Actually, spouses
and dependant children are excessive demand (medically) exempt (see: http://www.cic.gc.ca/english/resources/manuals/op/op02-eng.pdf 5:20)
Whilst they are excessive demand (medically) exempt, they cannot be a danger to "public health or public safety"
5.19. Medical requirements
Members of the family class are medically inadmissible if they or their family members are likely to be a danger to public health or to public safety or if their admission might reasonably be expected to cause excessive demands on health or social services [A38(1)]. See Exceptions to medical inadmissibility, Section 5.20 below.
5.20. Exceptions to medical inadmissibility
A38(2)(a) states that
spouses, common-law partners and dependent children who are members of the family class are not inadmissible even if they have a
medical condition that will result in excessive demand to health or social services.
For examples of being a danger to public health or public safety see: http://www.cic.gc.ca/english//resources/publications/dmp-handbook/appendix-02.asp section 6:3
6.3 Applicants identified as being excessive demand exempt may require further investigation to determine whether they present a risk to the public health or safety of Canadians. Active tuberculosis and untreated syphilis are examples of medical conditions that present a risk to the public health in Canada. Conditions that pose a threat to public safety in Canada might include:
certain impulsive sociopathic behaviour disorders
some aberrant sexual disorders such as pedophilia
certain paranoid states
some organic brain syndromes associated with violence or risk of harm to others
applicants with substance abuse leading to antisocial behaviour such as violence, impaired driving, or other types of hostile, disruptive behaviour
However, regarding public health, should someone be found to have TB etc., they would be placed under medical surveillance and it would not result in a refusal of PR.
The many threads about children being medically inadmissible are likely to be from people who are applying under federal skilled worker, PNP or other economic classes, not as family sponsorship applications.
