TORONTO -- Hosts of private social gatherings in York Region will now need to keep a list of their guests for contact tracing as part of two new public health measures put in place ahead of the long weekend.

In a news release issued Friday afternoon, officials said the region’s Medical Officer of Health Dr. Karim Kurji made two changes to COVID-19 measures to help curb the spread of COVID-19 amid a fourth wave of the pandemic.

The most notable is the addition of a new measure requiring anyone hosting a social gathering in a private residence or a commercial facility to keep a list of names and contact information for all attendees. The hosts must also be able to provide the list to public health officials within 24 hours of a request.

Anyone who fails to do so can face fines of up to $5,000 for every day the offence occurs.

The new measures come after public health officials struggled to obtain contact information for attendees of a basketball tournament held in Markham last week.

As of Aug. 27, seven COVID-19 cases had been linked to the tournament, resulting in a declaration of an outbreak.

A public notice was released by York Region Public Health due to a “delay in obtaining contact lists from the event organizer.”

"We've had problems with respect to getting the details of the individuals who have attended various sorts of gatherings, even gatherings within homes in private dwellings, and it is critical that we get this information in a timely way," Kurji told CP24 on Friday afternoon.

Kurji also amended a self-isolation rule requiring all close contacts to individuals testing positive for COVID-19 to isolate for 10 days.

Anyone exhibiting signs and symptoms of COVID-19 must also isolate for 10 days unless they receive a negative test result.

The new and amended section 22 orders come into effect at midnight.