IPA: /ˌɔːtəʊɪnˈfɛkʃən/
KK: /ɔːtəʊɪnˈfɛkʃən/
A type of infection that occurs when pathogens, like bacteria or parasites, that are already present in the body cause a new infection or reinfection.
The patient experienced autoinfection due to the presence of dormant parasites in his system.
Autoinfection is formed from "auto-" (meaning self) and "infection" (from Latin "infectio", meaning to taint or contaminate). The word describes a process where an infection is caused by the organism's own pathogens.
Think of 'self' ('auto-') causing an 'infection' — that's why autoinfection means an infection caused by one's own germs.