Translation guide
How to express 'outbreak' in Japanese depends on what is breaking out: a disease, war, fire, or something else. The most common and versatile word is 発生 (hassei), but specific contexts call for different terms.
To refer to the sudden occurrence of a disease affecting many people.
General term for outbreak, occurrence, or incidence. Used for diseases, but also for other events. Often combined with the disease name.
An outbreak of the novel coronavirus was reported.
Epidemic, prevalence, spread. Emphasizes the widespread nature of a disease. Often used for seasonal influenza.
Loanword from English, used in technical or news contexts, especially for sudden, severe outbreaks.
To refer to the start of a war, battle, or hostilities.
Outbreak (of war, conflict). A formal, written term. Commonly used in historical or news contexts.
To refer to the sudden start of a fire.
Also used for fires. Often in official reports.
To refer to the sudden start of violent events or social unrest.
Used for sudden outbreaks of violence, riots, etc. Formal.
To refer to the sudden appearance or increase of something like insects, storms, etc.
Prevent the outbreak of infectious diseases.
インフルエンザの流行が始まった。
An influenza outbreak has begun.
An Ebola outbreak occurred.
Literally 'war begins'. A more neutral, everyday expression.
Suddenly, war broke out.
A fire broke out.
Common, everyday expression for a fire occurring.
A fire broke out in the neighborhood last night.
A riot broke out.
More general: 'violent incidents occur/break out'.
Violent incidents broke out in the city.
General term for occurrence, including pests, tornadoes, etc.
There was an outbreak of pests.
Frequent occurrence, outbreak of many cases. Often used for accidents or incidents.
Tornadoes are breaking out frequently.
An infectious disease outbreak occurred.
In many cases, Japanese uses a verb like 発生する (hassei suru) or 起きる (okiru) instead of a noun. For example, 'There was an outbreak' is often '発生した' (hassei shita).