Vektorivälitys

Vektorivälitys, often translated as vector transmission, is a method of disease spread where an infectious agent is transmitted from one organism to another by a living carrier, typically an arthropod like a mosquito, tick, or flea. The vector itself becomes infected by feeding on an infected host. The pathogen then replicates or undergoes development within the vector before being transmitted to a new, susceptible host. This transmission usually occurs when the vector bites the new host, introducing the pathogen through its saliva or through regurgitation.

The pathogen's relationship with the vector can vary. In some cases, the pathogen is simply carried on the vector's mouthparts or body and transferred mechanically. More commonly, the pathogen is internalized by the vector and undergoes a biological cycle within it. This biological transmission is often essential for the pathogen to become infectious to a new host. Examples of diseases transmitted this way include malaria (mosquito-borne), Lyme disease (tick-borne), and plague (flea-borne). Understanding vektorivälitys is crucial for controlling vector-borne diseases, as it involves targeting not only the pathogen but also the vector population and their interactions with hosts.