cholera – n. a serious disease that causes severe vomiting and diarrhea and that often results in death​

contaminate – v. to make something dangerous, dirty, or impure by adding something harmful or undesirable to it​

defecate – v. to pass solid waste from the body​

drought – n. a long period of time during which there is very little or no rain​

epidemiologist – n. the study of how disease spreads and can be controlled​

phenomenon – n. something that can be observed and studied and that typically is unusual or difficult to understand or explain fully​

advance –adj. before something happens​