In terms of having people available at the border when a land traveller is coming across the border, the screening officer, if he sees that someone is ill, will require the person to have a consult with a quarantine officer. Each person is screened by a screening officer. If the person appears to be ill, then at his discretion, he can refuse entry or he can call the quarantine officer to make a further assessment.
On April 18th, 2007. See this statement in context.