The likely terms are contagious, infectious, communicable, or transmissible.
The term for the spread of disease is "epidemiology." This field studies how diseases are distributed in populations and the factors that influence their spread. Another related term is "transmission," which specifically refers to the process by which a disease spreads from one individual to another.
The standard definitions is "(of a disease or disease-causing organism) likely to be transmitted to people, organisms, etc., through the environment."It has come to mean " likely to spread or influence others in a rapid manner."
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"
The word pathogen means to be disease causing.
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".