The first comes from the word accord and refers to a harmonious combination of three or more musical notes. The second is an alteration of cord, taking its spelling from Greek chorda, "string, gut," by way of Latin. This is the mathematical chord—a line segment that joins two points on a curve
Nausea, vomiting, fever, abdominal pain, muscle aches and chills
I don't know the first part, but extra rain will let more mosquitoes (the primary transmitter) breed more.
Answer:
4 - Any substance that contains germs that can be transferred to and from one person to another