An outbreak — a sudden, concentrated occurrence or spread of disease (often used for epidemics or similar events).
新型ウイルスのアウトブレイクが市内で報告された。
An outbreak of a novel virus was reported in the city.
夏場に食中毒のアウトブレイクが起き、保健所が調査を開始した。
A food-poisoning outbreak occurred during the summer, and the health center started an investigation.
ワクチン接種が進んだことでアウトブレイクは抑えられた。
With vaccination progressed, the outbreak was brought under control.