As anyone who is not brain dead (which may exclude certain pols) must know, there is ZERO logical relationship between where one holds citizenship and the risk that you are a carrier of SARS. The issue is not where you hold citizenship but where you have recently lived and/or traveled.
Canada is a huge country. The SARS outbreak there is directly linked to a group of people who traveled from Asia and landed in Toronto. Everyone who has gotten sick is either one of those travelers, a health care provider, or a family member or close associate of one of those travelers (or of one of the foregoing.)
Only one person has been diagnosed with SARS in India (and I believe that was a presumptive diagnosis, not clear that it was ever confirmed.)
There is no logic in banning tourists with Canadian or Indian passports. None.