Recommendations from CDC
Public Heath Canada
"The Public Health Agency of Canada routinely recommends that Canadian international travellers consult their personal physician or a travel clinic prior to international travel, regardless of destination, for an individual risk assessment to determine their individual health risks and their need for vaccination, preventative medication, and personal protective measures.
The Public Health Agency of Canada recommends, as well, that travellers who become sick or feel unwell on their return to Canada should seek a medical assessment with their personal physician. Travellers should inform their physician, without being asked, that they have been travelling or living outside of Canada, and where they have been. "
Read them carefully and consult your doctor, do not take advice from these forums.
This is the most recent PHAC link (as of Dec 25, 2008
It may change anytime …
edit: 2007/11/16 updated link to CDC site.
edit: 2008/12/25 added current link to PHAC
edit:2010/06/27 added link to PHAC
edit: 2013/01/01 updated link to CDC site (specific to DR)