Abnormal Host
An abnormal host is a broad term for a host that is not the parasite’s usual (typical) host. In parasitology, this generally includes two more precise categories: accidental hosts and aberrant hosts.
Because “abnormal host” doesn’t specify whether the parasite can develop successfully, many references recommend using accidental or aberrant instead for clarity.
Why it matters: Many zoonotic infections involve humans as abnormal hosts, which can change disease presentation and disrupt the parasite’s ability to complete transmission.
