Definition: In this task, you need to generate an appropriate title for the given summary of some paragraph. The generated title must be short and should include the main topic of the given text. Your summary should be less than 20 words long.
Input: The number of suspected cases of cholera resulting from an epidemic in war-torn Yemen has reached 500,000, the World Health Organization (WHO) says.

Yemen cholera epidemic: Cases exceed 500,000 in four months