Toronto Public Health has suspended contact tracing for some coronavirus cases as the city struggles with a “high level” of infections.Contact tracing, which is when public health units reach out to close contacts of a confirmed coronavirus case to warn them of potential exposure and in turn take appropriate action, is viewed by experts as a key to combatting virus spread.“As part of the usual course of outbreak management, when cases reach a high level, public health must make a strategic shift and temporarily re-prioritize case and contact management to focus on the highest-risk scenarios,” a TPH spokesperson said in a statement Saturday.