OTTAWA -- Seven OC Transpo employees tested positive for COVID-19 between Aug. 9 and 15, with another new case of novel coronavirus reported by the City of Ottawa's transit service on Sunday.

In a memo to council, Transportation Services General Manager John Manconi said the transit service received confirmation Sunday afternoon that a transit operator tested positive for COVID-19. It was the fourth positive test involving a bus driver announced by the transit service since Aug. 9.

The Transit Service confirms to CTV News Ottawa that seven employees tested positive for COVID-19 between Aug. 9 and 15, including three operators and four employees that do not have contact with the public.

"Of the almost 3,000 employees at OC Transpo, seven employees tested positive for COVID-19 between Aug. 9 and 15," said Director of Transit Operations Jim Greer in a statement to CTV News Ottawa Sunday afternoon.

"Three of these employees were bus operators who drove in service buses and the remainder did not have contact with the public. This brings the total number of cases at OC Transpo since the pandemic began to 21."

Greer adds that OC Transpo advises staff and unions when an employee that doesn't have contact with the public tests positive for COVID-19.

"The safety of our customers and employees is our top priority, and that is why, out of an abundance of caution, we take additional precautionary measures including providing notification to City Council, Transit Commission, the public and the media when an employee who works directly with the public tests positive for COVID-19. When an employee has no public contact as part of their duties, we take the added precaution of advising our staff and unions."

In memos to council and the media, Manconi announced on Aug. 10, Aug. 11 and Aug. 14 that drivers had tested positive for COVID-19. The fourth case involving a driver, and the eighth case in eight days at OC Transpo, was announced on Sunday.

"OC Transpo and Ottawa Public Health work closely on every case of an employee who tests positive for COVID-19 and OPH staff are aware of our total case numbers," said Greer in the statement.

Ottawa Public Health told CTV News Ottawa last week that there have been no confirmed cases of COVID-19 linked to transit use.