Via the government of Canada: Protecting the Health and Safety of Canadians. Excerpt and then a comment:
Canada’s Citizenship and Immigration Minister Chris Alexander today announced new precautionary measures to protect the health and safety of Canadians.
Effective immediately, Canadian visa officers have temporarily paused the processing of visa applications from foreign nationals who have been physically present in a country designated by the World Health Organization (WHO) as having widespread and intense transmission of the Ebola virus. Discretion will remain for the Minister of Citizenship and Immigration to grant entry on a case-by-case basis in exceptional cases where travel is essential and in Canada’s interest.
Apart from those instances, temporary resident applications already in process that are affected by these new measures will be returned to the applicants.
Canadian citizens, permanent residents, foreign nationals currently in possession of a visa and foreign nationals who do not require visas will continue to be screened at ports of entry in Canada and will be subject to appropriate health screening and other measures under the Quarantine Act.
These changes do not impact Canadians currently in West Africa. All Canadians, including health-care workers, currently in West Africa will be permitted to travel back to Canada. The Government of Canada continues to advise against travel to countries designated by the WHO as having widespread and intense transmission of the Ebola virus.
This is an interesting spin on WHO's International Health Regulations, which specifically do not forbid trade and travel to and from countries under a notice of Public Health Emergency of International Concern.