app – n. a program for a smartphone or other device that performs a special function

isolate – v. to separate from other people or things

trace – v. to find the origin of something

fellow – adj. used to describe people who share the same interests or situation

location – n. a place or position

transmission – n. the process of passing something from one person to another

positive – adj. in a medical test, positive means the person being tested has a disease or condition