noun
direct infection; direct transmission
Medical term for the spread of a pathogen directly from one host to another without an intermediate vector.
直接伝染は、感染者との接触によって起こる。
Direct infection occurs through contact with an infected person.
間接伝染 refers to indirect transmission via vectors or contaminated objects, while 直接伝染 is direct host-to-host spread.
Compound of 直接 (direct) and 伝染 (infection, contagion).