What term refers to an organism, such as a mosquito or tick, that transmits diseases?

The term that identifies an organism, like a mosquito or tick, that transmits diseases is "vector." Vectors are crucial in the transmission cycle of various pathogens, as they facilitate the spread of diseases from one host to another. Mosquitoes, for instance, act as vectors for diseases such as malaria, West Nile virus, and dengue fever by biting humans and other animals, thereby transferring infectious agents.

A carrier can refer to a person or animal that harbors a disease-causing organism without exhibiting symptoms, thus not explicitly describing the mechanism of transmission. Pathogens are the actual microorganisms (such as bacteria, viruses, or parasites) that cause disease, not the intermediary organisms that spread them. A host is typically defined as an organism that harbors a pathogen and may or may not exhibit symptoms of disease, further distinguishing it from the role of a vector in disease transmission.