The likely terms are contagious, infectious, communicable, or transmissible.
It is your ability to spread disease from one person to another.
An epidemic in a regional area, if spread around the world it is called a pandemic.
cancer
(noun or noun adjunct) "The disease spread rapidly and there was no cure." "Measles is a viral disease that usually affects children." "The disease organism in many of the cases was a mutated bacteria."
Epidemiologist is, I believe, the word you were looking for.
This was a very vague question, but I belive the word you are looking for is "Plague"
Sportsmanship is a word substitute for spirit of game
There is no one-word substitute in English for "son-in-law."
A word substitute for the sentence "A fault that can be forgiven" is "venial".
Zoonosis is the term used to describe diseases that can be transmitted from animals to humans.
One possible substitute for "their" is "his" or "her" depending on the gender of the person/people being referred to. Another substitute can be "its" when referring to a non-human object or entity.
The word Leptospirose is the French word for the disease known as Leptospirosis in English. This is a disease that is transmitted from animals to people, often through water that has been contaminated by animal urine. If this comes in contact with a lesion, eye or mucus membrane infection can occur.