When a worker or anyone else at the workplace is unwell and the illness could pass to others (a respiratory or gastrointestinal illness, say), the PCBU should help the person get medical treatment where needed, see that they leave the workplace as soon as they can and stay away until they are no longer a risk of spreading it, keep them separated from others where sending them away is not reasonably practicable, support workers to work from home where the job allows and they feel well enough or to take leave under their entitlements, and supply suitable PPE such as a P2/N95 respirator when it is needed, making sure people know how to wear it. Anyone in close contact with the unwell person, first aiders and the people cleaning up after them for example, must be protected so far as reasonably practicable. Where a worker reveals that they have, or think they have, an infection that spreads readily, it may be right to tell others who were near them during the likely infectious period so they can watch for symptoms, bearing in mind the PCBU's privacy duties toward the worker.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.