Translation guide
The spread of disease, or a harmful influence or idea that spreads. Japanese distinguishes between medical contagion and metaphorical contagion, and often uses different words for the disease itself, the act of spreading, and the abstract concept.
The transmission of an infectious disease from person to person.
The most common and general term for infection or contagion. Can refer to the act of becoming infected or the state of being infected. Used in medical and everyday contexts.
The contagion is spreading.
Identify the route of contagion.
Specifically refers to contagion or transmission of a disease. Often used in compounds like 伝染病 (contagious disease). Slightly more technical than 感染.
This disease is highly contagious.
Direct contact contagion. Used in medical contexts to specify the mode of transmission.
Wash hands to prevent contagion by contact.
Droplet contagion. Technical term for transmission via respiratory droplets.
Be careful of droplet contagion.
The rapid spread of something non-physical, like fear, panic, or economic instability.
Also used metaphorically for the spread of emotions, ideas, or behaviors, similar to 'contagious' in English. Often used in phrases like 感情の伝染 (emotional contagion).
Spread or ripple effect, often used for economic contagion or the spread of effects from one area to another. Implies a chain reaction.
Chain reaction or linkage. Used for contagion in the sense of a series of connected events, like financial contagion or a chain of failures.
A disease that is spread by contagion.
感染 (kansen) focuses on the entry of a pathogen into a host and the resulting infection, while 伝染 (densen) emphasizes the transmission from one individual to another. In many contexts they overlap, but 感染 is more common for 'getting infected' and 伝染 for 'being contagious' or spreading. For metaphorical use, 伝染 is preferred.
The English word 'contagion' is often used as a mass noun or abstract concept. In Japanese, it is usually more natural to use a verb phrase (感染する, 伝染する) or a compound noun (感染症, 伝染病) rather than a single abstract noun. Avoid directly translating 'contagion' as a standalone noun unless the context is very abstract.
金融危機の波及を防ぐ。
Prevent the contagion of the financial crisis.
contagion of bank failures
emerging contagion