outbreak

noun
  1. A sudden occurrence of something unwelcome, such as war or disease. noun
    The outbreak of the disease caused widespread panic.
    There was an outbreak of violence in the city after the match.
  2. A sudden increase in the number of cases of a disease above what is normally expected in that population in that area. noun
    The health department is investigating the outbreak of measles in the community.
    An outbreak of food poisoning was traced back to the contaminated restaurant.