What is a key characteristic of vector-borne diseases?

Vector-borne diseases are specifically characterized by their transmission mechanisms, which involve living carriers, often arthropods like mosquitoes, ticks, or fleas. These vectors are crucial for the lifecycle of the pathogens that cause the diseases, as they often acquire the pathogen from an infected host and subsequently transmit it to another host. This characteristic highlights the role of vectors not merely as passive carriers, but as active participants in the disease transmission cycle.

The other options do not accurately describe vector-borne diseases. While direct contact can be a pathway for some infectious diseases, it is not a feature of vector-borne transmission. Additionally, vector-borne diseases are not limited to rural areas and can occur in urban settings as well, especially with increased human-vector interactions. Lastly, while some diseases can indeed spread through contaminated water, this is unrelated to the mechanism of vector transmission, which relies on living organisms rather than water as a medium for spread.