If transmission of a disease involves an intermediate host such as a flea or mosquito, the transmission is called:

The term used to describe the transmission of a disease through an intermediate host, such as a flea or mosquito, is indeed "vector-borne." This type of transmission occurs when a disease-carrying organism, known as a vector, transfers pathogens from one host to another. In this scenario, the flea or mosquito acts as the vector that carries the infectious agent, facilitating its spread between hosts.

Understanding vector-borne transmission is crucial in the context of disease prevention and control, as it highlights the importance of managing the population of vectors and protecting individuals from bites. This approach helps reduce the incidence of diseases transmitted by these organisms, such as malaria or dengue fever.

The other terms refer to different modes of disease transmission. For instance, indirect transmission involves the spread of disease through contaminated surfaces or objects, airborne transmission refers to diseases spread through the air in tiny droplets, and direct transmission occurs through contact between an infected person and a susceptible person. Each mode of transmission requires different strategies for intervention and prevention, emphasizing the importance of accurately identifying the transmission route.