outbreak – n. a sudden start or increase of fighting or disease

sewage – n. wastewater and human waste products

sample – n. a small amount of something that represents what it is like

significant – adj. important or noticeable

dilute – v. to make a liquid thinner or weaker by adding water or another liquid to it

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

isolate – v. to put or keep (someone or something) in a place or situation that is separate from others