I have an autoimmune disease in my colon that is triggered by stress. 

Its the equivalent of people who go to web MD then show up in the ER and tell me what's wrong w them.Everyone all of a sudden has all these rare diseases.

For example, if swine flu or some other major infectious disease started killing millions of people, the country could come to a halt.

However, considering a 4-plex configuration (2up, 2down) the access is via exterior stairs and that's no exposure at all.IMO, all parties (LL, allergic prospect & all others) are responsible for themselves and other than criminal activities and communicable diseases, owe nothing to the other - - and we still get back to "How was I to know?"

She goes on to say, he has an immune disease where his body is attacking him and they're seeing an oncologist.

Only mention it as you said long-term tenant, so he might be older....http://www.prnewswire.com/news-releases/be-aware-of-heart-disease-risk-factors-before-shoveling-snow-236097051.html

(They will never forget)5.)DEEP - Have emotional meaning to your name6.)SUPPORTED - Providing exemplary service makes a name or service contagious.lol, the more I go on the more is sounds like a diseases.

Basically, will the economic harm being created by the lock downs be worse than the disease itself?

It reminds me of the TV ads that promote a drug to cure some minor disease. 

Workers’ Occupational Diseases Act 2.