reported 409 new cases in the last 24 hours and one new virus-related death.

According to the health minister, 65 per cent of the new diagnoses across Ontario are people under 40.

The government is also reporting 29 new school-related cases on Friday, including at least 10 students.

Five schools in Simcoe Muskoka have reported positive cases: Sister Catherine Donnelly Catholic School, Father F.X. O'Reilly Catholic School, St. John Vianney Catholic School, Bear Creek Secondary School, and Twin Lakes Secondary School.

With files from The Canadian Press