OTTAWA -- Ottawa Public Health says one person going to work and attending a family gathering resulted in 15 cases of COVID-19 and forced 40 people to self-isolate

The health unit’s latest real-world example of contact tracing illustrates how COVID-19 can spread at family gatherings and in the workplace.

On Twitter, Ottawa Public Health said one person with COVID-19 went to work before developing symptoms of COVID-19.

"Two days later, after mild symptoms developed, they attended a family gathering and had a friend over," said OPH.

Within two weeks, 15 people tested positive for COVID-19 and 40 individuals who were identified as high risk contacts needed to self-isolate.

There were six cases of COVID-19 at an Ottawa workplace. Ottawa Public Health says there was inconsistent mask use, inconsistent physical distancing and some employees at the workplace shared a meal inside together.

The family gathering resulted in six cases of COVID-19 in four households. Public health says separate households gathered inside to celebrate and share a meal, with no mask use or physical distancing.

"We're naturally more relaxed around people we're close to, but this cluster is a reminder that COVID doesn't care how well we know someone," said Ottawa Public Health on Twitter.

"Whether around coworkers we've known for years, friends or family members, we must remain vigilant. P.S. gatherings with four households = no."