City public health to review COVID-19 contact tracing

Toronto to collaborate with province, hospitals to fix ‘serious issues in the system’

Toronto’s top doctor said Wednesday that contact tracing, which is key to containing the COVID-19 pandemic and has been criticized for being too slow, is under review.

“We know that there are serious issues in the system that require system fixes,” said Dr. Eileen de Villa, Toronto’s medical officer of health, responding to questions at a COVID-19 update at city hall.

“So we look forward to engaging with provincial partners and other partners in the province, hospitals and labs, to find those system fixes to this very complex issue.”

The success of what is called case investigation and contact management relies on a long string of tasks at different locations headed by different agencies — from individual medical professionals to COVID-19 testing sites to laboratories to public health officials. At every step along the way, the information is susceptible to weaknesses including how it is relayed, how long it takes to be relayed and how accurately it is relayed.

For example, it can take up to two-anda-half days for public health to be notified of a positive result. Another problem identified by de Villa is that the information for contacting people who have tested positive is sometimes incomplete. Once they are contacted, they are asked to try to remember their activities for up to two weeks prior.

“Any delay in time makes recalling and the memory function more difficult and that will have impact on our case and contact management efforts,” de Villa said.

The provincial goal is to reach 90 per cent of cases within 24 hours of them having been reported to Toronto Public Health. TPH had been reporting about 80 per cent, but de Villa said Wednesday that data shows that from May 27-29, public health was able to contact almost 90 per cent of new COVID-19 cases within 24 hours.

She said TPH has never dealt with anything on this scale before. On average, TPH manages about 45,000 cases of communicable diseases a year. So far, there have been almost 12,000 COVID-19 cases in the last three months in Toronto, in addition to the regular burden of communicable diseases. The number of staff working on case and contact management has been increased to 550 from 50, de Villa said.

She added that TPH has worked on virtually every aspect of contact tracing that it has control of.

Her comments were made on the heels of an announcement by Mayor John Tory that food trucks and ice cream trucks could begin operating again, effective Wednesday.